Home Drug Guide Propoxyphene Napsylate

Drug Guide

Generic Name

Propoxyphene Napsylate

Brand Names Darvon-n W/ ASA

Classification

Therapeutic: Analgesic, Pain Reliever

Pharmacological: Narcotic (opioid) analgesic

FDA Approved Indications

Management of mild to moderate pain

Mechanism of Action

Propoxyphene is a centrally acting narcotic analgesic that modulates pain perception in the brain through its affinity for the μ-opioid receptor. It also has a weak local anesthetic effect.

Dosage and Administration

Adult: Typically 65-130 mg every 4 hours as needed; maximum daily dose varies by formulation.

Pediatric: Not recommended due to safety concerns.

Geriatric: Use with caution; lower initial doses recommended due to increased sensitivity and risk of adverse effects.

Renal Impairment: Dose adjustment recommended; avoid in severe impairment.

Hepatic Impairment: Use with caution; monitor for increased effects.

Pharmacokinetics

Absorption: Rapidly absorbed from the gastrointestinal tract.

Distribution: Extensively bound to plasma proteins.

Metabolism: Extensively metabolized in the liver, primarily by conjugation.

Excretion: Excreted mainly in urine.

Half Life: Approximately 3-4 hours.

Contraindications

Hypersensitivity to propoxyphene or acetaminophen
Use in respiratory depression, acute intoxication with alcohol or other CNS depressants.
History of addiction or dependence on opioids.

Precautions

Use cautiously in patients with impaired hepatic or renal function, elderly, or those with a history of addiction. Due to safety concerns, its use has been widely restricted or discontinued in many countries.

Adverse Reactions - Common

Dizziness, drowsiness (Common)
Nausea, vomiting (Common)
Constipation (Common)

Adverse Reactions - Serious

Respiratory depression (Rare)
Cardiac arrhythmias (Rare)
Adverse cardiovascular events (Rare)

Drug-Drug Interactions

CNS depressants (alcohol, sedatives, tranquilizers)
MAO inhibitors
Other opioids

Drug-Food Interactions

Alcohol enhances sedative effects

Drug-Herb Interactions

N/A

Nursing Implications

Assessment: Monitor pain relief, respiratory status, consciousness level.

Diagnoses:

Risk for respiratory depression
Impaired physical mobility due to sedation

Implementation: Administer with food to reduce gastric irritation; monitor vital signs closely.

Evaluation: Assess pain relief, watch for signs of adverse effects, especially respiratory depression.

Patient/Family Teaching

Do not exceed prescribed dose.
Avoid alcohol and CNS depressants.
Report signs of respiratory distress or allergic reactions.
Caution regarding activities requiring alertness.

Special Considerations

Black Box Warnings:

Potential for addiction, abuse, and misuse.

Genetic Factors: Genetic variations can affect metabolism, potentially altering efficacy and risk.

Lab Test Interference: May interfere with certain liver function tests.

Overdose Management

Signs/Symptoms: Respiratory depression, pinpoint pupils, unconsciousness, cyanosis.

Treatment: Administer naloxone for respiratory depression, supportive care, ensure airway patency, monitor vital signs.

Storage and Handling

Storage: Store in a tightly closed container at room temperature, away from moisture, heat, and light.

Stability: Stable under recommended storage conditions.