Drug interactions
Clorazepate + Isoniazid
Severity: Moderate
Clorazepate and Isoniazid: 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
Clorazepate is converted to the active metabolite nordazepam, which is cleared partly by CYP3A4, and isoniazid may slow this clearance. Increased sedation and psychomotor impairment may result, especially in older patients.
What this interaction means in plain words
Clorazepate and Isoniazid 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.
Clorazepate belongs to Central Nervous System; Isoniazid belongs to Anti Bacterial.
Why it happens
Inhibition of CYP3A4 and other oxidative metabolism by isoniazid prolonging benzodiazepine exposure.
What to do
Monitor for excess sedation and reduce the clorazepate dose if needed, particularly in elderly patients. Counsel about driving and alcohol.
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 Isoniazid
Other interactions of Clorazepate
- Calcium / magnesium / potassium / sodium oxybates + Clorazepate Contraindicated
- Clorazepate + Sodium oxybate Contraindicated
- Alfentanil + Clorazepate Major
- Alprazolam + Clorazepate Major
- Amobarbital + Clorazepate Major
- Belladonna and opium + Clorazepate Major
Frequently asked questions
Can I take Clorazepate with Isoniazid?
MediHelp rates the interaction as moderate. Clorazepate and Isoniazid 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. Clorazepate is converted to the active metabolite nordazepam, which is cleared partly by CYP3A4, and isoniazid may slow this clearance. Increased sedation and psychomotor impairment may result, especially in older patients.
How serious is the interaction between Clorazepate and Isoniazid?
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 excess sedation and reduce the clorazepate dose if needed, particularly in elderly patients. Counsel about driving and alcohol.
What other medicines interact with Isoniazid?
MediHelp also lists interactions of Isoniazid with, for example, Bacillus calmette-guerin substrain tice, Benzhydrocodone / acetaminophen, Carbamazepine. The full list is on the Isoniazid page.
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