ABSTRACT
Pentazocine injectable formulations are available in both single-unit dose ampules and cartridge-needle injection delivery systems. Pentazocine primarily elicits its analgesic, CNS depressant, and respiratory depressant actions by binding to the endorphin receptors in the CNS. Pentazocine’s analgesic action occurs within 3 minutes after intravenous injection and within 30 minutes after intramuscular or subcutaneous injection. Pentazocine is addicting and habituating. Long-term pentazocine pharmacotherapy, or regular personal use, may result in addiction and habituation. Pentazocine has mixed opiate agonist/antagonist actions. Acute onset of confusion, disorientation, and hallucinations have been reported among some patients who were receiving recommended dosages of pentazocine. Oral pentazocine pharmacotherapy commonly has been associated with nausea, sedation, somnolence, vertigo, and vomiting. Sedation may be more marked among elderly, frail, or debilitated patients. Injectable pentazocine pharmacotherapy has been commonly associated with dizziness, euphoria, lightheadedness, nausea, stinging upon injection, and vomiting.
