pentazocine hydrochloride /pentā″zəsēn/ , an agonist/antagonist opioid analgesic that stimulates kappa opioid receptors and blocks the mu opioid receptors. Also called pentazocine lactate. ▪ INDICATIONS: It is prescribed for the relief of moderate to severe pain. ▪ CONTRAINDICATIONS: Known hypersensitivity to this drug prohibits its use. It is administered with caution to patients with head injury, seizures, acute myocardial infarction, or kidney or liver dysfunction and to those undergoing biliary surgery. Pentazocine can cause withdrawal symptoms in patients with a history of opioid drug abuse and dependency. ▪ ADVERSE EFFECTS: Nausea and dizziness commonly occur. Other minor problems include constipation, malaise, headache, restlessness, urinary tract spasms, blurred vision, miosis, and drowsiness. High doses may cause respiratory or circulatory depression and coma.
