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نشرة الممارس الصحي نشرة معلومات المريض بالعربية نشرة معلومات المريض بالانجليزية صور الدواء بيانات الدواء
  SFDA PIL (Patient Information Leaflet (PIL) are under review by Saudi Food and Drug Authority)

Treatment of men with erectile dysfunction, which is the inability to achieve or maintain a penile
erection sufficient for satisfactory sexual performance.
In order for VIRECTA to be effective, sexual stimulation is required.
- PHARMACOLOGICAL PROPERTIES
- Pharmacodynamic properties:
Pharmacotherapeutic group: Drugs used in erectile dysfunction. ATC Code: G04B E03.
Sildenafil is an oral therapy for erectile dysfunction. In the natural setting, i.e. with sexual stimulation,
it restores impaired erectile function by increasing blood flow to the penis.
The physiological mechanism responsible for erection of the penis involves the release of nitric oxide (NO) in the corpus cavernosum during sexual stimulation. Nitric oxide then activates the enzyme guanylate cyclase, which results in increased levels of cyclic guanosine monophosphate (cGMP),
producing smooth muscle relaxation in the corpus cavernosum and allowing inflow of blood.
Sildenafil is a potent and selective inhibitor of cGMP specific phosphodiesterase type 5 (PDE5) in the corpus cavernosum, where PDE5 is responsible for degradation of cGMP. Sildenafil has a peripheral site of action on erections. Sildenafil has no direct relaxant effect on isolated human corpus cavernosum but potently enhances the relaxant effect of NO on this tissue. When the NO/cGMP pathway is activated, as occurs with sexual stimulation, inhibition of PDE5 by sildenafil results in increased corpus cavernosum levels of cGMP. Therefore sexual stimulation is required in order for sildenafil to produce its intended beneficial pharmacological effects.
- Preclinical safety data:
Non-clinical data revealed no special hazard for humans based on conventional studies of safety pharmacology, repeated dose toxicity, genotoxicity, carcinogenic potential, and toxicity to reproduction.


Do not use VIRECTA if:
You are allergic (hypersensitive) to Sildenafil Citarte or any of the other ingredients listed in Section 6.
If you are not sure, talk to your doctor or pharmacist before using VIRECTA.
- The contraindications of VIRECTA:
Hypersensitivity to the active substance or to any of the excipients.
Consistent with its known effects on the nitric oxide/cyclic guanosine monophosphate (cGMP)
pathway, sildenafil was shown to potentiate the hypotensive effects of nitrates, and its coadministration
with nitric oxide donors (such as amyl nitrite) or nitrates in any form is therefore
contraindicated.
Agents for the treatment of erectile dysfunction, including sildenafil, should not be used in men for
whom sexual activity is inadvisable (e.g. patients with severe cardiovascular disorders such as
unstable angina or severe cardiac failure).
VIRECTA is contraindicated in patients who have loss of vision in one eye because of non-arteritic
anterior ischaemic optic neuropathy (NAION), regardless of whether this episode was in connection or
not with previous PDE5 inhibitor exposure.
The safety of sildenafil has not been studied in the following sub-groups of patients and its use is
therefore contraindicated: severe hepatic impairment, hypotension (blood pressure < 90/50 mmHg),
recent history of stroke or myocardial infarction and known hereditary degenerative retinal disorders
such as retinitis pigmentosa (a minority of these patients have genetic disorders of retinal
phosphodiesterases).
- The special warnings and precautions for use:
A medical history and physical examination should be undertaken to diagnose erectile dysfunction
and determine potential underlying causes, before pharmacological treatment is considered.
Prior to initiating any treatment for erectile dysfunction, physicians should consider the cardiovascular
status of their patients, since there is a degree of cardiac risk associated with sexual activity. Sildenafil
has vasodilator properties, resulting in mild and transient decreases in blood pressure. Prior to
prescribing sildenafil, physicians should carefully consider whether their patients with certain
underlying conditions could be adversely affected by such vasodilatory effects, especially in
combination with sexual activity. Patients with increased susceptibility to vasodilators include those
with left ventricular outflow obstruction (e.g., aortic stenosis, hypertrophic obstructive
cardiomyopathy), or those with the rare syndrome of multiple system atrophy manifesting as severely
impaired autonomic control of blood pressure.VIRECTA potentiates the hypotensive effect of nitrates.
Serious cardiovascular events, including myocardial infarction, unstable angina, sudden cardiac
death, ventricular arrhythmia, cerebrovascular haemorrhage, transient ischaemic attack, hypertension
and hypotension have been reported post-marketing in temporal association with the use of
VIRECTA. Most, but not all, of these patients had pre-existing cardiovascular risk factors. Many
events were reported to occur during or shortly after sexual intercourse and a few were reported to
occur shortly after the use of VIRECTA without sexual activity. It is not possible to determine whether
these events are related directly to these factors or to other factors.
Agents for the treatment of erectile dysfunction, including sildenafil, should be used with caution in
patients with anatomical deformation of the penis (such as angulation, cavernosal fibrosis or
Peyronie's disease), or in patients who have conditions which may predispose them to priapism (such
as sickle cell anaemia, multiple myeloma or leukaemia).
The safety and efficacy of combinations of sildenafil with other treatments for erectile dysfunction
have not been studied. Therefore the use of such combinations is not recommended.
Visual defects and cases of non-arteritic anterior ischaemic optic neuropathy have been reported in
connection with the intake of sildenafil and other PDE5 inhibitors. The Patient should be advised that
in case of sudden visual defect, he should stop taking VIRECTA and consult a physician immediately.
Co-administration of sildenafil with ritonavir is not advised.
Caution is advised when sildenafil is administered to patients taking an alpha-blocker, as the coadministration may lead to symptomatic hypotension in a few susceptible individuals. This is most likely to occur within 4 hours post sildenafil dosing. In order to minimise the potential for developing postural hypotension, patients should be hemodynamically stable on alpha-blocker therapy prior to initiating sildenafil treatment. Initiation of sildenafil at a dose of 25 mg should be considered. In addition, physicians should advise patients what to do in the event of postural hypotensive symptoms.
Studies with human platelets indicate that sildenafil potentiates the antiaggregatory effect of sodium nitroprusside in vitro. There is no safety information on the administration of sildenafil to patients with bleeding disorders or active peptic ulceration. Therefore sildenafil should be administered to these patients only after careful benefit-risk assessment.
VIRECTA is not indicated for use by women.
-The Interaction with other medicinal products and other forms of interaction:
Effects of other medicinal products on sildenafil
In vitro studies:
Sildenafil metabolism is principally mediated by the cytochrome P450 (CYP) isoforms 3A4 (major
route) and 2C9 (minor route). Therefore, inhibitors of these isoenzymes may reduce sildenafil
clearance.
Grapefruit juice is a weak inhibitor of CYP3A4 gut wall metabolism and may give rise to modest increases in plasma levels of sildenafil.
Single doses of antacid (magnesium hydroxide/aluminum hydroxide) did not affect the bioavailability of sildenafil.
Although specific interaction studies were not conducted for all medicinal products, population pharmacokinetic analysis showed no effect of concomitant treatment on sildenafil pharmacokinetics when grouped as CYP2C9 inhibitors (such as tolbutamide, warfarin, phenytoin), CYP2D6 inhibitors (such as selective serotonin reuptake inhibitors, tricyclic antidepressants), thiazide and related diuretics, loop and potassium sparing diuretics, angiotensin converting enzyme inhibitors, calcium
channel blockers, beta-adrenoreceptor antagonists or inducers of CYP450 metabolism (such as rifampicin, barbiturates).
Nicorandil is a hybrid of potassium channel activator and nitrate. Due to the nitrate component it has the potential to result in a serious interaction with sildenafil.
Effects of sildenafil on other medicinal products
In vitro studies:
Sildenafil is a weak inhibitor of the cytochrome P450 isoforms 1A2, 2C9, 2C19, 2D6, 2E1 and 3A4
(IC50 >150 μM). Given sildenafil peak plasma concentrations of approximately 1 μM after recommended doses, it is unlikely that VIRECTA will alter the clearance of substrates of these isoenzymes.
There are no data on the interaction of sildenafil and non-specific phosphodiesterase inhibitors such as theophylline or dipyridamole.
In vivo studies:
Consistent with its known effects on the nitric oxide/cGMP pathway, sildenafil was shown to potentiate the hypotensive effects of
nitrates, and its co-administration with nitric oxide donors or nitrates in any form is therefore contraindicated.
No significant interactions were shown when sildenafil (50 mg) was co-administered with tolbutamide (250 mg) or warfarin (40 mg), both
of which are metabolised by CYP2C9.
Sildenafil (50 mg) did not potentiate the increase in bleeding time caused by acetyl salicylic acid (150 mg).
Sildenafil (50 mg) did not potentiate the hypotensive effects of alcohol in healthy volunteers with mean maximum blood alcohol levels of
80 mg/dl.
Pooling of the following classes of antihypertensive medication; diuretics, beta-blockers, ACE inhibitors, angiotensin II antagonists, antihypertensive medicinal products (vasodilator and centrally-acting), adrenergic neurone blockers, calcium channel blockers and alpha-adrenoceptor blockers, showed no difference in the side effect profile in patients taking sildenafil compared to placebo treatment.
In a specific interaction study, where sildenafil (100 mg) was co-administered with amlodipine in hypertensive patients, there was an additional reduction on supine systolic blood pressure of 8 mmHg. The corresponding additional reduction in supine diastolic blood pressure was 7 mmHg. These additional blood pressure reductions were of a similar magnitude to those seen when sildenafil was administered alone to healthy volunteers.
Sildenafil (100 mg) did not affect the steady state pharmacokinetics of the HIV protease inhibitors, saquinavir and ritonavir, both of which are CYP3A4 substrates.
- Pregnancy and breast-feeding
VIRECTA is not indicated for use by women.
No relevant adverse effects were found in reproduction studies in rats and rabbits following oral administration of sildenafil.
-Effects on ability to drive and use machines:
No studies on the effects on the ability to drive and use machines have been performed.
As dizziness and altered vision were reported in clinical trials with sildenafil, patients should be aware of how they react to VIRECTA, before driving or operating machinery. 


For oral use.
Use in adults:
The recommended dose is 50 mg taken as needed approximately one hour before sexual activity. Based on efficacy and tolerability, the dose may be increased to 100 mg or decreased to 25 mg. The maximum recommended dose is 100 mg. The maximum recommended dosing frequency is once per day. If VIRECTA is taken with food, the onset of activity may be delayed compared to the fasted state.
Use in Elderly:
Dosage adjustments are not required in elderly patients.
Use in Patients with impaired renal function:
The dosing recommendations described in “Use in adults” apply to patients with mild to moderate renal impairment (creatinine clearance = 30-80 mL/min).
Since sildenafil clearance is reduced in patients with severe renal impairment (creatinine clearance < 30 mL/min) a 25 mg dose should be considered. Based on efficacy and tolerability, the dose may be increased to 50 mg and 100 mg.
Use in Patients with impaired hepatic function:
Since sildenafil clearance is reduced in patients with hepatic impairment (e.g. cirrhosis) a 25 mg dose should be considered. Based on efficacy and tolerability, the dose may be increased to 50 mg and100 mg.
Use in Children:
VIRECTA is not indicated for individuals below 18 years of age. there is no relevant indication for use in children.
Use in patients using other medicines:
With the exception of ritonavir for which co-administration with sildenafil is not advised a starting dose of 25mg should be considered in patients receiving concomitant treatment with CYP3A4 inhibitors.
In order to minimise the potential of developing postural hypotension in patients receiving alpha-blocker treatment patients should be stabilised on alpha-blocker therapy prior to initiating sildenafil treatment. In addition, initiation of sildenafil at a dose of 25mg should be
considered.

 


Adverse reactions were mild to moderate in nature and the incidence and severity increased with dose. In fixed dose studies, dyspepsia
and altered vision were more common at 100 mg than at lower doses. The most commonly reported adverse reactions were headache
and flushing.
Very common:≥ 1/10
Common: ≥ 1/100 and ˂1/10
Uncommon:≥ 1/1000 and ˂ 1/100
Rare:≥ 1/10000 and ˂ 1/1000
Very Rare:˂ 1/10000
Not Known: cannot be estimated from available data.
MedDRA System Organ Class:
Nervous system disorders
Very common: Headache. Common: Dizziness.
Eye disorders
Common: Altered vision (increased perception of light, blurred vision).Common: Chromatopsia (mild and transient, predominantly colour
tinge to vision).
Cardiac disorders
Common: Palpitations.
Vascular disorders
Very common:Flushing.
Respiratory, thoracic and mediastinal disorders.
Common:Nasal congestion.
Gastrointestinal disorders
Common:Dyspepsia.
There were reports of muscle aches when sildenafil was administered more frequently than the recommended dosing regimen.
The following adverse events have been uncommonly or rarely reported:
Immune system disorders: Hypersensitivity reactions.
Eye disorders: Eye pain, red eyes/bloodshot eyes.
Cardiac disorders: Tachycardia, Ventricular arrhythmia, Myocardial infarction, Unstable angina, Sudden cardiac death (see section 4).
Vascular disorders: Hypotension (see section 4), Hypertension, Epistaxis, syncope, cerebrovascular haemorrhage, transient ischaemic attack (see section 4).
Gastrointestinal disorders: Vomiting.
Skin, subcutaneous and soft tissue disorders: Skin rash.
Reproductive system and breast disorders: Prolonged erection, Priapism.
- Overdose:
In single dose volunteer studies of doses up to 800 mg, adverse reactions were similar to those seen at lower doses, but the incidence rates and severities were increased. Doses of 200 mg did not result in increased efficacy but the incidence of adverse reactions (headache, flushing, dizziness, dyspepsia, nasal congestion, altered vision) was increased.
In cases of overdose, standard supportive measures should be adopted as required. Renal dialysis is not expected to accelerate
clearance as sildenafil is highly bound to plasma proteins and not eliminated in the urine.


Keep out of the reach and sight of children.
Store below 30°C.
Store in the original package, in order to protect from moisture.


The active substance is Sildenafil Citrate.
The other ingredients in Tablet core are Microcrystalline cellulose, Dibasic Calcium Phosphate Anhydrous, Croscarmellose sodium , Colloidal anhydrous silica , Magnesium Stearate.
Film coat materials are lactose Monohydrate, Hypromellose, Titanium Dioxide, Triacetin, FD and C Blue 2.
 


Clear PVC/Aluminium blisters in cartons of 4 tablets.

-Middle East Distribution Co.Ltd. (MEDICO)
-Middle East Pharmaceutical Industries Co Ltd (Avalon Pharma)
Riyadh, KSA
Tel: +966(011)2653948
For any information about this medicinal product, please contact the Marketing authorization
Holder.


This leaflet was last approved in {02/2014}; version number {01}.
  نشرة الدواء تحت مراجعة الهيئة العامة للغذاء والدواء (اقرأ هذه النشرة بعناية قبل البدء في استخدام هذا المنتج لأنه يحتوي على معلومات مهمة لك)

علاج ضعف الإنتصاب عند الرجال ٬ والذي يعرف بعدم القدرة على تحقيق انتصاب القضيب أو المحافظة على الإنتصاب الكافي
لإتمام الممارسة الجنسية.
لا بد من وجود إثارة جنسية حتى يعمل فايريكتا بكفاءة .
- الخواص الصيدلانية :
- الخواص الديناميكية الدوائية:
الأدوية المستخدمة في علاج اعتلال الإنتصاب :
سيلدينافيل ھو علاج دوائي يتم تناوله عن طريق الفم لعلاج الإنتصاب في الوضع الطبيعي على سبيل المثال مع الإثارة الجنسية فهو
يحسن الإعتلال بوظيفة الإنتصاب عن طريق زيادة ضخ الدم إلى القضيب.
تضم الميكانيكية الفسيولوجية المسؤولة عن انتصاب القضيب انطلاق أكسيد النيتريك في العضو الذكري خلال الإثارة الجنسية
والذي يعمل بعد ذلك على تنشيط الإنزيم جولانيلات سيكلاز المسؤول عن زيادة معدلات سيكليك جوانيزين أحادي فوسفات الحلقي (c GMP) مما ينتج عن ذلك ارتخاء العضلات الملساء في العضو الذكري مما يسمح بتدفق الدم.

يعتبر سيلدينافيل مثبط فعال ل(c GMP) عن طريق وقف عمل الإنزيم فوسفودايستريز( ٥) في أنسجة العضو الذكري وهو المسؤول عن تكسير (c GMP) سيلدينافيل حيث لايوجد أي تأثير مباشر راخي للعضلات الملساء للعضو الذكري لكنه يحسن بكل فاعلية من تأثير أكسيد النيترك على ھذا النسيج عندما تنشط التفاعل بين أكسيد النيترك و(c GMP) كما يحدث في حالة الإثارة الجنسية تثبيط PDE 5 عن طريق سيلدينافيل مما يؤدي الى ارتفاع معدلات(c GMP) .لذلك فإن الإثارةالجنسية لازمة حتى يقوم سيلدينافيل بتأثيراته الدوائية الفعالة.

- بيانات السلامة قبل الإستخدام الإكلينيكي:
لم تظهر أي بيانات إكلينيكية أي خطر محدد على البشر تبعاً للدراسات التقليدية للأمن الدوائي ٬ زيادة الجرعة ٬ تسمم الإنجاب تسرطن ٬ تسمم الأجنة.

 

لا تستخدم فايريكتا إذا:
. كان لديك حساسية لسترات السيلدنافيل أو أي من المكونات الأخرى المدرجة في القسم ٦
إذا كنت غير متأكد ٬ تحدث إلى طبيبك أو الصيدلي قبل استخدام فايريكتا.
- نواھي الإستعمال :
الحساسية للمادة الفعالة أولأي من مكوناته .
بالمطابقة مع تأثيراته المعروفة على أكسيد النيتريك / جوانوزين أحادي الفوسفات الحلقي ٬ وجد سيلدينافيل أنه يساعد على زيادة تأثير
النترات الخافض لضغط الدم ولذلك يمنع ازدواجية العلاج بينه وبين أي مادة تعطي أكسيد النيتريك ( مثل الأميل النيترات) أو النيترات
في أي شكل .
لا يجب استعمال المستحضرات المستخدمة لعلاج ضعف الإنتصاب ومنهم سيلدينافيل مع الرجال الذين لا يسمح لهم بالممارسة الجنسية
(مثل المرضى الذين يعانون من أمراض القلب وأمراض الأوعية الدموية الخطيرة مثل الذبحة الصدرية الغير مستقرة وفشل عضلة
القلب) .
لا يجب استخدام فايريكتا مع المرضى الذين يعانون من فقد الإبصار ٬ھذا بعيداً عن كون ھذه الحالة على صلة بالتعرض السابق لمثبطات5 PDE.

لم يتم دراسة درجة الأمان لعقار سيلدينافيل في حالات معينة بعد وبالتالي لا ينصح باستخدامه في الحالات التالية :أمراض الكبد
۹٠ مم زئبقي) ٬التعرض حديثاً لحالة صدمة أو موت جزء من عضلة القلب ٬ مشاكل / الخطيرة ٬ انخفاض ضغط الدم ( ضغط الدم < ٥٠
الشبكية الوراثية المعروفة ٬ التهاب الشبكية الملون.
- التحذيرات والإحتياطات الخاصة للإستخدام:
يجب التحديد الدقيق للتاريخ المرضي وإجراء الفحص الطبي الدقيق لتشخيص خلل الإنتصاب ولمعرفة الأسباب الحقيقية المسببة لذلك قبل وصف العلاج الدوائي .
قبل البدء في أي علاج لضعف الإنتصاب لا بد من معرفة حالة القلب والدورة الدموية حيث أن سيلدينافيل ذو تأثير موسع للأوعية الدموية مما يؤدي إلى انخفاض طفيف أو متوسط في ضغط الدم: قبل وصف سيلدينافيل يجب أن يتأكد الطبيب جيداً من عدم وجود أي حالات قد تتأثر سلباً من التأثيرالموسع للأوعيه الدمويه خصوصاً مع الممارسة الجنسية .كالمرضى الذين لديهم قابلية عالية لتوسع الأوعية الدموية ومن ھؤلاء الذين لديهم إعاقة تدفق الدم من البطين الأيسر مثل ضيق الأورطي ٬تضخم عضلة القلب أو ھؤلاء الذين
لديهم أمراض نادرة مثل ضمور بعض الأجهزة مما يؤدي إلى إعتلال كبير في ضبط ضغط الدم.يتسبب الفايريكتا في زيادة التأثير الخافض لضغط الدم للنترات.
في حالات القلب الخطيرة مثل موت جزء من عضلة القلب ٬ والذبحة الصدرية غير المستقرة ٬ وموت القلب المفاجئ ٬ نزيف أوعية المخ ٬خفقان البطين ٬ارتفاع ضغط الدم: فقد تم تسجيل حالات انخفاض ضغط الدم عند استخدام الفايريكتا مع أغلب المرضى وليس الكل ممن يعانون من مشاكل بالقلب والأوعية الدموية وقد تم تسجيل كثير من الحالات قد حدثت أثناء او مباشرة بعد الممارسة الجنسية وقليل
من الحالات حدثت بعد استخدام الفايريكتا وبدون أداء ممارسة جنسية ٬من غير الممكن أن نتبين أسباب ھذه الحالات.
يجب أن تستخدم المستحضرات المستعملة لعلاج ضعف الإنتصاب ومن بينهم سيلدينافيل بحرص مع المرضى الذين لديهم تشوه خلقي للقضيب ( مثل الإنحراف ٬تليف العضو الذكري أو مع المرضى الذين لديهم حالات قد تؤدي إلى عدم الإنتصاب (مثل فقر الدم المنجلي ٬ اللوكيميا أو سرطان الدم).
لم يتم دراسة درجة الأمان ومقدار الفاعلية لدمج العلاج بعقار سيلدينافيل مع أي علاجات أخرى لحالة ضعف الانتصاب بعد وبالتالي لا ينصح باستخدامه مع أي علاجات أخرى.

تم تسجيل حالات مشاكل الإبصار و حالات متلازمة مع استخدام سيلدينافيل ومثبطات PDE5 الأخرى .لذا يجب أن ينصح المريض في حالة حدوث أي مشاكل مفاجئة بالبصر يجب أن يوقف استخدام فايريكتا و استشارة الطبيب فوراً.

لا ينصح بدمج العلاج بعقار سيلدينافيل مع عقار ريتونافير.
لا بد من توخي الحذر عند تعاطي سيلدينافيل للمرضى الذين يتعاطون مثبطات ألفا ٬ حيث أن الدمج قد يؤدي إلى انخفاض ملحوظ في ضغط الدم مع عدد قليل من الأشخاص الذين لديهم استعداد وھذا غالبا ما يحدث خلال ٤ ساعات من أخذ جرعة سيلدينافيل ولكي نقلل من احتمالية حدوث انخفاض ضغط الدم ٬ يجب أن يكون المريض خاضع لعلاج ثابت ومستقر بعقار مثبطات ألفا قبل بدء العلاج بعقار سيلدينافيل ٬ ينصح ببدء العلاج بجرعة من سيلدينافيل تركيز ٢٥ ملجم بالإضافة إلى ذلك يجب أن ينصح الطبيب المريض بما يجب أن يفعله في حالة حدوث أعراض انخفاض ضغط الدم.
أكدت الدراسات المعملية على الصفائح الدموية أن سيلدينافيل يزيد من تأثيرنيتروبروسايد الصوديوم كمضاد لتجمع الصفائح الدموية.لا توجد أي معلومات أمان عن وصف سيلدينافيل لمرضى السيولة أو القرحة المعدية النشطة. لذلك يجب ألا يوصف سيلدينافيل لهؤلاء المرضى إلا بعد التأكد من المخاطر المصاحبة .
لا يجب استخدام فايريكتا مع السيدات.
- التفاعلات مع المستحضرات الدوائية الأخرى والأشكال الأخرى للتفاعلات :
تأثيرالمستحضرات الدوائية الأخرى على سيلدينافيل:
من الدراسات المعملية:

يتم تمثيل سيلدينافيل أساساً بمساعدة السيتوكروم P450  CYP من النوع 3A4 بشكل رئيسي و 2C9 بشكل فرعي.

لذلك قد تقلل مثبطات ھذه الإنزيمات معدل التخلص من سيلدينافيل.

يعتبرعصير الجريب فروت مثبط ضعيف لعملية أيض CYP3A4 من جدار المعدة ويمكن أن يزيد معدلات سيلدينافيل في البلازما.

لم تؤثر الجرعات الواحدة من مضاد للحموضة ( ھيدروكسيد المغنيسيوم / الألومنيوم) على فاعلية سيلدينافيل .

على الرغم من أن الدراسات على التفاعلات العكسية لم تصل لكل المستحضرات الدوائية:فإن الدراسات أوضحت أنه لا تأثير للأدوية المصاحبة على الحرائك الدوائية للعقار سيلدينافيل عندما قسمت المجموعات كانت مثبطات CYP2C9  مثل تولبوتاميد، الوارفارين، الفينيتوين)، مثبطات CYP2D6 مثل مثبطات السيروتونين ٬ مضادات الاكتئاب ثلاثي الحلقات ) ٬ثيازايد ٬ مدرات البول ٬ مثبطات الإنزيم أنجيوتنسين ٬ معوقات قناة الكالسيوم ٬مثيلات مستقبلات بيتا أدرينال أو محفزي عملية الأيض عن طريق CYP450 مثل ريفامبيسين ٬ باربيتورات ) .

نيكورانديل ھو خليط من منشط لقناة البوتاسيوم والنترات. وبسبب وجود النترات في مكوناته فهو لديه تفاعلات خطيرة مع سيلدينافيل.
تأثيرسيلدينافيل على المستحضرات الدوائية:
في الدراسات المعملية :

يعتبر سيلدينافيل مثبط ضعيف للسيتوكروم P450 أنواعه  A2 ٬ 2C9 ٬2C19٬ 2F1 ٬ 2D6٬3A ومن غير المتوقع أن يغير ايريكتا معدل التخلص لأي من الأنواع لهذا الأنزيم.
لا توجد أي بيانات على تفاعلات سيلدينافيل مع مثبطات الفسفودي استيرايز مثل الثيوفيلين أو داي بيردامول .
في الدراسات العملية على البشر :
مطابق مع تأثيراته المعروفة على أكسيد النيتريك أظهر سيلدينافيل زيادة التأثير الخافض لضغط الدم الذي يسببه النيترات ودمج العلاج
بينه وبين أي مادة تعطي أكسيد النيتريك أو النيترات في أي صورة مرفوض.

لا يساعد سيلدينافيل ( ٥٠ ملجم) في زيادة وقت النزيف الذي يحدث بسبب حمض اسيتيل ساليسيليك ( ١٥٠ ملجم) .
لا يساعد سيلدينافيل ( ٥٠ ملجم) في زيادة تأثير الكحول المهبط لضغط الدم بين المتطوعين الأصحاء الذين لديهم متوسط أعلى
مستويات الكحول في الدم ۸٠ ملجم / ديسيلتر.
بالنسبة لأدوية ارتفاع ضغط الدم ٬ مدرات البول ٬ مثبطات بيتا ٬ مثيلات أنجيوتينسين (موسعة للأوعية الدموية والتي تعمل
مركزياً ٬التي تعوق قنوات الكالسيوم و التي تعوق المستقبلات الأدرينالية ٬ لم يظهر أي اختلاف في الأعراض الجانبية على المرضى
الذين تعاطوا سيلدينافيل مقارنة بهؤلاء الذين تعاطوا العلاج الوھمي . ففي دراسة متخصصة أجريت على التفاعلات الدوائية عندما تم
دمج سيلدينافيل ( ١٠٠ ملجم) مع الأملوديبين في مرضى الضغط المرتفع كان ھناك انخفاض في ضغط الدم السيستولي ۸ مم زئبقي
وانخفاض في ضغط الدم الدياستولي ۷ مم زئبقي. وھذه الإنخفاضات كانت بنفس النتائج عندما أعطى سيلدينافيل لمتطوعين أصحاء.

لا يؤثر سيلدينافيل ( ١٠٠ ملجم) على الحرائك الدوائية لمثبطات البروتياز ٬ ساكوينافير وريتونافير ٬ وكلهم يعملوا على CYP3A4.

 - الحمل والرضاعة الطبيعية
لا يجب استخدام فايريكتا للنساء.
لا توجد أي أعراض جانبية في الدراسات التناسلية على الفئران والأرانب بعد تناول الجرعة من سيلدينافيل عن طريق الفم.
- التأثيرات على القدرة على القيادة واستخدام الماكينات:
لا توجد دراسات على تأثير العقار على القدرة على القيادة واستخدام الماكينات.
أكدت الدراسات الإكلينيكية على وجود دوخة ٬ زغللة في الرؤية وھذا يستلزم بدوره من المرضى أن يكونوا على علم بكيفية تناول الفايريكتا قبل واستخدام الماكنة.

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للإستخدام عن طريق الفم.
للبالغين :
الجرعة الموصى بها ھي ٥٠ ملجم تؤخذ حسب الحاجة قبل ساعة تقريبا من حدوث الممارسة الجنسية.
تبعا للكفاءة المرجوة وقدرة تحمل الجسم قد تزيد الجرعة لغاية ١٠٠ ملجم أو تقل إلى ٢٥ ملجم كحد أدنى و أقصى جرعة مسموح بها
ھي تركيز ١٠٠ ملجم وتؤخذ مرة واحدة في اليوم. إن تعاطي عقار الفايريكتا أثناء الأكل ٬ يؤدي إلى تأخرمفعوله مقارنة في حالة أخذه
على معدة فارغة صائماً.
لكبار السن :
في حالة المرضى كبار السن:ينصح بعدم تغيير معدل الجرعة.

لمرضى الكلى:
۸٠ مل / - تستخدم الجرعة الموصى بها للبالغين مع مرضى الفشل الكلوي البسيط أو المتوسط ( معدل التخلص من كرياتينين = ۳٠
دقيقة ) حيث أن معدل سيلدينافيل يقل مع المرضى الذين يعانون من فشل كلوي خطير (معدل التخلص من كرياتينين أقل من ۳٠ مل /
دقيقة ) استخدام جرعة تركيز ٢٥ ملجم يكون تبعا للكفاءة المطلوبة وقدرة تحمل الجسم ٬ يمكن للجرعة أن تزيد حتى ٥٠ ملجم و ١٠٠
ملجم.
لمرضى الكبد :
حيث أن معدل التخلص من سيلدينافيل يقل مع المرضى الذين يعانون من اضطراب في وظائف الكبد (مثل تليف الكبد ) يجب إعطاء
جرعة بتركيز ٢٥ ملجم ويكون ذلك تبعاً للكفاءة المطلوبة وقدرة تحمل الجسم يمكن للجرعة أن تزيد حتى ٥٠ ملجم و ١٠٠ ملجم.
للأطفال :
لا يجب استخدام فايريكتا للأفراد تحت عمر ١۸ سنة . حيث لا يوجد أي سبب لإستخدامه مع الأطفال.
للمرضى الذين يتعاطون أدوية أخرى :
باستثناء عقار ريتونافير التي لا يوصى بتعاطيه مع سيلدينافيل ٬ فإنه لا بد من وصف جرعة بتركيز ٢٥ ملجم كبداية للمرضى الذين يخضعون لعلاج متلازم بمثبطات .CYP3A

لتقليل احتمالية حدوث ھبوط في ضغط الدم ٬ لا بد أن يكون المريض تحت علاج ثابت بعقار مثبطات ألفا قبل البدء بالعلاج بعقار
سيلدينافيل بالإضافة إلى ذلك لا بد من البدء بجرعة من سيلدينافيل بتركيز ٢٥ ملجم.

الأعراض الجانبية فقد تراوحت ما بين طفيف إلى متوسط من حيث الطبيعة ونسبة الحدوث ودرجة الخطورة وتزيد مع زيادة الجرعة في الدراسات علي الجرعة الثابتة ٬ عسر الهضم و زغللة الرؤية كانت أكثر حدوثاً مع تركيز ١٠٠ ملجم أكثر من مثليها مع جرعات أقل ٬ الأعراض الجانبية الأكثر شيوعاً كانت صداع وزيادة تدفق الدم.
١٠/ شائع جداً: ≥ ١
١٠/١ ˂ ٬١٠٠/ شائع: ≥ ١
١٠٠/١ ˃ ٬١٠٠٠/ غيرشائع: ≥ ١
١٠٠٠/١ ˃ ٬١٠٠٠٠/ نادر: ≥ ١
١٠٠٠٠/١ ˃ : نادر جداً
غير معروف: لا يمكن تقديره من البيانات المتاحة.
الاعراض الجانبية:
اعتلال الجهاز العصبي:
شائع جداً: صداع ٬ شائع: الدوخة.
اعتلال العين :
شائع : زيادة الحساسية للضوء (زغللة) ٬ شائع: خلل إدراك الألوان أو الرؤية الملونة (طفيف ومؤقت.
أمراض القلب:
شائع: خفقان.
أمراض الأوعية الدموية:
شائع جداً:زيادة تدفق الدم.
أمراض الجهاز التنفسي:
شائع: احتقان الأنف.
أمراض المعدة والأمعاء:
شائع: عسر الهضم.
ھناك تسجيلات عن آلام في العضلات في حالة تخطي سيلدينافيل أكثر من الجرعة الموصوفة.
سجلت الأعراض الجانبية التالية :
أعراض خاصة بالجهاز المناعي: تفاعلات حساسية.
أعراض خاصة بالعين: ألم في العين واحمرار في العينين.
أعراض خاصة بالقلب: زيادة سرعة ضربات القلب, والذبحة الصدرية غير المستقرة ٬موت القلب الفاجئ.
أعراض خاصة بالأوعية الدموية :انخفاض ضغط الدم ٬ ارتفاع ضغط الدم ٬ نزيف من الأنف ٬إغماء ٬ نزيف بأوعية المخ.
المعدة والأمعاء:قئ .
الجلد: طفح جلدي.
الجهاز التناسلي: طول مدة الإنتصاب ٬انتصاب دائم.
- زيادة الجرعة :
من خلال الجرعة الواحدة التي تم إعطائها للمتطوعين حتى تركيز ۸٠٠ ملجم:أكدت الدراسات على أن الأعراض الجانبية كانت مشابهة
لنفس الأعراض التي حدثت لمن تم إعطائهم جرعات أقل ولكن مع زيادة معدلات حدوث ودرجة الحدوث. لا تسبب الجرعات تركيز
٢٠٠ ملجم أي زيادة في الكفاءة ولكن زيادة في حدوث الأعراض الجانبية ( صداع ٬ تدفق ٬ دوخة ٬ عسر ھضم ٬ احتقان بالانف ٬ زغللة الرؤية).
في حالة زيادة الجرعات ٬ يجب اتباع المعايير القياسية ٬ الغسيل الكلوي غير مطلوب لزيادة الأيض وذلك لأن سيلدينافيل مرتبط جداً ببروتينات البلازما ولا يخرج عن طريق البول.

يحفظ بعيدا عن متناول أيدي الأطفال.
يخزن في درجة حرارة أقل من 30 درجة مئوية في العبوة الأصلية ٬ للحماية من الرطوبة.

يحتوي فايريكتا على:
المادة الفعالة في فايريكتا ھي سيلدنافيل ستيريت ما يعادل ٥٠ ملجم سيلدنافيل.
المواد الأخرى المضافة في قلب قرص فايريكتا ھي ميكرو كريستالين سليلوز ٬داي بيسك فوسفات الكالسيوم اللامائي ٬ كروسكارميلوز
الصوديوم ٬ السيليكا الغروية اللامائية ٬ مغنيسيوم ستيريت.
. مواد الغلاف لاكتوز مونوھيدرات ٬ ھيبروميلوز ٬ تيتانيوم داي اوكسيد ٬ ترياسيتين ٬ لون أزرق رقم ٢
 

كيف يبدوفايريكتا وما محتويات العلبة:
عبوة ٤ أقراص معبأة في بلستراتPVC/ رقائق المنيوم داخل كرتون.

الشرق الأوسط المحدودة للتوزيع (ميديكو)
الشرق الأوسط للصناعات الدوائية المحدودة (أفالون فارما)
الرياض ٬ المملكة العربية السعودية
+۹٦٦(٠١١) ت: ٢٦٥۳۹٤۸
للحصول على أي معلومات طبية عن ھذا المنتج ٬ يرجى الاتصال بحامل إذن التسويق.

02/2014 رقم الاصدار 01
 Read this leaflet carefully before you start using this product as it contains important information for you

Virecta 50 mg Film-Coated Tablet.

- List of active substances: Each unit of the product contains the following: Sildenafil citrate 71 mg per tablet (equivalent to 50 mg Sildenafil) List of Excipient: For a full list of excipients, see pharmaceutical particulars section.

Film-Coated Tablet.

- Virecta is an indicated in adult men with erectile dysfunction, which is the inability to achieve or maintain a penile erection sufficient for satisfactory sexual performance.
- In order for Virecta to be effective, sexual stimulation is required.


Posology and Method of Administration:
Posology
Use in adults
The recommended dose is 50 mg taken as needed approximately one hour before sexual activity. Based on efficacy and tolerability, the dose may be increased to 100 mg or decreased to 25 mg. The maximum recommended dose is 100 mg. The maximum recommended dosing frequency is once per day. If Virecta is taken with food, the onset of activity may be delayed compared to the fasted state (see section pharmacokinetics).
Special populations
Elderly patients
Dosage adjustments are not required in elderly patients (≥ 65 years old).
Patients with renal impairment
The dosing recommendations described in “Use in adults” apply to patients with mild to moderate renal impairment (creatinine clearance = 30-80 mL/min).
Since sildenafil clearance is reduced in patients with severe renal impairment (creatinine clearance < 30 mL/min) a 25 mg dose should be considered. Based on efficacy and tolerability, the dose may be increased step-wise to 50mg up to 100 mg as necessary.
Patients with hepatic impairment
Since sildenafil clearance is reduced in patients with hepatic impairment (e.g. cirrhosis) a 25 mg dose should be considered. Based on efficacy and tolerability, the dose may be increased step-wise to 50 mg up to 100 mg as necessary.
Paediatric population
Virecta is not indicated for individuals below 18 years of age.
Use in patients taking other medicinal products
With the exception of ritonavir for which co-administration with sildenafil is not advised (see section special warning and precautions for use ) a starting dose of 25mg should be considered in patients receiving concomitant treatment with CYP3A4 inhibitors (see section Interaction with other medicinal products and other forms of interaction).
In order to minimise the potential of developing postural hypotension in patients receiving alpha-blocker treatment patients should be stabilised on alpha-blocker therapy prior to initiating sildenafil treatment. In addition, initiation of sildenafil at a dose of 25mg should be considered (see sections special warnings and precautions for use and Interaction with other medicinal products and other forms of interaction).

Method of administration:
For oral use.


Hypersensitivity to the active substance or to any of the excipients listed in section F. Consistent with its known effects on the nitric oxide/cyclic guanosine monophosphate (cGMP) pathway (see section pharmacodynamic properties), sildenafil was shown to potentiate the hypotensive effects of nitrates, and its co-administration with nitric oxide donors (such as amyl nitrite) or nitrates in any form is therefore contraindicated. Agents for the treatment of erectile dysfunction, including sildenafil, should not be used in men for whom sexual activity is inadvisable (e.g. patients with severe cardiovascular disorders such as unstable angina or severe cardiac failure). Virecta is contraindicated in patients who have loss of vision in one eye because of non-arteritic anterior ischaemic optic neuropathy (NAION), regardless of whether this episode was in connection or not with previous PDE5 inhibitor exposure (Special warnings and precautions for use). The safety of sildenafil has not been studied in the following sub-groups of patients and its use is therefore contraindicated: severe hepatic impairment, hypotension (blood pressure < 90/50 mmHg), recent history of stroke or myocardial infarction and known hereditary degenerative retinal disorders such as retinitis pigmentosa (a minority of these patients have genetic disorders of retinal phosphodiesterases).

A medical history and physical examination should be undertaken to diagnose erectile dysfunction and determine potential underlying causes, before pharmacological treatment is considered.
Cardiovascular risk factors
Prior to initiating any treatment for erectile dysfunction, physicians should consider the cardiovascular status of their patients, since there is a degree of cardiac risk associated with sexual activity. Sildenafil has vasodilator properties, resulting in mild and transient decreases in blood pressure (see section pharmacodynamic properties). Prior to prescribing sildenafil, physicians should carefully consider whether their patients with certain underlying conditions could be adversely affected by such vasodilatory effects, especially in combination with sexual activity. Patients with increased susceptibility to vasodilators include those with left ventricular outflow obstruction (e.g., aortic stenosis, hypertrophic obstructive cardiomyopathy), or those with the rare syndrome of multiple system atrophy manifesting as severely impaired autonomic control of blood pressure.
Virecta potentiates the hypotensive effect of nitrates (see section contraindications).

Serious cardiovascular events, including myocardial infarction, unstable angina, sudden cardiac death, ventricular arrhythmia, cerebrovascular haemorrhage, transient ischaemic attack, hypertension and hypotension have been reported post-marketing in temporal association with the use of Virecta. Most, but not all, of these patients had pre-existing cardiovascular risk factors. Many events were reported to occur during or shortly after sexual intercourse and a few were reported to occur shortly after the use of Virecta without sexual activity. It is not possible to determine whether these events are related directly to these factors or to other factors.
Priapism
Agents for the treatment of erectile dysfunction, including sildenafil, should be used with caution in patients with anatomical deformation of the penis (such as angulation, cavernosal fibrosis or Peyronie's disease), or in patients who have conditions which may predispose them to priapism (such as sickle cell anaemia, multiple myeloma or leukaemia).
Concomitant use with other treatments for erectile dysfunction
The safety and efficacy of combinations of sildenafil with other treatments for erectile dysfunction have not been studied. Therefore the use of such combinations is not recommended.
Effects on vision
Cases of visual defects have been reported spontaneously in connection with the intake of sildenafil and other PDE5 inhibitors (see section undesirable effects). Cases of non-arteritic anterior ischaemic optic neuropathy, a rare condition, have been reported spontaneously and in an observational study in connection with the intake of sildenafil and other PDE5 inhibitors (see section undesirable effects). Patients should be advised that in the event of any sudden visual defect, they should stop taking Virecta and consult a physician immediately (see section contraindications).
Concomitant use with ritonavir
Co-administration of sildenafil with ritonavir is not advised (see section interaction with other medicinal products and other forms of interaction).
Concomitant use with alpha-blockers
Caution is advised when sildenafil is administered to patients taking an alpha-blocker, as the co-administration may lead to symptomatic hypotension in a few susceptible individuals (see section interaction with other medicinal products and other forms of interaction). This is most likely to occur within 4 hours post sildenafil dosing. In order to minimise the potential for developing postural hypotension, patients should be hemodynamically stable on alpha-blocker therapy prior to initiating sildenafil treatment. Initiation of sildenafil at a dose of 25 mg should be considered (see section posology and method of administration). In addition, physicians should advise patients what to do in the event of postural hypotensive symptoms.

Effect on bleeding
Studies with human platelets indicate that sildenafil potentiates the antiaggregatory effect of sodium nitroprusside in vitro. There is no safety information on the administration of sildenafil to patients with bleeding disorders or active peptic ulceration. Therefore sildenafil should be administered to these patients only after careful benefit-risk assessment.
Women
Virecta is not indicated for use by women.


Effects of other medicinal products on sildenafil
In vitro studies
Sildenafil metabolism is principally mediated by the cytochrome P450 (CYP) isoforms 3A4 (major route) and 2C9 (minor route). Therefore, inhibitors of these isoenzymes may reduce sildenafil clearance.
In vivo studies
Population pharmacokinetic analysis of clinical trial data indicated a reduction in sildenafil clearance when co-administered with CYP3A4 inhibitors (such as ketoconazole, erythromycin, cimetidine). Although no increased incidence of adverse events was observed in these patients, when sildenafil is administered concomitantly with CYP3A4 inhibitors, a starting dose of 25 mg should be considered.
Co-administration of the HIV protease inhibitor ritonavir, which is a highly potent P450 inhibitor, at steady state (500 mg twice daily) with sildenafil (100 mg single dose) resulted in a 300% (4-fold) increase in sildenafil Cmax and a 1,000% (11-fold) increase in sildenafil plasma AUC. At 24 hours, the plasma levels of sildenafil were still approximately 200ng/mL, compared to approximately 5ng/mL when sildenafil was administered alone. This is consistent with ritonavir's marked effects on a broad range of P450 substrates. Sildenafil had no effect on ritonavir pharmacokinetics. Based on these pharmacokinetic results co-administration of sildenafil with ritonavir is not advised (see section special warnings and precautions for use) and in any event the maximum dose of sildenafil should under no circumstances exceed 25 mg within 48 hours.
Co-administration of the HIV protease inhibitor saquinavir, a CYP3A4 inhibitor, at steady state (1200 mg three times a day) with sildenafil (100 mg single dose) resulted in a 140% increase in sildenafil Cmax and a 210% increase in sildenafil AUC. Sildenafil had no effect on saquinavir pharmacokinetics (see section posology and method of administration). Stronger CYP3A4 inhibitors such as ketoconazole and itraconazole would be expected to have greater effects.
When a single 100 mg dose of sildenafil was administered with erythromycin, a specific CYP3A4 inhibitor, at steady state (500 mg twice daily for 5 days), there was a 182% increase in sildenafil systemic exposure (AUC). In normal healthy male volunteers, there was no evidence of an effect of azithromycin (500 mg daily for 3 days) on the AUC, Cmax, tmax, elimination rate constant, or subsequent half-life of sildenafil or its principal circulating metabolite. Cimetidine (800 mg), a cytochrome P450 inhibitor and non-specific CYP3A4 inhibitor, caused a 56% increase in plasma sildenafil concentrations when co-administered with sildenafil (50 mg) to healthy volunteers.
Grapefruit juice is a weak inhibitor of CYP3A4 gut wall metabolism and may give rise to modest increases in plasma levels of sildenafil.
Single doses of antacid (magnesium hydroxide/aluminium hydroxide) did not affect the bioavailability of sildenafil.
Although specific interaction studies were not conducted for all medicinal products, population pharmacokinetic analysis showed no effect of concomitant treatment on sildenafil pharmacokinetics when grouped as CYP2C9 inhibitors (such as tolbutamide, warfarin, phenytoin), CYP2D6 inhibitors (such as selective serotonin reuptake inhibitors, tricyclic antidepressants), thiazide and related diuretics, loop and potassium sparing diuretics, angiotensin converting enzyme inhibitors, calcium channel blockers, beta-adrenoreceptor antagonists or inducers of CYP450 metabolism (such as rifampicin, barbiturates).
Nicorandil is a hybrid of potassium channel activator and nitrate. Due to the nitrate component it has the potential to result in a serious interaction with sildenafil.
Effects of sildenafil on other medicinal products
In vitro studies
Sildenafil is a weak inhibitor of the cytochrome P450 isoforms 1A2, 2C9, 2C19, 2D6, 2E1 and 3A4 (IC50 >150 μM). Given sildenafil peak plasma concentrations of approximately 1 μM after recommended doses, it is unlikely that VIRECTA will alter the clearance of substrates of these isoenzymes.
There are no data on the interaction of sildenafil and non-specific phosphodiesterase inhibitors such as theophylline or dipyridamole.
In vivo studies
Consistent with its known effects on the nitric oxide/cGMP pathway (see section pharmacodynamic properties), sildenafil was shown to potentiate the hypotensive effects of nitrates, and its co-administration with nitric oxide donors or nitrates in any form is therefore contraindicated (see section contraindications).
Concomitant administration of sildenafil to patients taking alpha-blocker therapy may lead to symptomatic hypotension in a few susceptible individuals. This is most likely to occur within 4 hours post sildenafil dosing (see sections Posology and method of administration and Special warnings and precautions for use). In three specific drug-drug interaction studies, the alpha-blocker doxazosin (4 mg and 8 mg) and sildenafil (25 mg, 50 mg, or 100 mg) were administered simultaneously to patients with benign prostatic hyperplasia (BPH) stabilized on doxazosin therapy. In these study populations, mean additional reductions of supine blood pressure of 7/7 mmHg, 9/5 mmHg, and 8/4 mmHg, and mean additional reductions of standing blood pressure of 6/6 mmHg, 11/4 mmHg, and 4/5 mmHg, respectively, were observed. When sildenafil and doxazosin were administered simultaneously to patients stabilized on doxazosin therapy, there were infrequent reports of patients who experienced symptomatic postural hypotension. These reports included dizziness and light-headedness, but not syncope.
No significant interactions were shown when sildenafil (50 mg) was co-administered with tolbutamide (250 mg) or warfarin (40 mg), both of which are metabolised by CYP2C9.
Sildenafil (50 mg) did not potentiate the increase in bleeding time caused by acetyl salicylic acid (150 mg).
Sildenafil (50 mg) did not potentiate the hypotensive effects of alcohol in healthy volunteers with mean maximum blood alcohol levels of 80 mg/dl.
Pooling of the following classes of antihypertensive medication; diuretics, beta-blockers, ACE inhibitors, angiotensin II antagonists, antihypertensive medicinal products (vasodilator and centrally-acting), adrenergic neurone blockers, calcium channel blockers and alpha-adrenoceptor blockers, showed no difference in the side effect profile in patients taking sildenafil compared to placebo treatment. In a specific interaction study, where sildenafil (100 mg) was co-administered with amlodipine in hypertensive patients, there was an additional reduction on supine systolic blood pressure of 8 mmHg. The corresponding additional reduction in supine diastolic blood pressure was 7 mmHg. These additional blood pressure reductions were of a similar magnitude to those seen when sildenafil was administered alone to healthy volunteers (see section pharmacodynamic properties).
Sildenafil (100 mg) did not affect the steady state pharmacokinetics of the HIV protease inhibitors, saquinavir and ritonavir, both of which are CYP3A4 substrates.


Virecta is not indicated for use by women.
There are no adequate and well-controlled studies in pregnant or breast-feeding women.
No relevant adverse effects were found in reproduction studies in rats and rabbits following oral administration of sildenafil.
There was no effect on sperm motility or morphology after single 100 mg oral doses of sildenafil in healthy volunteers.


No studies on the effects on the ability to drive and use machines have been performed.
As dizziness and altered vision were reported in clinical trials with sildenafil, patients should be aware of how they react to VIRECTA, before driving or operating machinery.


Summary of the safety profile
The safety profile of Virecta is based on 8691 patients who received the recommended dosing regimen in 67 placebo-controlled clinical studies. The most commonly reported adverse reactions in clinical studies among sildenafil treated patients were headache, flushing, dyspepsia, visual disorders, nasal congestion, dizziness and visual colour distortion.
Adverse reactions from post-marketing surveillance has been gathered covering an estimated period >9 years. Because not all adverse reactions are reported to the Marketing Authorisation Holder and included in the safety database, the frequencies of these reactions cannot be reliably determined.
Tabulated list of adverse reactions
In the table below all medically important adverse reactions, which occurred in clinical trials at an incidence greater than placebo are listed by system organ class and frequency (very common (≥1/10), common (≥1/100 to <1/10), uncommon (≥1/1,000 to <1/100), rare (≥1/10,000 to, 1/1,000).
In addition, the frequency of medically important adverse reactions reported from post-marketing experience is included as not known.
Within each frequency grouping, undesirable effects are presented in order of decreasing seriousness.
Table 1: Medically important adverse reactions reported at an incidence greater than placebo in controlled clinical studies and medically important adverse reactions reported through post-marketing surveillance 

-TO REPORT ANY SIDE EFFECT(S):
Saudi Arabia:
The National Pharmacovigilance and Drug Safety Centre (NPC)
o Fax: +966-11-205-7662
o Call NPC at +966-11-2038222, Exts: 2317-2356-2353-2354-2334-2340.
o Toll free phone: 8002490000
o E-mail: npc.drug@sfda.gov.sa
o Website: www.sfda.gov.sa/npc
Other GCC States:
- Please contact the relevant competent authority

 


In single dose volunteer studies of doses up to 800 mg, adverse reactions were similar to those seen at lower doses, but the incidence rates and severities were increased. Doses of 200 mg did not result in increased efficacy but the incidence of adverse reactions (headache, flushing, dizziness, dyspepsia, nasal congestion, altered vision) was increased.
In cases of overdose, standard supportive measures should be adopted as required. Renal dialysis is not expected to accelerate clearance as sildenafil is highly bound to plasma proteins and not eliminated in the urine.


Pharmacotherapeutic group: Urologicals; Drugs used in erectile dysfunction. ATC Code: G04B E03.
Mechanism of action
Sildenafil is an oral therapy for erectile dysfunction. In the natural setting, i.e. with sexual stimulation, it restores impaired erectile function by increasing blood flow to the penis.
The physiological mechanism responsible for erection of the penis involves the release of nitric oxide (NO) in the corpus cavernosum during sexual stimulation. Nitric oxide then activates the enzyme guanylate cyclase, which results in increased levels of cyclic guanosine monophosphate (cGMP), producing smooth muscle relaxation in the corpus cavernosum and allowing inflow of blood.
Sildenafil is a potent and selective inhibitor of cGMP specific phosphodiesterase type 5(PDE5) in the corpus cavernosum, where PDE5 is responsible for degradation of cGMP. Sildenafil has a peripheral site of action on erections. Sildenafil has no direct relaxant effect on isolated human corpus cavernosum but potently enhances the relaxant effect of NO on this tissue. When the NO/cGMP pathway is activated, as occurs with sexual stimulation, inhibition of PDE5 by sildenafil results in increased corpus cavernosum levels of cGMP. Therefore sexual stimulation is required in order for sildenafil to produce its intended beneficial pharmacological effects.

Studies in vitro have shown that sildenafil is selective for PDE5, which is involved in the erection process. Its effect is more potent on PDE5 than on other known phosphodiesterases.
There is a 10-fold selectivity over PDE6 which is involved in the phototransduction pathway in the retina. At maximum recommended doses, there is an 80-fold selectivity over PDE1, and over 700-fold over PDE 2, 3, 4, 7, 8, 9, 10 and 11. In particular, sildenafil has greater than 4,000-fold selectivity for PDE5 over PDE3, the cAMP-specific phosphodiesterase isoform involved in the control of cardiac contractility.
Clinical efficacy and safety
Two clinical studies were specifically designed to assess the time window after dosing during which sildenafil could produce an erection in response to sexual stimulation. In a penile plethysmography (RigiScan) study of fasted patients, the median time to onset for those who obtained erections of 60% rigidity (sufficient for sexual intercourse) was 25 minutes (range 12-37 minutes) on sildenafil. In a separate RigiScan study, sildenafil was still able to produce an erection in response to sexual stimulation 4-5 hours post-dose.
Sildenafil causes mild and transient decreases in blood pressure which, in the majority of cases, do not translate into clinical effects. The mean maximum decreases in supine systolic blood pressure following 100 mg oral dosing of sildenafil was 8.4 mmHg. The corresponding change in supine diastolic blood pressure was 5.5 mmHg. These decreases in blood pressure are consistent with the vasodilatory effects of sildenafil, probably due to increased cGMP levels in vascular smooth muscle. Single oral doses of sildenafil up to 100 mg in healthy volunteers produced no clinically relevant effects on ECG.
In a study of the hemodynamic effects of a single oral 100 mg dose of sildenafil in 14 patients with severe coronary artery disease (CAD) (>70% stenosis of at least one coronary artery), the mean resting systolic and diastolic blood pressures decreased by 7% and 6% respectively compared to baseline. Mean pulmonary systolic blood pressure decreased by 9%. Sildenafil showed no effect on cardiac output, and did not impair blood flow through the stenosed coronary arteries.
A double-blind, placebo-controlled exercise stress trial evaluated 144 patients with erectile dysfunction and chronic stable angina who regularly received anti-anginal medicinal products (except nitrates). The results demonstrated no clinically relevant differences between sildenafil and placebo in time to limiting angina.
Mild and transient differences in colour discrimination (blue/green) were detected in some subjects using the Farnsworth-Munsell 100 hue test at 1 hour following a 100 mg dose, with no effects evident after 2 hours post-dose. The postulated mechanism for this change in colour discrimination is related to inhibition of PDE6, which is involved in the phototransduction cascade of the retina. Sildenafil has no effect on visual acuity or contrast sensitivity. In a small size placebo-controlled study of patients with documented early age-related macular degeneration (n=9), sildenafil (single dose, 100 mg) demonstrated no significant changes in the visual tests conducted (visual acuity, Amsler grid, colour discrimination simulated traffic light, Humphrey perimeter and photostress).
There was no effect on sperm motility or morphology after single 100 mg oral doses of
Sildenafil in healthy volunteers (see section fertility, pregnancy and lactation).
Further information on clinical trials
In clinical trials sildenafil was administered to more than 8000 patients aged 19-87. The following patient groups were represented: elderly (19.9%), patients with hypertension (30.9%), diabetes mellitus (20.3%), ischaemic heart disease (5.8%), hyperlipidaemia (19.8%), spinal cord injury (0.6%), depression (5.2%), transurethral resection of the prostate (3.7%), radical prostatectomy (3.3%). The following groups were not well represented or excluded from clinical trials: patients with pelvic surgery, patients post-radiotherapy, patients with severe renal or hepatic impairment and patients with certain cardiovascular conditions (see section Contraindications).
In fixed dose studies, the proportions of patients reporting that treatment improved their erections were 62% (25 mg), 74% (50 mg) and 82% (100 mg) compared to 25% on placebo. In controlled clinical trials, the discontinuation rate due to sildenafil was low and similar to placebo.
Across all trials, the proportion of patients reporting improvement on sildenafil were as follows: psychogenic erectile dysfunction (84%), mixed erectile dysfunction (77%), organic erectile dysfunction (68%), elderly (67%), diabetes mellitus (59%), ischaemic heart disease (69%), hypertension (68%), TURP (61%), radical prostatectomy (43%), spinal cord injury (83%), depression (75%). The safety and efficacy of sildenafil was maintained in long term studies.
Paediatric population
The European Medicines Agency has waived the obligation to submit the results of studies with VIRECTA in all subsets of the paediatric population for the treatment of erectile dysfunction. See section Posology and method of administration for information on
paediatric use


Absorption
- Sildenafil is rapidly absorbed. Maximum observed plasma concentrations are reached within 30 to 120 minutes (median 60 minutes) of oral dosing in the fasted state. The mean absolute oral bioavailability is 41% (range 25-63%). After oral dosing of sildenafil AUC and Cmax increase in proportion with dose over the recommended dose range (25-100 mg).
- When sildenafil is taken with food, the rate of absorption is reduced with a mean delay in tmax of 60 minutes and a mean reduction in Cmax of 29%.
Distribution
-The mean steady state volume of distribution (Vd) for sildenafil is 105 l, indicating distribution into the tissues. After a single oral dose of 100 mg, the mean maximum total plasma concentration of sildenafil is approximately 440 ng/mL (CV 40%). Since sildenafil (and its major circulating N-desmethyl metabolite) is 96% bound to plasma proteins, this results in the mean maximum free plasma concentration for sildenafil of 18 ng/mL (38 nM). Protein binding is independent of total drug concentrations.
- In healthy volunteers receiving sildenafil (100 mg single dose), less than 0.0002% (average 188 ng) of the administered dose was present in ejaculate 90 minutes after dosing.
- Biotransformation
- Sildenafil is cleared predominantly by the CYP3A4 (major route) and CYP2C9 (minor route) hepatic microsomal isoenzymes. The major circulating metabolite results from N-demethylation of sildenafil. This metabolite has a phosphodiesterase selectivity profile similar to sildenafil and an in vitro potency for PDE5 approximately 50% that of the parent drug. Plasma concentrations of this metabolite are approximately 40% of those seen for sildenafil. The N-desmethyl metabolite is further metabolised, with a terminal half-life of approximately
4 h.
- Elimination
- The total body clearance of sildenafil is 41 L/h with a resultant terminal phase half-life of 3-5 h. After either oral or intravenous administration, sildenafil is excreted as metabolites predominantly in the faeces (approximately 80% of administered oral dose) and to a lesser extent in the urine (approximately 13% of administered oral dose).
- Pharmacokinetics in special patient groups
- Elderly
- Healthy elderly volunteers (65 years or over) had a reduced clearance of sildenafil, resulting in approximately 90% higher plasma concentrations of sildenafil and the active N-desmethyl metabolite compared to those seen in healthy younger volunteers (18-45 years). Due to age-differences in plasma protein binding, the corresponding increase in free sildenafil plasma concentration was approximately 40%.
- Renal insufficiency
- In volunteers with mild to moderate renal impairment (creatinine clearance = 30-80 mL/min), the pharmacokinetics of sildenafil were not altered after receiving a 50 mg single oral dose. The mean AUC and Cmax of the N-desmethyl metabolite increased 126% and 73% respectively, compared to age-matched volunteers with no renal impairment. However, due to high inter-subject variability, these differences were not statistically significant. In volunteers with severe renal impairment (creatinine clearance < 30 mL/min), sildenafil clearance was reduced, resulting in mean increases in AUC and Cmax of 100% and 88% respectively compared to age-matched volunteers with no renal impairment. In addition, N-desmethyl metabolite AUC and Cmax values were significantly increased 79% and 200% respectively.
- Hepatic insufficiency
- In volunteers with mild to moderate hepatic cirrhosis (Child-Pugh A and B) sildenafil clearance was reduced, resulting in increases in AUC (84%) and Cmax (47%) compared to age-matched volunteers with no hepatic impairment. The pharmacokinetics of sildenafil in patients with severely impaired hepatic function have not been studied.


Non-clinical data revealed no special hazard for humans based on conventional studies of safety pharmacology, repeated dose toxicity, genotoxicity, carcinogenic potential, and toxicity to reproduction and development.


Microcrystalline cellulose
Dibasic Calcium Phosphate Anhydrous
Croscarmellose sodium
Colloidal anhydrous silica
Magnesium Stearate
lactose Monohydrate-Hypromellose-Titanium Dioxide-Triacetin-FD and C Blue 2(Opadry II 32K10886 blue)


None known.


The shelf life is 2 years.

Store below 30°C.


Clear PVC/PVDC/Alu Blister.
Pack size: 4 Film-Coated Tablets.


No special requirements.


MEDICO (Middle East Distribution Co.Ltd.) Riyadh, KSA, Tel: +966(011)2653948

02/2014
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