Drug Interactions with Indinavir

Introduction to Indinavir and CYP3A4 Inhibition

• Indinavir is classified as a strong CYP3A4 inhibitor and should be avoided in combination with medications primarily metabolized by CYP3A4 due to significant risk of drug interactions that could increase morbidity and mortality, as recommended by the National Comprehensive Cancer Network 1

Clinical Consequences of CYP3A4 Inhibition by Indinavir

• The American College of Cardiology notes that concomitant use of indinavir with ivabradine is contraindicated due to risk of significant bradycardia, with a strength of evidence based on clinical trials 2, 3
• Treatment with nilotinib should be interrupted if systemic administration of indinavir is required, according to the National Comprehensive Cancer Network 1

Guidelines for Prescribing Medications with Indinavir

• When prescribing medications to patients on indinavir, it is recommended to avoid combinations with drugs that are primarily metabolized by CYP3A4, especially those with narrow therapeutic indices, and consider alternatives to CYP3A4 substrates when possible 1

Comparison with Other HIV Protease Inhibitors

• Ritonavir is the most potent CYP3A4 inhibitor, followed by indinavir, and then saquinavir, which has implications for drug interactions and pharmacokinetic boosting 1