acetaminophen/propoxyphene (Darvocet, Wygesic)

Introduction

DEA-controlled substance: class 4.

Propoxyphene banned by FDA Feb 2009

Indications

management of mild to moderate pain

Contraindications

pregnancy-category C

safety in lactation ?

Dosage

N-50: (50 mg propoxyphene + 325 mg acetaminophen):

• 2 tabs PO every 4 hours.

N-100: (100 mg propoxyphene + 650 mg acetaminophen)*

A-500: (100 mg propoxyphene + 500 mg acetaminophen)*

• 1 tab PO every 4 hours.

Wygesic: (65 mg propoxyphene + 650 mg acetaminophen)

• 1 tab PO every 4 hours.

* 1 A-500 tablet is NOT equal to 5 N-100 tablets!

Pharmacokinetics

elimination: liver

Adverse effects

• not common (1-10%)
  • dizziness, lightheadedness, headache, weakness, sedation, paradoxical excitement & insomnia, rash, GI upset, tolerance, physical & psychologic dependence

• drug adverse effects of opiates
• drug adverse effects of psychotropic agents
• drug adverse effects of sedatives

More general terms

• narcotic combination

Components

• acetaminophen (Tylenol, Paracematol, Panadol, Tempra, Datril, APAP, non-Aspirin)
• propoxyphene (Darvon, Dolene, Proxagesic, Novopropoxyn)

Database

• PubChem: http://pubchem.ncbi.nlm.nih.gov/summary/summary.cgi?cid=123857