Petidin Viatris (Pethidine): Uses, Dosage & Side Effects
Opioid analgesic for the management of severe acute pain
Quick Facts about Petidin Viatris
Key Takeaways
- Hospital use only: Petidin Viatris is given by injection by healthcare professionals and is not a self-administered medication
- Short-term use recommended: Due to the toxic metabolite norpethidine, treatment should ideally be limited to less than 48 hours
- Never combine with MAO inhibitors: This combination can cause a life-threatening reaction including serotonin syndrome, seizures, and death
- Risk of dependence: Pethidine is an opioid with significant potential for physical and psychological dependence
- Caution in pregnancy: Use during labour may cause neonatal respiratory depression; prolonged use can lead to neonatal withdrawal
What Is Petidin Viatris and What Is It Used For?
Petidin Viatris contains pethidine hydrochloride, a strong opioid (narcotic) analgesic that belongs to the phenylpiperidine class. It is used for the management of severe acute pain conditions in hospital or clinical settings, where it is administered by a healthcare professional via intramuscular, intravenous, or subcutaneous injection.
Pethidine, known as meperidine in the United States, was first synthesised in 1939 and became one of the most widely used opioid analgesics during the mid-20th century. It acts primarily on mu-opioid receptors in the central nervous system to block the transmission of pain signals and produce analgesia. Unlike morphine, pethidine also possesses weak local anaesthetic properties and some atropine-like (anticholinergic) effects, which historically made it a favoured choice for certain clinical scenarios.
In contemporary practice, the use of pethidine has declined significantly in many countries. This shift reflects growing awareness of its unfavourable pharmacokinetic profile compared to other opioids. The primary concern is norpethidine, a neurotoxic metabolite produced during hepatic metabolism that has a half-life of 15 to 20 hours — substantially longer than pethidine itself (3 to 5 hours). Accumulation of norpethidine, particularly with repeated dosing, can lead to central nervous system excitation, including tremors, myoclonus, and generalised seizures.
Despite these concerns, pethidine continues to have specific clinical roles. It remains used in some centres for labour analgesia, post-operative shivering (due to its unique anti-shivering properties not shared by other opioids), and as a short-term analgesic for acute severe pain. Organisations such as the European Medicines Agency (EMA), the British National Formulary (BNF), and the Australian and New Zealand College of Anaesthetists (ANZCA) have all issued guidance recommending restricted use and highlighting the availability of safer alternatives for most indications.
The World Health Organization (WHO) recognises pethidine on its Model List of Essential Medicines for limited indications. However, many national guidelines, including those from NICE in the United Kingdom, recommend morphine or fentanyl as first-line opioid analgesics for acute pain, reserving pethidine only when other options are contraindicated or for specific indications such as post-operative shivering.
What Should You Know Before Taking Petidin Viatris?
Pethidine is contraindicated in patients with severe respiratory depression, excessive airway secretions, alcohol or sedative intoxication, and those taking MAO inhibitors. Multiple conditions require special caution, and your doctor will carefully assess whether pethidine is appropriate for you.
Contraindications
Do not use Petidin Viatris if you:
- Are allergic to pethidine or any of the other ingredients (water for injections)
- Have conditions with excessive mucus in the airways (as pethidine suppresses the cough reflex)
- Have significantly reduced respiratory function or severe respiratory depression
- Are in a state of agitation caused by alcohol or sedative intoxication
- Are currently taking or have taken MAO inhibitors (monoamine oxidase inhibitors) within the preceding 14 days, including medications such as moclobemide, selegiline, phenelzine, or tranylcypromine
The combination of pethidine with MAO inhibitors (monoamine oxidase inhibitors) can trigger a severe, potentially fatal reaction. This may manifest as serotonin syndrome, characterised by extreme agitation, hyperthermia, muscle rigidity, autonomic instability, seizures, cardiovascular collapse, and death. This contraindication is absolute — pethidine must never be given to a patient taking or recently having taken any MAO inhibitor. A washout period of at least 14 days is required after discontinuation of an MAO inhibitor before pethidine can be considered safe to administer.
Warnings and Precautions
Speak with your doctor, pharmacist, or nurse before using Petidin Viatris if you have any of the following conditions:
- Asthma or chronic obstructive pulmonary disease (COPD): Pethidine can depress respiration and suppress the cough reflex, potentially worsening these conditions
- Head injury or raised intracranial pressure: Opioids can further increase intracranial pressure and impair neurological assessment
- Low blood pressure (hypotension) with reduced blood volume: Pethidine can cause further blood pressure drops
- Impaired liver or kidney function: The metabolism of pethidine and clearance of norpethidine are affected, increasing toxicity risk
- Epilepsy: Norpethidine lowers the seizure threshold and can provoke convulsions
- Cardiac arrhythmias: Pethidine may affect heart rhythm
- Elderly patients: Increased sensitivity to opioid effects and greater risk of norpethidine accumulation due to age-related decline in renal function
Like all opioids, pethidine carries a risk of physical and psychological dependence. This risk increases with the duration of use and the dose administered. Tolerance (reduced effect with repeated use) can develop, requiring dose escalation to achieve the same analgesic effect. For these reasons, pethidine should be used for the shortest possible duration and at the lowest effective dose.
Pregnancy and Breastfeeding
If you are pregnant, breastfeeding, think you may be pregnant, or are planning to have a baby, ask your doctor for advice before receiving this medicine.
Pregnancy: The use of pethidine during labour is established clinical practice in many hospitals worldwide, but it can cause respiratory depression in the newborn. Neonatal monitoring and access to the opioid antagonist naloxone must be available when pethidine is administered during delivery. Prolonged use of pethidine during pregnancy can result in neonatal abstinence syndrome (withdrawal symptoms in the newborn), which may include irritability, excessive crying, tremors, feeding difficulties, and in severe cases, seizures.
Breastfeeding: Pethidine passes into breast milk. Repeated doses can accumulate in the nursing infant, especially as neonates metabolise pethidine much more slowly than adults. The BNF recommends that breastfeeding mothers discuss the risks with their healthcare provider and that pethidine should be used with caution during breastfeeding.
Driving and Operating Machinery
Petidin Viatris can significantly impair your ability to drive or operate machinery because it may cause drowsiness, dizziness, and reduced reaction time. These effects can persist after the primary analgesic effect has worn off. You must not drive, operate heavy machinery, or perform any tasks requiring mental alertness until you are confident that pethidine is no longer affecting your judgement and coordination. You are personally responsible for assessing whether you are fit to perform these activities.
Alcohol
Alcohol must not be consumed during treatment with Petidin Viatris. The combination of alcohol and pethidine has a synergistic depressant effect on the central nervous system, which can lead to profound sedation, dangerously reduced respiratory function (respiratory depression), cardiovascular collapse, and potentially death.
How Does Petidin Viatris Interact with Other Drugs?
Pethidine has numerous clinically significant drug interactions. The most dangerous is with MAO inhibitors, which is an absolute contraindication. Co-administration with other CNS depressants increases the risk of fatal respiratory depression. Serotonergic drugs carry a risk of serotonin syndrome.
Always inform your doctor, pharmacist, or nurse about all medications you are taking, have recently taken, or might take. Pethidine interacts with a wide range of drugs through multiple pharmacological mechanisms, making a thorough medication history essential before administration.
Major Interactions (Avoid Combination)
| Drug / Drug Class | Risk | Mechanism |
|---|---|---|
| MAO inhibitors (moclobemide, selegiline, phenelzine) | Life-threatening serotonin syndrome, seizures, death | Inhibition of serotonin metabolism leading to serotonin excess |
| Benzodiazepines (diazepam, midazolam, lorazepam) | Profound sedation, respiratory depression, coma, death | Additive CNS depression |
| Other opioid analgesics (morphine, fentanyl, tramadol) | Severe respiratory depression, coma | Additive opioid receptor activation |
| General anaesthetics | Respiratory depression, prolonged sedation | Additive CNS depression |
| Barbiturates (phenobarbital) | Respiratory depression, excessive sedation | Additive CNS depression and enzyme induction |
Moderate Interactions (Use with Caution)
| Drug / Drug Class | Risk | Clinical Advice |
|---|---|---|
| SSRIs (fluoxetine, sertraline, citalopram, paroxetine) | Serotonin syndrome cannot be excluded | Monitor for agitation, confusion, tremor, hyperthermia |
| SNRIs (venlafaxine, duloxetine) | Serotonin syndrome risk | Close clinical monitoring required |
| St John's wort (Hypericum perforatum) | Serotonin syndrome risk | Avoid combination; enquire about herbal supplements |
| Carbamazepine | Increased norpethidine formation | Enzyme induction accelerates toxic metabolite production |
| Phenytoin | Reduced pethidine efficacy, increased norpethidine | Hepatic enzyme induction alters metabolism |
| Ritonavir (HIV protease inhibitor) | Altered pethidine metabolism | Monitor for both efficacy changes and toxicity |
| Phenothiazines (chlorpromazine) | Enhanced sedation, hypotension | Dose reduction may be needed |
| Muscle relaxants | Enhanced CNS depression | Monitor respiratory function closely |
| Sedating antihistamines | Increased drowsiness and sedation | Limit concurrent use; adjust doses |
Because of the complexity of pethidine's interaction profile, clinicians should always conduct a thorough review of a patient's current medications — including over-the-counter products and herbal supplements — before initiating treatment. The concurrent use of pethidine with any CNS depressant should only be considered when no alternative treatment options exist, and when used, both the dose and duration should be minimised.
If you are receiving pethidine, it is advisable to inform close friends or family members about the signs and symptoms of serious adverse effects, particularly drowsiness, slow or shallow breathing, confusion, and unresponsiveness. Early recognition of these warning signs can be life-saving.
What Is the Correct Dosage of Petidin Viatris?
Pethidine is administered by a doctor or nurse who will determine the appropriate dose based on the severity of pain, the patient's weight, age, general health, and response to treatment. The medicine is given by injection (intramuscular, subcutaneous, or intravenous).
Petidin Viatris is not a medicine that patients self-administer. It is given exclusively by qualified healthcare professionals in a clinical setting. Your doctor will carefully individualise the dose to achieve effective pain relief while minimising the risk of adverse effects. The following dosage information is provided for educational reference only and reflects general guidelines from international sources such as the BNF and EMA-approved product information.
Adults
Standard Adult Dosage
Intramuscular or subcutaneous injection: 25–100 mg every 3–4 hours as needed. The typical starting dose is 50–100 mg.
Intravenous injection: 25–50 mg by slow IV injection, repeated as needed. Must be given slowly to reduce the risk of adverse cardiovascular effects.
Maximum recommended duration: Treatment should ideally not exceed 48 hours to avoid norpethidine accumulation. The maximum daily dose should not exceed 600 mg in a 24-hour period.
Children
Paediatric Dosage
Dosing in children is determined by body weight and must be carefully calculated by the prescribing physician. General paediatric dosing is approximately 0.5–2 mg/kg body weight per dose, administered intramuscularly. Use in neonates and infants requires extreme caution due to their immature drug metabolism. Many paediatric guidelines now recommend alternative opioids (such as morphine) as first-line agents in preference to pethidine in children.
Elderly Patients
Elderly Dosage Considerations
Elderly patients are more susceptible to the effects of opioids and to norpethidine toxicity due to age-related declines in renal clearance. Lower starting doses and longer dosing intervals are recommended. Many clinical guidelines explicitly discourage the use of pethidine in elderly patients and recommend alternative opioids with more predictable pharmacokinetics.
Overdose
The likelihood of receiving an overdose is low because pethidine is administered by healthcare professionals. However, symptoms of overdose may include:
- Severe dizziness and confusion
- Extreme drowsiness progressing to unconsciousness
- Markedly slow, shallow, or absent breathing
- Pinpoint pupils (miosis)
- Cold, clammy skin
- Muscle twitching, tremors, and seizures (due to norpethidine)
- Nausea and agitation
- Cardiovascular collapse
Treatment of pethidine overdose requires immediate medical intervention. Naloxone, an opioid antagonist, is the specific antidote for reversing opioid-induced respiratory depression. However, naloxone does not reverse the excitatory neurotoxic effects caused by norpethidine — seizures from norpethidine accumulation require separate anticonvulsant management. In case of suspected overdose, contact emergency services immediately.
What Are the Side Effects of Petidin Viatris?
Like all opioid medications, pethidine can cause side effects, although not everybody gets them. Many side effects are dose-dependent. The most common include nausea, vomiting, and dry mouth. Serious effects such as respiratory depression, seizures, and dependence require immediate medical attention.
The following side effect profile is based on the approved product information and international pharmacovigilance data. As with all opioids, there is a risk of dependence with Petidin Viatris. Your healthcare team will monitor you closely during treatment.
Very Common
May affect more than 1 in 10 people
- Nausea
- Vomiting
- Dry mouth
Uncommon
May affect up to 1 in 100 people
- Euphoria (feeling of intense well-being)
- Dizziness
- Respiratory depression (reduced breathing)
- Drowsiness
- Fainting episodes (syncope)
- Low blood pressure (hypotension)
- Palpitations (awareness of heartbeat)
- Constipation
- Biliary spasm (pain in the bile duct area)
- Urticaria (hives)
- Skin flushing
- Difficulty urinating (urinary retention)
Frequency Not Known
Cannot be estimated from available data
- Seizures (convulsions) — particularly with repeated dosing or renal impairment
- Muscle twitching (myoclonus)
- Tremors
The excitatory neurotoxic effects listed in the “frequency not known” category — seizures, myoclonus, and tremors — are specifically related to the accumulation of norpethidine, the active metabolite of pethidine. These effects are more likely to occur with:
- Repeated or prolonged dosing (exceeding 48 hours)
- High cumulative doses
- Renal impairment (reduced clearance of norpethidine)
- Co-administration with enzyme-inducing drugs (e.g. carbamazepine, phenytoin) that accelerate norpethidine formation
- Patients with pre-existing epilepsy or lowered seizure threshold
Contact a healthcare professional immediately if you experience any of the following: slow or difficult breathing, severe drowsiness or difficulty staying awake, confusion or disorientation, seizures or muscle twitching, severe allergic reactions (swelling of the face, lips, tongue or throat, difficulty breathing), or extreme dizziness with fainting.
Reporting suspected side effects after a medicine has been authorised is important. It allows continuous monitoring of the medicine's benefit-risk balance. Healthcare professionals and patients are encouraged to report any suspected adverse reactions to their national pharmacovigilance authority — for example, the MHRA Yellow Card Scheme in the United Kingdom, MedWatch in the United States, or the EMA's EudraVigilance system in the European Union.
How Should You Store Petidin Viatris?
Petidin Viatris is stored and handled by healthcare professionals in clinical settings. It is a controlled substance requiring secure storage in accordance with national controlled drugs legislation.
Keep this medicine out of the sight and reach of children at all times. Do not use this medicine after the expiry date which is stated on the label after “EXP.” The expiry date refers to the last day of that month. As a controlled substance, pethidine must be stored in a locked cabinet or safe that complies with local controlled drugs regulations.
Do not throw away any medicines via wastewater or household waste. Ask your pharmacist how to throw away medicines you no longer use. These measures will help to protect the environment. Unused controlled substances must be returned to the pharmacy or disposed of in accordance with local controlled drugs procedures — they must never be discarded through normal waste channels.
What Does Petidin Viatris Contain?
Petidin Viatris contains pethidine hydrochloride as the active substance. The only excipient is water for injections.
The formulation is notably simple:
- Active substance: Pethidine in the form of pethidine hydrochloride, at a concentration of 50 mg/ml
- Other ingredient: Water for injections
The medicine is supplied as a clear, colourless solution in glass ampoules. Each pack contains 10 ampoules of 1 ml. The solution is intended for single use only; any unused solution remaining after administration should be discarded.
Petidin Viatris contains no preservatives, no animal-derived ingredients, and is free from gluten, lactose, and common allergens (other than pethidine itself). The absence of excipients beyond water for injections makes adverse reactions attributable to inactive ingredients extremely unlikely, although allergy to pethidine itself remains a contraindication.
Frequently Asked Questions
Petidin Viatris contains pethidine (also known as meperidine), a strong opioid analgesic used for the management of severe acute pain. It is administered by injection (intramuscular, subcutaneous, or intravenous) in hospital settings. Common clinical uses include post-operative pain, labour analgesia, and post-operative shivering. It is not intended for long-term pain management or self-administration.
The most common side effects (affecting more than 1 in 10 people) are nausea, vomiting, and dry mouth. Less common side effects include euphoria, dizziness, drowsiness, respiratory depression, fainting, low blood pressure, palpitations, constipation, biliary spasm, urticaria, flushing, and difficulty urinating. With repeated dosing, norpethidine accumulation can cause tremors, muscle twitching, and seizures.
Pethidine is sometimes used for labour analgesia under medical supervision, but it can cause respiratory depression in the newborn, requiring naloxone to be immediately available. Prolonged use during pregnancy may lead to neonatal abstinence syndrome (withdrawal symptoms). Pethidine passes into breast milk and should be used with caution during breastfeeding. Always discuss the risks and benefits with your doctor.
Pethidine is metabolised in the liver to norpethidine, a toxic metabolite with a half-life of 15–20 hours. Norpethidine accumulates with repeated dosing and can cause excitatory neurotoxic effects including tremors, myoclonus, and generalised seizures. Importantly, these effects are not reversed by naloxone. Many international guidelines now recommend limiting pethidine to short courses (ideally less than 48 hours) and preferring morphine or fentanyl for longer-term pain management.
Pethidine must never be used with MAO inhibitors (such as moclobemide, selegiline, phenelzine, or tranylcypromine) as this can cause fatal serotonin syndrome. Caution is also required with benzodiazepines, other opioids, general anaesthetics, barbiturates, SSRI antidepressants, SNRI antidepressants, phenothiazines, muscle relaxants, carbamazepine, phenytoin, ritonavir, and St John's wort. Always tell your doctor about all medications you are taking.
Yes, pethidine is an opioid and carries a significant risk of both physical and psychological dependence. It is classified as a controlled substance in most countries. Tolerance can develop with repeated use, requiring higher doses for the same effect. For these reasons, pethidine should be used for the shortest possible duration and at the lowest effective dose, under direct medical supervision only.
References
- European Medicines Agency (EMA). Pethidine – Summary of Product Characteristics. Available at: www.ema.europa.eu
- British National Formulary (BNF). Pethidine hydrochloride. Available at: bnf.nice.org.uk
- World Health Organization (WHO). WHO Model List of Essential Medicines, 23rd List (2023). Available at: www.who.int
- Latta KS, Ginsberg B, Barkin RL. Meperidine: a critical review. American Journal of Therapeutics. 2002;9(1):53–68.
- Szeto HH, Inturrisi CE, Houde R, et al. Accumulation of normeperidine, an active metabolite of meperidine, in patients with renal failure or cancer. Annals of Internal Medicine. 1977;86(6):738–741.
- National Institute for Health and Care Excellence (NICE). Acute pain management: guidance on the use of opioid analgesics. Available at: www.nice.org.uk
- Australian and New Zealand College of Anaesthetists (ANZCA). Acute Pain Management: Scientific Evidence, 5th Edition (2020). Statement on the use of pethidine.
- Cochrane Drugs and Alcohol Group. Parenteral opioids for labour pain – a systematic review. Cochrane Database of Systematic Reviews. 2023.
- Food and Drug Administration (FDA). Meperidine hydrochloride prescribing information. Available at: www.fda.gov
- International Association for the Study of Pain (IASP). Guidelines on the pharmacological management of acute pain. 2022.
About the Editorial Team
This article has been written and medically reviewed by the iMedic Medical Editorial Team, comprising specialist physicians with expertise in clinical pharmacology, pain medicine, and anaesthesiology. All medical information follows international guidelines from the WHO, EMA, BNF, NICE, and the IASP, and adheres to the GRADE evidence framework.
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