Meptazinol

Meptazinol is a opioid analgesic developed by Wellcome Research Laboratories in 1979. It is used in the treatment of moderate to severe pain, including pain in childbirth. It is an unusual opioid analgesic as it has a mixed agonist–antagonist effect, being a weak mu-opioid receptor antagonist and a weak kappa-opioid receptor agonist.

Pharmacology[edit | edit source]

Meptazinol has a rapid onset and short duration of action, with relatively little respiratory depression. It is used in obstetric care due to its short half-life and lower risk of respiratory depression in the newborn. It is less likely to cause nausea and vomiting than other opioids.

Chemistry[edit | edit source]

Meptazinol is a 3-phenylazepane derivative, which is a structurally different class than most other opioids. This may account for its different mechanism of action.

Side effects[edit | edit source]

Common side effects of meptazinol include nausea, vomiting, and dizziness. Less common side effects include hypotension, tachycardia, and hallucinations.

Contraindications[edit | edit source]

Meptazinol is contraindicated in patients with a known hypersensitivity to the drug, and in patients with respiratory depression, acute alcoholism, or where risk of paralytic ileus is high.