Home Drug Guide Pentazocine Lactate

Drug Guide

Generic Name

Pentazocine Lactate

Brand Names Talwin

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/A

Drug-Herb Interactions

N/A

Nursing 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.