Pentazocine Hydrochloride

Indications

Pentazocine Hydrochloride is used for: Moderate to severe pain

Adult Dose

Oral Moderate to severe pain Adult: 50-100 mg every 3-4 hrs; max 600 mg daily. Hepatic impairment: Reduce dose or avoid in liver disease.

Child Dose

Oral Moderate to severe pain Child: 6-12 yr: 25 mg every 3-4 hr.

Renal Dose

Renal impairment: CrCl (ml/min) Dosage Recommendation 10-50 75% normal dose. <10 50% normal dose.

Administration

Should be taken with food. Take after meals.

Contra Indications

Head injury; narcotic dependence; respiratory depression; raised intracranial pressure; MI; heart failure; arterial or pulmonary hypertension; porphyria; pregnancy (prolonged use or high doses at term).

Precautions

May precipitate withdrawal in narcotic addicts. Impaired respiratory, renal and hepatic function; morbidly obese patients; thyroid dysfunction; prostatic hyperplasia or urinary stricture; biliary tract impairment; adrenal insufficiency (including Addison's disease); abdominal conditions. Elderly or debilitated patients; seizure-prone patients; children and infants (safety and efficacy not established in <1 yr); lactation. May impair ability to drive or operate machinery. Administer IM rather than SC (when frequent inj are needed) and inj sites should be varied. Lactation: unknown if excreted in breast milk, use caution

Pregnancy-Lactation

Pregnancy Category: C; D if used for prolonged periods or near term

Interactions

Depressant affects potentiated by alcohol, CNS depressants; concurrent use with fluoxetine may lead to diaphoresis, ataxia flushing and tremor associated with serotonin syndrome.

Adverse Effects

Side effects of Pentazocine Hydrochloride : Physical dependence; sedation, dizziness, euphoria, lightheadedness, alterations of mood; respiratory depression; visual hallucinations, disorientation, confusion; hypertension, tachycardia, circulatory depression; shock; hypotension; nausea, vomiting, constipation; seizures, diaphoresis; rash; blood dyscrasias; local tissue damages (SC), muscle fibrosis (IM). Potentially Fatal: Respiratory depression, hypotension, circulatory failure, deepening coma, convulsions.

Mechanism of Action

Pentazocine is a benzomorphan derivative with mixed opioid agonist and antagonist actions. It alters perception of and response to pain and produces generalised CNS depression by binding to opiate receptors in the CNS and acting as a partial agonist/antagonist.