Clinical Pharmacology

Hydrocodone is a semi synthetic narcotic analgesic and antitussive with multiple actions qualitatively similar to those of codeine. Smooth muscle and central nervous system can be involved. The precise mechanism of action of hydrocodone and other opiates is not known, although it is believed to relate to the existence of opiate receptors in the central nervous system. In addition to analgesia, narcotics may produce drowsiness, changes in mood and mental clouding.

The analgesic action of the acetaminophen contains peripheral influences. Activity such as antipyretic is mediated through the hypothalamic heat regulating centers. prostaglandin synthetase inhibited by acetaminophen..

Pharmacokinetics:

Individual component's behavior is given below:

Hydrocodone: The 10mg oral dose of the hydrocodone manage to 5 adult male subjects, the mean peak concentration was 23.6 +/- 5.2ng/mL. Maximum serum levels were achieved at 1.3 +/- 0.3 hours and the half-life was determined to be 3.8 +/- 0.3 hours. Hydrocodone exhibits a complex pattern of metabolism including O-demethylation, N-demethylation and 6-keto reduction to the corresponding 6-a - hydroxy- metabolites. See overdosage for toxicity information.

Acetaminophen: Acetaminophen is rapidly absorbed from the gastrointestinal tract and is distributed throughout most body tissues. The plasma half-life is 1.25 to 3 hours, but may be increased by liver damage and following overdosage. Elimination of acetaminophen is principally by liver metabolism (conjugation) and subsequent renal excretion of metabolites. Approximately 85% of an oral dose appears in the urine within 24 hours of administration, most as the glucuronide conjugate, with small amounts of other conjugates and unchanged drug. See OVERDOSAGE for toxicity information.