Drug interactions
Orlistat + Ritonavir
Severity: Moderate
Orlistat and Ritonavir: moderate interaction.
Last updated
For healthcare professionals — reference only. This page is a brief summary, not medical advice and not a substitute for official labeling or clinical judgement. Always verify before prescribing or dispensing.
Summary
Loss of virological control has been reported in HIV-infected patients taking orlistat with antiretroviral regimens including ritonavir, likely from reduced antiretroviral exposure. This could lead to treatment failure and resistance.
What this interaction means in plain words
Orlistat and Ritonavir can affect each other. The combination is often manageable, but it may need a change of dose, a change of timing, or extra checks while both are taken.
Orlistat belongs to Miscellaneous; Ritonavir belongs to Anti Virals.
Why it happens
Orlistat may reduce gastrointestinal absorption of lipophilic antiretrovirals; the exact mechanism is not established.
What to do
Avoid orlistat where possible; if used, monitor HIV RNA frequently and stop orlistat if viral load rises.
What to ask your pharmacist
- Should I take them at different times of day?
- Does the dose of either medicine need to change?
- Is there anything I should avoid, such as alcohol or certain foods, while on both?
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Other interactions of Orlistat
- Cyclosporine + Orlistat Major
- Cyclosporin + Orlistat Major
- Orlistat + Triheptanoin Major
- Amiodarone + Orlistat Moderate
- Beta carotene + Orlistat Moderate
- Carbamazepine + Orlistat Moderate
Other interactions of Ritonavir
- Alfuzosin + Ritonavir Contraindicated
- Amiodarone + Ritonavir Contraindicated
- Avanafil + Ritonavir Contraindicated
- Colchicine + Ritonavir Contraindicated
- Dronedarone + Ritonavir Contraindicated
- Eletriptan + Ritonavir Contraindicated
Frequently asked questions
Can I take Orlistat with Ritonavir?
MediHelp rates the interaction as moderate. Orlistat and Ritonavir can affect each other. The combination is often manageable, but it may need a change of dose, a change of timing, or extra checks while both are taken. Loss of virological control has been reported in HIV-infected patients taking orlistat with antiretroviral regimens including ritonavir, likely from reduced antiretroviral exposure. This could lead to treatment failure and resistance.
How serious is the interaction between Orlistat and Ritonavir?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Avoid orlistat where possible; if used, monitor HIV RNA frequently and stop orlistat if viral load rises.
What other medicines interact with Orlistat?
MediHelp also lists interactions of Orlistat with, for example, Cyclosporine, Cyclosporin, Triheptanoin. The full list is on the Orlistat page.
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