Nurses Compass
Drug Guide
Pentazocine Hydrochloride
Classification
Therapeutic: opioid analgesic
Pharmacological: kappa-opioid receptor agonist and weak mu-opioid receptor antagonist
FDA Approved Indications
- Moderate to severe pain management
Mechanism of Action
Pentazocine binds predominantly to kappa-opioid receptors producing analgesia, and weakly blocks mu-opioid receptors, which may diminish some opioid effects and reduce potential for dependence.
Dosage and Administration
Adult: 50 mg every 3 to 4 hours as needed, not to exceed 360 mg per day.
Pediatric: Not typically recommended for children.
Geriatric: Start at lower end of dosing range; monitor closely due to potential increased sensitivity and comorbidities.
Renal Impairment: Use with caution, adjustments based on clinical response and renal function.
Hepatic Impairment: Use with caution; hepatic impairment may alter drug metabolism.
Pharmacokinetics
Absorption: Rapidly absorbed after IM or subcutaneous injection.
Distribution: Widely distributed, crosses blood-brain barrier.
Metabolism: Metabolized in the liver via conjugation.
Excretion: Excreted mainly via urine.
Half Life: Approximately 2 to 4 hours.
Contraindications
- History of hypersensitivity to pentazocine or other opioids.
- Significant respiratory depression.
- Head injury or increased intracranial pressure.
Precautions
- Use with caution in patients with substance abuse history, during labor, or in patients with liver impairment. Risk of dependence and abuse exists.
Adverse Reactions - Common
- Dizziness (Common)
- Nausea (Common)
- Drowsiness (Common)
Adverse Reactions - Serious
- Respiratory depression (Uncommon)
- Hypotension (Uncommon)
- Psychotomimetic effects (e.g., hallucinations) (Rare)
Drug-Drug Interactions
- Alcohol, sedatives, tranquilizers may increase sedation and respiratory depression.
- MAO inhibitors may enhance adverse effects.
Drug-Food Interactions
N/ADrug-Herb Interactions
N/ANursing Implications
Assessment: Assess pain relief, respiratory status, and level of consciousness before and during therapy.
Diagnoses:
- Risk for respiratory depression
- Risk for addiction
- Impaired comfort
Implementation: Administer cautiously, verify dose, monitor vital signs and pain levels regularly.
Evaluation: Evaluate effectiveness of pain relief and monitor for adverse effects.
Patient/Family Teaching
- Take medication exactly as prescribed.
- Do not exceed prescribed dose.
- Rise slowly to avoid dizziness.
- Report signs of respiratory depression or allergic reactions.
- Avoid alcohol and sedatives.
Special Considerations
Black Box Warnings:
- Risk of addiction, abuse, and misuse leading to overdose and death.
- Respiratory depression risk.
Genetic Factors: Genetic variations may influence metabolism and response.
Lab Test Interference: May interfere with certain lab tests, such as those measuring hepatic or renal function.
Overdose Management
Signs/Symptoms: Respiratory depression, extreme drowsiness, hypotension, coma.
Treatment: Support airway, provide oxygen, administer naloxone if respiratory depression occurs, provide ventilatory support if needed.
Storage and Handling
Storage: Store at controlled room temperature, 20-25°C (68-77°F).
Stability: Stable under standard conditions; avoid excessive moisture or heat.