Nurses Compass
Drug Guide
Pentazocine Lactate
Classification
Therapeutic: Analgesic, Opioid
Pharmacological: Agonist-at-Opioid Receptor
FDA Approved Indications
- Management of moderate to severe pain
Mechanism of Action
Pentazocine is a mixed agonist-antagonist opioid that acts primarily as an agonist at kappa-opioid receptors and as an antagonist or partial agonist at mu-opioid receptors, producing analgesia with less respiratory depression compared to full mu-opioid agonists.
Dosage and Administration
Adult: 50 mg every 3 to 4 hours as needed; maximum dose varies with clinical response.
Pediatric: Use not generally recommended; refer to specific pediatric guidelines.
Geriatric: Start with lower doses due to increased sensitivity; monitor closely.
Renal Impairment: Adjust dose based on severity of impairment; cautious use.
Hepatic Impairment: Adjust dose as hepatic metabolism may be reduced.
Pharmacokinetics
Absorption: Well absorbed intramuscularly and subcutaneously.
Distribution: Widely distributed; crosses the blood-brain barrier.
Metabolism: Metabolized in the liver.
Excretion: Excreted mainly via the kidneys.
Half Life: Approximately 3 hours.
Contraindications
- Known hypersensitivity to pentazocine or other opioids.
- Respiratory depression, significant respiratory compromise.
Precautions
- Use with caution in patients with a history of substance abuse, head injury, increased intracranial pressure, hepatic impairment, or cardiovascular disease. May cause drug dependence.
Adverse Reactions - Common
- Dizziness (Common)
- Nausea (Common)
- Drowsiness (Common)
Adverse Reactions - Serious
- Respiratory depression (Serious, rare with proper dosing)
- Collaboration of dependence or abuse (Serious)
- Hypotension (Possible)
Drug-Drug Interactions
- CNS depressants (e.g., alcohol, benzodiazepines) increase sedative effects.
- MAO inhibitors may enhance respiratory depression and hypotension.
Drug-Food Interactions
N/ADrug-Herb Interactions
N/ANursing Implications
Assessment: Assess pain level before and after administration. Monitor respiratory rate closely.
Diagnoses:
- Pain, Risk for opioid addiction, Ineffective breathing pattern.
Implementation: Administer with caution, observe for signs of respiratory depression, and assess pain relief.
Evaluation: Evaluate effectiveness of pain control and any adverse effects.
Patient/Family Teaching
- Instruct patients to avoid alcohol and sedatives.
- Report signs of respiratory depression, excessive sedation, or allergic reactions.
- Use medication only as prescribed.
Special Considerations
Black Box Warnings:
- Respiratory depression risk, especially in opioid-naive patients and when combined with other CNS depressants.
Genetic Factors: Polymorphisms in opioid receptor genes may affect response.
Lab Test Interference: May interfere with certain laboratory tests related to liver function.
Overdose Management
Signs/Symptoms: Respiratory depression, somnolence, hypotension, possible coma.
Treatment: Administer opioid antagonist naloxone immediately, provide supportive respiratory and cardiovascular care.
Storage and Handling
Storage: Store at room temperature, away from light and moisture.
Stability: Stable under recommended storage conditions.