Drug interactions
Chlordiazepoxide + Fosamprenavir
Severity: Major
Chlordiazepoxide and Fosamprenavir: major 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
Fosamprenavir (as amprenavir) inhibits CYP3A4 and can raise chlordiazepoxide exposure. This may lead to excessive sedation, confusion and respiratory depression, especially in older patients or with long-term use.
What this interaction means in plain words
Chlordiazepoxide and Fosamprenavir can interact in a way that may be serious. Using them together is sometimes necessary, but it needs a deliberate decision by the prescriber, a plan for monitoring, and clear advice on the warning signs to watch for.
Why it happens
Inhibition of CYP3A4-mediated metabolism of chlordiazepoxide by amprenavir, the active metabolite of fosamprenavir.
What to do
Prefer a benzodiazepine not dependent on oxidative metabolism, such as lorazepam, or reduce the chlordiazepoxide dose. Monitor for oversedation and respiratory depression.
What to ask your pharmacist
- Does the benefit of taking both outweigh the risk in my case?
- Do I need any blood test, ECG or other check while on both?
- What early warning signs should I watch for, and what should I do if they appear?
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Other interactions of Chlordiazepoxide
Frequently asked questions
Can I take Chlordiazepoxide with Fosamprenavir?
MediHelp rates the interaction as major. Chlordiazepoxide and Fosamprenavir can interact in a way that may be serious. Using them together is sometimes necessary, but it needs a deliberate decision by the prescriber, a plan for monitoring, and clear advice on the warning signs to watch for. Fosamprenavir (as amprenavir) inhibits CYP3A4 and can raise chlordiazepoxide exposure. This may lead to excessive sedation, confusion and respiratory depression, especially in older patients or with long-term use.
How serious is the interaction between Chlordiazepoxide and Fosamprenavir?
MediHelp rates it major, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Prefer a benzodiazepine not dependent on oxidative metabolism, such as lorazepam, or reduce the chlordiazepoxide dose. Monitor for oversedation and respiratory depression.
What other medicines interact with Chlordiazepoxide?
MediHelp also lists interactions of Chlordiazepoxide with, for example, Alfentanil, Alprazolam, Amobarbital. The full list is on the Chlordiazepoxide page.
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