Lack of interaction between ramipril and simvastatin

Area of Science:

• Pharmacology
• Clinical Pharmacy
• Drug Interactions

Background:

• Ramipril is an ACE inhibitor used to treat hypertension and heart failure.
• Simvastatin is a statin used to lower cholesterol.
• Potential drug interactions between ramipril and simvastatin require investigation.

Purpose of the Study:

• To evaluate the pharmacokinetic interaction between simvastatin and ramipril.
• To assess the impact of simvastatin on the active metabolite ramiprilat.
• To determine if simvastatin affects the ACE-inhibiting activity of ramiprilat.

Main Methods:

• A randomized, placebo-controlled, double-blind, cross-over study was conducted in 22 healthy males.
• Subjects received either simvastatin (20 mg) or placebo daily for 7 days.
• Ramipril (5 mg) was administered on Day 5 of each period, with pharmacokinetic and pharmacodynamic assessments up to 72 hours post-dose.

Main Results:

• Simvastatin did not significantly alter the plasma concentrations (AUC) of ramipril or ramiprilat.
• Urinary excretion of ramipril and its metabolites was comparable between the placebo and simvastatin groups.
• Maximum ACE inhibition was similar, with 94.6% for ramipril+placebo and 94.1% for ramipril+simvastatin.

Conclusions:

• Concomitant administration of simvastatin and ramipril does not produce clinically significant pharmacokinetic interactions.
• Simvastatin does not affect the pharmacodynamic activity (ACE inhibition) of ramipril.
• The combination of simvastatin and ramipril is considered safe in healthy individuals.