indication

Indicated in the treatment of moderate to severe pain.

pharmacology

Dezocine is a parenteral narcotic analgesic possessing both agonist and antagonist activity. It is similar to morphine with respect to analgesic potency and onset and duration of action. The narcotic antagonist activity is greater than that of pentazocine.

mechanism of action

Dezocine is a opioid analgesic drug of mixed agonist-antagonist type. It binds with stereospecific receptors at many sites within the central nervous system (CNS) to alter processes affecting both the perception of pain and the emotional response to pain. At least 2 of these types of receptors (mu and kappa) mediate analgesia. Mu receptors are widely distributed throughout the CNS, especially in the limbic system (frontal cortex, temporal cortex, amygdala, and hippocampus), thalamus, striatum, hypothalamus, and midbrain as well as laminae I, II, IV, and V of the dorsal horn in the spinal cord. Kappa receptors are localized primarily in the spinal cord and in the cerebral cortex.

toxicity

Symptoms of overdose include cold and clammy skin, confusion, nervousness, or severe restlessness, convulsions (seizures), severe dizziness, severe drowsiness, low blood pressure, pinpoint pupils of eyes, slow heartbeat, slow or troubled breathing and severe weakness.

biotransformation

Hepatic, via conjugation (glucuronidation).

absorption

Rapid and complete following intramuscular administration.

half life

Elimination half-life following intramuscular administration averages 2.2 hours. Elimination half-life following a 5mg intravenous dose averages 1.7 to 2.6 hours (range 0.6 to 4.4 hours) while a 10mg dose averages 2.4 to 2.6 hours (range 1.2 to 7.4 hours). In patients with hepatic cirrhosis, the half-life is increased by 30 to 50%.