Ritonavir
Ritonavir is an antiretroviral protease inhibitor medication primarily used as a pharmacokinetic booster for other HIV protease inhibitors. It works by inhibiting the CYP3A enzyme, which increases plasma concentrations of co-administered antivirals like lopinavir, allowing for more effective HIV suppression. Ritonavir is always used in combination with other antiretroviral agents as part of combination therapy for HIV-1 infection.
Ritonavir is an HIV protease inhibitor mainly used as a booster to increase effectiveness of other antiretroviral drugs.
Key facts at a glance
- ATC
- J05AE03
- RxNorm
- 85762
- Generic
- Ritonavir
- Class
- atc-j05
- Brands
- Norvir, Kaletra
- Availability
- rx
- Lactation
- unknown
- Routes
- oral
- Forms
- tablet, capsule, solution, powder
- Regions
- US, EU, CN, JP
- Monitoring
- —
This page is for informational purposes only.
Do not use this information to diagnose yourself or to replace a physician's advice. Always consult a qualified healthcare provider before starting, stopping, or changing any medication. If you believe you are experiencing a medical emergency, call your local emergency number immediately.
Ritonavir is indicated for the treatment of HIV-1 infection in combination with other antiretroviral agents. While it has inherent anti-HIV activity as a protease inhibitor, it is most commonly prescribed as a pharmacokinetic enhancer for other protease inhibitors.
Ritonavir inhibits the CYP3A-mediated metabolism of co-administered drugs, particularly lopinavir and other protease inhibitors. By blocking this cytochrome P450 enzyme, it increases plasma concentrations and prolongs the half-life of partner medications, enhancing their antiviral effect.
Ritonavir must always be used as part of combination antiretroviral therapy, never as monotherapy. It has numerous drug interactions due to CYP3A inhibition and may cause gastrointestinal side effects. Liver function monitoring is recommended. Dosing varies based on the co-administered medication and formulation used.
Official drug label
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This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.
If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.
Medically reviewed by WellAlly Editorial Team Last reviewed July 26, 2026. · Read our editorial policy