Drug interactions
Clonazepam + Ritonavir
Severity: Moderate
Clonazepam 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
Ritonavir can raise clonazepam exposure, increasing sedation, psychomotor impairment and the risk of respiratory depression. The effect is usually more pronounced with sustained dosing and in older or frail patients.
What this interaction means in plain words
Clonazepam 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.
Clonazepam belongs to Central Nervous System; Ritonavir belongs to Anti Virals.
Why it happens
Ritonavir is a potent CYP3A4 inhibitor and reduces the oxidative metabolism of clonazepam.
What to do
Monitor for excessive sedation and respiratory depression when ritonavir is started, and reduce the clonazepam dose if needed. Consider a benzodiazepine less dependent on CYP3A4, such as lorazepam, if the combination is difficult to manage.
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 Clonazepam
- Calcium / magnesium / potassium / sodium oxybates + Clonazepam Contraindicated
- Clonazepam + Sodium oxybate Contraindicated
- Alfentanil + Clonazepam Major
- Alprazolam + Clonazepam Major
- Amobarbital + Clonazepam Major
- Belladonna and opium + Clonazepam Major
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 Clonazepam with Ritonavir?
MediHelp rates the interaction as moderate. Clonazepam 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. Ritonavir can raise clonazepam exposure, increasing sedation, psychomotor impairment and the risk of respiratory depression. The effect is usually more pronounced with sustained dosing and in older or frail patients.
How serious is the interaction between Clonazepam 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: Monitor for excessive sedation and respiratory depression when ritonavir is started, and reduce the clonazepam dose if needed. Consider a benzodiazepine less dependent on CYP3A4, such as lorazepam, if the combination is difficult to manage.
What other medicines interact with Clonazepam?
MediHelp also lists interactions of Clonazepam with, for example, Calcium / magnesium / potassium / sodium oxybates, Sodium oxybate, Alfentanil. The full list is on the Clonazepam page.
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