| | System Organ Class | Very Common ( 1/10) | Uncommon ( 1/1,000 to 1/100) | | Nervous system disorders
| dizziness, headache, vertigo, somnolence, drowsiness
| | | Vascular disorders
| | hypotension
| | Respiratory, thoracic and mediastinal disorders
| | Respiratory depression
| | Gastrointestinal disorders
| abdominal pain, constipation, diarrhoea, dyspepsia, nausea, vomiting | | | Skin and subcutaneous tissue disorders
| Increased sweating, rash
| | For very rare reports of psychiatric disorders (hallucination, confusion, depression), causal relationship with the use of meptazinol has not been established and therefore omitted from the above table. Reactions not already stated which are attributable to opioid analgesics include difficulty with micturition, ureteric or biliary spasm, dry mouth, facial flushing, bradycardia, tachycardia, palpitations, hypothermia, dysphoria, mood changes, miosis, decreased libido or potency, urticaria and pruritus. | |