Indications & Uses
Pethidine-R is indicated for:
Pharmacology
Pethidine is a synthetic opioid analgesic belonging to the phenylpiperidine class, and it works mainly by acting on mu-opioid receptors. As with most opioid analgesics, it mimics the body's own natural opioids, activating opioid receptors in both the central and peripheral nervous systems. This action reduces the release of certain neurotransmitters and dampens the activity of nerve cells on the receiving end of pain signals in the spinal cord, which in turn blocks the pain impulses from getting through.
Dosage Reference
Reference Information Only
Dosages shown are general references from official sources. Always consult your doctor or pharmacist for personalized dosing.
Adults:
Analgesia
Adjust the dose of Pethidine Hydrochloride to the severity of the pain and how the patient responds. It also depends on the patient's profile, for example age, weight, sex and previous exposure to narcotics. The usual doses are 25 to 100 mg by IM (preferred) or S.C. injection every 3 to 4 hours, or 25 to 50 mg by slow IV injection every 3 to 4 hours. The usual dose by the IV route is 200 mg/day. Give intravenous injections very slowly, preferably as a diluted solution.
For a continuous intravenous infusion, establish adequate analgesia before starting the infusion. The recommended initial intravenous infusion rate is 0.3 mg/kg/hr. Clinical experience suggests that patients with normal renal function who receive more than 1000 mg/24 hrs of pethidine are at particular risk of pethidine associated neurotoxicity (PAN). Patients receiving over 800 mg/24 hrs should usually be monitored for early signs of norpethidine toxicity.
Obstetric Analgesia
Give 50 to 100 mg by IM (preferred) or S.C. injection once the pain becomes regular. If necessary, repeat 3 to 4 times at intervals of one to three hours. The maximum is 4 doses in 24 hours.
Anaesthesia Adjunct
As premedication, give 50 to 100 mg intramuscularly (preferred) or subcutaneously, thirty to ninety minutes before anaesthesia. As an adjunct during anaesthesia, give it intravenously by repeated slow injection of fractional doses of a solution diluted to 10 mg per mL. The dose by this route should not exceed 25 to 50 mg. Titrate the dose to the patient's needs, depending on the premedication given, the type of anaesthesia, and the nature and duration of the surgical procedure.
Patient-Controlled Analgesia
With patient-controlled analgesia (PCA), the patient judges their own level of pain and so titrates the amount of pethidine they need for adequate pain control against sedation and other side effects. Establish adequate analgesia before starting PCA. The doses and time intervals are preset in a microprocessor-controlled infusion pump. When the patient feels pain, they press a button and a dose of pethidine is given intravenously. If the button is pressed before the preset time interval (the lockout interval) has passed, no extra drug is given.
For adults, demand doses of 5 mg to a maximum of 20 mg pethidine have been given by PCA, with a lockout interval of 6 to 20 minutes. Some syringe pumps also deliver a background continuous infusion of pethidine at a basal rate along with the self-administered dose. Some PCA pumps let you preset a maximum dose over a defined period, to avoid overdosage. Set the demand dose and lockout interval according to the patient's analgesic requirements. Patients on a background infusion should generally get a smaller demand dose than equivalent patients on a demand dose only.
Clinical experience suggests that patients with normal renal function who receive more than 1000 mg/24hrs of pethidine are at particular risk of developing pethidine associated neurotoxicity (PAN). Patients receiving over 800 mg/24hrs should usually be monitored for early signs of norpethidine toxicity. Pethidine-associated neurotoxicity is dose related, so pethidine should not be used for longer than 24 to 36 hours.
Paediatric Dose
For analgesia, give 0.5 to 2 mg per kg of body weight intramuscularly (preferred) or subcutaneously, not to exceed 100 mg, every three to four hours as needed. For preoperative use, give 1 to 2 mg per kg of body weight intramuscularly (preferred) or subcutaneously, not to exceed 100 mg, thirty to ninety minutes before anaesthesia.
Neonates: pethidine is excreted and metabolised more slowly in the neonate than in adults. Safety has not been established in neonates, and because there is no data, no dosage regimen can be recommended.
Side Effects
Central Nervous System: Patients commonly notice lightheadedness, dizziness, sedation, and sweating, along with occasional bizarre sensations, disorientation, hallucinations, or psychosis. These effects tend to stand out more in patients who are up and about, or in those whose pain is not severe, and lying down after a slightly reduced dose often brings relief. Gastrointestinal: Nausea, vomiting, and constipation may also occur.
Cautions & Contraindications
Warnings & Precautions
Serious or life-threatening reactions such as respiratory depression, coma, and convulsions, possibly due to elevated levels of norpethidine, and hypotension have been associated with the use of pethidine. Because of this, the recommendations in the Warnings and Precautions sections should be carefully observed. Pethidine should be used with caution in patients taking other CNS depressant drugs such as hypnotics and sedatives including barbiturates and benzodiazepines, phenothiazines and other tranquillisers, anaesthetics, alcohol, and antidepressants. Patients with severe pain may tolerate very high doses of pethidine but may show respiratory depression should their pain suddenly subside. Elderly patients show increased sensitivity to opioids compared with younger patients. Reduced liver function, reduced kidney function, and reduced plasma protein binding may contribute to the higher plasma levels found in elderly patients. Since pethidine is broken down in the liver and removed via the kidneys, the possibility of the toxic metabolite norpethidine building up should be considered in patients with liver and/or kidney impairment. Reduced cardiac output may lead to reduced blood flow to the liver and reduced breakdown of pethidine, leading to a buildup of pethidine with possible toxic effects. Pethidine may cause a temporary rise in blood pressure, systemic vascular resistance, and heart rate. For this reason, it is not recommended for pain relief in cardiac infarction. In patients with phaeochromocytoma, pethidine may bring on a hypertensive crisis. In a person who is physically dependent on opioids, giving the usual dose of an opioid antagonist will bring on an acute withdrawal syndrome. How severe this is depends on the degree of physical dependence and the dose of antagonist given. Using opioid antagonists in such individuals should be avoided if possible. If an opioid antagonist must be used to treat serious respiratory depression in a physically dependent patient, it should be given with extreme care, using only 10 to 20 percent of the usual starting dose. Pethidine may worsen existing convulsions in patients with convulsive disorders. If the dose is raised well above the recommended level because tolerance has developed, convulsions may occur even in people with no history of convulsive disorders. In eclampsia, combining pethidine with phenothiazines has been reported to bring back seizures rather than stop them. For this reason, using pethidine in eclampsia and pre-eclampsia is not recommended. Although pethidine is commonly used for pain relief in obstetrics, it is known to cross the placenta and may cause depression in the newborn, including respiratory depression. An opioid antagonist such as naloxone may be needed to reverse this. In newborns, pethidine is removed and broken down at a much slower rate than in adults. Orthostatic hypotension has been reported in ambulatory patients given pethidine. Pethidine should be given with caution, and the starting dose should be reduced, in patients with hypothyroidism or Addison's disease. Pethidine should be used with caution in patients with prostatic hypertrophy or urethral stricture. Since opiate agonists may raise blood sugar, this effect should be kept in mind when diabetic patients need pethidine. There are conflicting reports on how pethidine affects the eye. Some reports say pethidine and related drugs cause the pupils to narrow, while others say they tend to cause the pupils to widen or show no change at all. Until this effect is better understood, eye pressure should be monitored in glaucoma patients given pethidine.
Contraindications
Pethidine Hydrochloride should not be given to anyone who is hypersensitive to pethidine. It is also contraindicated in respiratory depression, or where respiratory reserve is depleted (acute bronchial asthma, chronic airway disease, severe emphysema, severe chronic bronchitis, kyphoscoliosis). Head injury, raised intracranial pressure and brain tumour are contraindications too. Apart from introducing monitoring and diagnostic problems, hypercapnia linked to respiratory depression can itself raise intracranial pressure. Cardiac arrhythmias, especially supraventricular tachycardias, and cor pulmonale are also contraindications. Pethidine has a vagolytic action and may produce a significant increase in the ventricular response rate. Pethidine must not be used with monoamine oxidase inhibitors (MAOIs), including selegiline, or within two weeks of stopping them. This combination has caused hypotension, hypertension, excitation, rigidity, hyperpyrexia and/or convulsions, and in some cases deaths have been reported. Concurrent use should be avoided. Pre-eclampsia and eclampsia are contraindications. So are convulsive states such as status epilepticus, tetanus and strychnine poisoning, because pethidine stimulates the spinal cord. Do not use it in diabetic acidosis where there is a danger of coma, or in acute alcoholism or delirium tremens. Severe liver disease and incipient hepatic encephalopathy are contraindications as well. It is also contraindicated in patients with a low platelet count, coagulation disorders, or those receiving anticoagulant treatment. Continuous intravenous infusion: giving pethidine by continuous intravenous infusion to patients with renal impairment is contraindicated. Patient-controlled analgesia: giving pethidine by patient-controlled analgesia (PCA) to young children and to adults with poor cognitive function is contraindicated. Giving it by PCA to patients with renal impairment is also contraindicated.
Pregnancy & Breastfeeding
Pregnancy Category C. Opioids can cause respiratory depression in a newborn, so pethidine should only be used during labour if the expected benefit to the mother is judged to outweigh the risk to the foetus. No animal reproduction studies have been done with pethidine hydrochloride, and its safety when used earlier in pregnancy, before labour, has not been established in terms of effects on foetal development.
Breastfeeding: Pethidine passes into breast milk, but data on how much is excreted or at what concentration are not currently available, so the clinical significance for a breastfed infant is not yet known. For this reason, its use is not recommended in nursing mothers.
⚠️ Talk to your doctor before taking any medicine during pregnancy or while breastfeeding.
Use in Special Populations
Geriatric patients (over 70 years): the dose should be cut to half the normal adult dose.
Liver impairment: the dose should be reduced, or the gap between doses made longer, or both.
Renal impairment: norpethidine can build up in patients with renal failure, so take care when giving pethidine to these patients, especially over long periods. For this reason, a lower dose or a longer interval between doses is recommended.
Overdose
In an overdose of pethidine hydrochloride, the signs include CNS and respiratory depression, dilated pupils (mydriasis), a slow heart rate (bradycardia) and pulmonary oedema. Chronic tremor, CNS excitability and seizures can also occur.
Treatment is symptomatic. Naloxone can be used to reverse the opioid effects, but don't give naloxone for seizures caused by pethidine.
⚠️ In an emergency call 999 or go to the nearest hospital emergency department.
Storage
Keep Pethidine Hydrochloride at room temperature. Don't let it freeze, and keep it away from light.
Drug Interactions
Common questions about Pethidine-R 100 mg
What is Pethidine-R 100 mg Injection?
Pethidine-R 100 mg Injection is a medicine that contains Pethidine Hydrochloride. It is made by Renata PLC. It belongs to the Opioid analgesics group of medicines.
What is Pethidine-R used for?
Pethidine-R is used for: Pain.
What are the side effects of Pethidine-R?
Central Nervous System: Patients commonly notice lightheadedness, dizziness, sedation, and sweating, along with occasional bizarre sensations, disorientation, hallucinations, or psychosis. These effects tend to stand out more in patients who are up and about, or in those whose pain is not severe, and lying down after a slightly reduced dose often brings relief.
Can I take Pethidine-R during pregnancy or while breastfeeding?
Pregnancy Category C. Opioids can cause respiratory depression in a newborn, so pethidine should only be used during labour if the expected benefit to the mother is judged to outweigh the risk to the foetus. Talk to your doctor before taking any medicine during pregnancy or while breastfeeding.
What happens if I take too much Pethidine-R?
In an overdose of pethidine hydrochloride, the signs include CNS and respiratory depression, dilated pupils (mydriasis), a slow heart rate (bradycardia) and pulmonary oedema. Chronic tremor, CNS excitability and seizures can also occur. In an emergency call 999 or go to the nearest hospital emergency department.
How should I store Pethidine-R?
Keep Pethidine Hydrochloride at room temperature. Don't let it freeze, and keep it away from light.
Can I take other medicines with Pethidine-R?
Some medicines can interact with Pethidine Hydrochloride, for example: Cimetidine, Ritonavir, Pethidine, Phenytoin. Tell your doctor or pharmacist about every medicine you take.
Do I need a prescription for Pethidine-R?
Pethidine-R is a prescription (Rx) medicine. Take it as your doctor advises.