📋 Indications & Clinical Dosage
*Moderate to severe pain:*
BY IM INJ, OR BY IV INJ, OR BY IV INF: Adult & Children above 12 yrs: 50-100 mg every 4-6 hours, intravenous injection to be given over 2-3 minutes.
*Moderate to severe acute pain:*
ORAL: Adult & Children above 12 yrs: Initially 100 mg, then 50-100 mg every 4-6 hours; Usual max. 400 mg/24 hours.
*Moderate to severe chronic pain:*
ORAL: Adult & Children above 12 yrs: Initially 50 mg, then, adjusted according to response; Usual max. 400 mg/24 hours.
*Postoperative pain:*
BY IV INJ: Adult & Children above 12 yrs: Initially 100 mg, then 50 mg every
10-20 minutes if required up to total max. 250mg (including initial dose) in first hour, then 50-100 mg every 4-6 hours, intravenous injection to be given over 2-3 minutes; max. 600 mg per day.
💊 Mode of Administration
Continuous or intermittent in dextrose 5% or sodium chloride 0.9% or LR.
⛔ Contraindications
Acute respiratory depression, comatose patients, head injury and raised intracranial pressure (opioid analgesics interfere with pupillary responses vital for neurological assessment), risk of paralytic ileus, acute intoxication with alcohol, hypnotics, analgesics or other CNS-acting drugs.
⚠️ Precautions & Warnings
Renal or hepatic impairment, adrenocortical insufficiency and hypothyroidism (reduced dose), asthma (avoid during an acute attack), convulsive disorders, diseases of the biliary tract, hypotension, elderly and debilitated patients (reduced dose), impaired respiratory function (avoid in chronic obstructive pulmonary disease), inflammatory bowel disorders, myasthenia gravis, obstructive bowel disorders, prostatic hypertrophy, shock, urethral stenosis, history of opioid abuse.
🔄 Drug Interactions
Tranquillizers, hypnotics and other substances which act on the central nervous system, MAO inhibitors.
⚠️ Adverse Reactions / Side Effects
Biliary spasm, bradycardia, confusion, constipation, dependence, difficulty with micturition, dizziness, drowsiness, dry mouth, dysphoria, euphoria, flushing, hallucinations, headache, hypotension and muscle rigidity (larger doses), miosis, nausea, oedema, palpitation, postural hypotension, pruritus, rash, respiratory depression (larger doses), sexual dysfunction, sleep disturbances, sweating, tachycardia, ureteric spasm, urinary retention, urticaria, vertigo, visual disturbances, vomiting, Adrenal insufficiency and hyperalgesia (long-term use), hypogonadism (long-term use)
🤰 Pregnancy & Lactation Safety
Pregnancy Risk:
Positive evidence of risk: Respiratory depression and withdrawal symptoms in the neonate; gastric stasis and inhalation pneumonia in the mother if opioid analgesics are used during labour and
Lactation / Breastfeeding:
: Contraindicated or not recommended.
🧪 Compatibility & Storage Stability
Stability & Storage: Store at controlled room temperature 25C.
📚 Official Regulatory & Clinical References
- Drug Regulatory Authority of Pakistan (DRAP): Drug Registration, S.R.O. Price Gazettes & National Essential Medicines List (NEML).
- World Health Organization (WHO): Collaborating Centre for Drug Statistics Methodology (ATC/DDD Index).
- Formulary Standards: British National Formulary (BNF) & Pakistan National Formulary (PNF) guidelines.