Zomepirac--aspirin interactions in man

Area of Science:

• Pharmacology
• Drug Interactions
• Clinical Pharmacokinetics

Background:

• Zomepirac and aspirin are commonly used analgesics.
• Understanding their pharmacokinetic interaction is crucial for safe co-administration.

Purpose of the Study:

• To investigate the pharmacokinetic interaction between zomepirac and aspirin in healthy individuals.
• To assess the impact of co-administration on drug concentrations, protein binding, and clearance.

Main Methods:

• A single-dose pharmacokinetic study was conducted in 12 healthy males.
• Participants received zomepirac sodium and aspirin at specified doses and intervals.
• Plasma concentrations and protein binding of both drugs were measured.

Main Results:

• Aspirin decreased zomepirac peak concentration but increased its unbound fraction twofold.
• Zomepirac increased salicylate peak concentration and AUC, while decreasing its clearance.
• Competition for glucuronidation enzymes was suggested as the underlying mechanism.

Conclusions:

• Zomepirac and aspirin exhibit significant pharmacokinetic interactions.
• Increased unbound zomepirac and reduced clearance indicate potential for adverse effects.
• Concomitant therapy with zomepirac and aspirin is not recommended.