Relief of moderate to severe pain.
Premedication.
Obstetric analgesia.
Enhancement of analgesia

Adults.
For moderate or severe pain.
Normal single dose (usually not to be repeated more often than 4 hourly)
By intramuscular or subcutaneous injection 25 - 100 mg.
By slow intravenous injection 25 - 50 mg.
For obstetric analgesia.
By intramuscular or subcutaneous injection repeated 1 - 3 hours later. 50 - 100 mg.
Maximum of 400mg in 24 hours.

As a premedication.
By intramuscular injection one hour prior to the operation. 50 - 100mg
For the enhancement of analgesia.
By slow intravenous injection. 10 - 25mg as required.
Elderly or debilitated patients.
Initial doses should not exceed 25mg as this group of patients may be specially sensitive to the central depressant effect of the drug.
Children
For moderate or severe pain.
By intramuscular injection. 0.5 - 2 mg per Kg of body weight.
As a premedication.
By intramuscular injection one hour prior to the operation. 1 - 2 mg per Kg of body weight.

Respiratory depression, obstructive airways disease or acute asthma. It should not be administered to patients with severe renal impairment or severe hepatic impairment. Should be avoided in patients with acute alcoholism, delirium tremens, raised intracranial pressure or in those with convulsive states such as status epilepticus. It should not be administered to patients receiving monoamine oxidase inhibitors or moclobemide, or within two weeks of their withdrawal. Pethidine should not be administered to patients receiving ritonavir or selegiline. Not to be given to patients with a history of hypersensitivity or idiosyncratic response to the drug or its excipients. Use of pethidine should be avoided in patients with supraventricular tachycardia. Use of pethidine in patients with phaechromocytoma may result in hypertensive crisis. Use of pethidine should be avoided in patients with diabetic acidosis where there is danger of coma.

Repeated use may result in dependence of the morphine type.
The use of pethidine should be avoided in patients with head injuries where administration may affect both the respiratory function and pupillary responses required for neurological assessment.
Pethidine should be avoided in patients with low respiratory reserve due to the respiratory effects of the drug.
Pethidine should only be given with caution and in reduced doses to neonates, premature infants, patients who are elderly or debilitated or those with impaired hepatic or renal function. All of these patient groups may experience increased or prolonged effects of the product.
Pethidine should be used with caution in patients with shock, hypothyrodism, adreno-corticol insufficiency and a history of convulsive disorders.
Although less spasmogenic than morphine, pethidine may precipitate spasm of the ureter or Sphincter of Oddi. Subsequently it should be used with caution in patients with prostatic hypertrophy and biliary tract disorders including those with pain secondary to gallbladder pathology.
Pethidine should be used with caution in patients with existing hypotension as it may reduce the blood pressure further. In addition it should be avoided in patients with severe inflammatory bowel disease due to its effects on the gastrointestinal tract where it may precipitate toxic megacolon.

Pethidine should not be administered to patients receiving monoamine oxidase inhibitors or moclobemide or within two weeks of their withdrawal (see Section 4.3).
Patients receiving selegiline should not be given pethidine as hyperpyerxia and CNS toxicity may result. Plasma concentration of pethidine may be decreased by concomitant administration of ritonavir, however levels of norpethidine (a toxic metabolite) may rise. Concomitant administration of ritonavir and pethidine should be avoided (see Section 4.3).
Rasagiline should not be given with pethidine as there is risk of CNS toxicity, its use should be avoided for two weeks after taking rasagiline.
Cimetidine potentiates the effect of pethidine.
Duloxetine when given with pethidine can increase the serotonergic effects.
The effects of pethidine may also be potentiated by concurrent administration with other CNS depressants including anaesthetics, anxiolytics, hypnotics, and alcohol (see Section 4.3).
Administration of phenytoin may cause the increase in hepatic metabolism of pethidine and subsequently increased levels of norpethidine (a toxic metabolite).
Concomitant administration with phenothiazines may induce severe hypotension.

 

There is inadequate evidence of safety in human pregnancy, but the drug has been in widely used for many years without apparent ill consequence. Animal studies have not shown any hazard.
As with all drugs during pregnancy care should be taken in assessing the risk to benefit ratio. Pethidine crosses the placental barrier and is excreted in breast milk. This should be taken into account when considering its use in patients during pregnancy or breast feeding.
Administration during labour may cause respiratory depression in the new-born infant.

Pethidine may cause drowsiness. If affected patients should not drive or operate machinery.
This medicine can impair cognitive function and can affect a patient’s ability to drive safely. This class of medicine is in the list of drugs included in regulations under 5a of the Road Traffic Act 1988. When prescribing this medicine, patients should be told:
• The medicine is likely to affect your ability to drive
• Do not drive until you know how the medicine affects you
• It is an offence to drive while under the influence of this medicine
• However, you would not be committing an offence (called ‘statutory defence’) if:
o The medicine has been prescribed to treat a medical or dental problem and
o You have taken it according to the instructions given by the prescriber and in the information provided with the medicine and
o It was not affecting your ability to drive safely

 

General hypersensitivity reactions occur rarely.
Mild euphoria may occur and CNS excitation has been reported in some patients. Following administration of pethidine, dizziness, fainting, drowsiness, weakness, hallucinations, dysphoria, mood changes, vertigo, sweating and headache have been reported. Dependence may occur as a result of continued use.
Pethidine may obtund or abolish the corneal reflex and cause pupillary constriction. In addition miosis has been reported.
Other undesirable effects include hypotension, hypertension, dry mouth, facial flushing, bradycardia, tachycardia, palpitations, vasodilatation and postural hypotension.
Administration of pethidine may cause respiratory depression
Nausea, vomiting and constipation have all been reported following administration of pethidine.
Rashes, urticaria and pruritus may occur due to histamine release.
Ureteric or biliary spasm may be experienced, as may difficulty with micturition.
There have been reports of decreased libido or potency.
Local reactions at the injection site may be experienced. These include induration and local irritation.
The development of hypothermia has been reported.
- To reports any side effect(s):
• Saudi Arabia:
The National Pharmacovigilance and Drug Safety Centre (NPC)

• Fax: +966-11-205-7662
• Call NPC at +966-11-2038222, Exts: 2317-2356-2353-2354-2334-2340.
• Toll free phone: 8002490000
• E-mail: npc.drug@sfda.gov.sa
• Website: www.sfda.gov.sa/npc

Symptoms
Incoordination, tremors and convulsions followed by respiratory depression and coma.
Treatment
If respiration is dangerously depressed the use of naloxone is recommended. Artificial respiration may be necessary.
If signs of CNS toxicity are exhibited the use of pethidine should be discontinued. Respiratory support and, if necessary, anticonvulsive therapy should be provided.

Pethidine is a narcotic analgesic with similar actions to morphine.

Pethidine is extensively distributed throughout the body with a volume of distribution of 200 - 300L.
It is 40 - 65% plasma bound and can cross the placenta.
70% of a dose is excreted in the urine in 24 hours.
5 - 30% is unchanged depending on the pH of the urine.

No additional pre-clinical data of relevance to the prescriber.

Sodium Hydroxide BP may be added to adjust the pH.
Water for Injection BP

Pethidine is incompatible with barbiturate salts and with other drugs including aminophylline, heparin sodium, methicillin sodium, morphine sulphate, nitrofurantoin sodium, phenytoin sodium, sulphadiazine sodium, sodium iodide, sulphafurazole diethanolamine. Incompatibility has also been observed between pethidine hydrochloride and acyclovir sodium, imipenem, frusemide and idarubicin.
Colour changes or precipitation have been observed on mixing pethidine with the following drugs, minocycline hydrochloride, tetracycline hydrochloride, cefoperazone sodium, mezlocillin sodium, nafcillin sodium and liposomal doxorubicin hydrochloride.

 

36 months.

Store below 25°. Store in airtight container. Protect from light.

1ml and 2ml in colourless Type 1 neutral glass ampoules. Fusion sealed. Packed in cartons of 10 ampoules.

None stated.