Concise Prescribing Info
Moderate to severe pain.
Dosage/Direction for Use
Adult : PO 50-100 mg 3-4 hrly. Max: 600 mg/day. IV/IM/SC 30-60 mg 3-4 hrly. Rectal As 50 mg supp: 1 supp ≤4 times/day.
Dosage Details
Moderate to severe pain
Adult: 50-100 mg every 3-4 hrs; max 600 mg daily.
Child: 6-12 yr: As hydrochloride: 25 mg every 3-4 hr.

Moderate to severe pain
Adult: 30-60 mg SC, IM or IV Inj given every 3-4 hr.
Child: >1 yr: up to 1 mg/kg SC, IM; up to 500 mcg/kg IV every 3-4 hr.

Moderate to severe pain
Adult: 50 mg supp up to 4 times daily.
Child: Not recommended.
Renal Impairment
<1050% normal dose.
10-5075% normal dose.
<1050% normal dose.
10-5075% normal dose.
< 1050% normal dose
10-5075% normal dose
Hepatic Impairment
Reduce dose or avoid in liver disease.
Should be taken with food.
At Y site: Nafcillin; when admixed: aminophylline, amobarbital, pentobarbital, phenobarbital, sodium bicarbonate; in syringe: glycopyrrolate, heparin, phenobarbital.
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).
Special 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.
Adverse Reactions
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.
IM/IV/Parenteral/PO/SC: C
Symptoms: respiratory depression, cardiovascular, CNS effects. Treatment: empty stomach by lavage or emesis (lavage in comatose patients or those without gag reflex must have an endotracheal tube). For respiratory depression: parenteral naloxone and supportive treatment such as oxygen, IV fluids and vasopressors.
Drug Interactions
Depressant affects potentiated by alcohol, CNS depressants; concurrent use with fluoxetine may lead to diaphoresis, ataxia flushing and tremor associated with serotonin syndrome.
Description: 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.
Onset: Oral, IM, SC: 15-30 minutes; IV 2-3 minutes.
Duration: Oral: 4-5 hr; parenteral: 2-3 hr.
Absorption: Absorbed from the GI tract (oral), through the muscles (IM); peak plasma concentrations after 1-3 hr (oral), 15 min-1 hr (IM). Oral bioavailability: approx 20% (60-70% in cirrhosis).
Distribution: Crosses the placenta. Protein-binding: 60%
Metabolism: Hepatic; via oxidative and glucuronide conjugation pathways; extensive 1st pass.
Excretion: Elimination half life: 2-3 hr; prolonged in hepatic impairment; excretion via urine (small amounts as unchanged drug).
MIMS Class
Disclaimer: This information is independently developed by MIMS based on Pentazocine from various references and is provided for your reference only. Therapeutic uses, prescribing information and product availability may vary between countries. Please refer to MIMS Product Monographs for specific and locally approved prescribing information. Although great effort has been made to ensure content accuracy, MIMS shall not be held responsible or liable for any claims or damages arising from the use or misuse of the information contained herein, its contents or omissions, or otherwise. Copyright © 2020 MIMS. All rights reserved. Powered by
  • Pentazocine Fresenius
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