Drug interactions
Isoniazid + Mestranol
Severity: Minor
Isoniazid and Mestranol: minor 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
Mestranol is converted to ethinylestradiol, which is cleared partly by CYP3A4, so isoniazid could slightly raise exposure. Clinical relevance is expected to be small.
What this interaction means in plain words
Isoniazid and Mestranol have a small, usually unimportant interaction. Most people can take both; the pharmacist may still mention it so that any unexpected effect is recognised.
Why it happens
Weak CYP3A4 inhibition by isoniazid may slightly reduce estrogen metabolism.
What to do
No action beyond awareness; reassess if estrogen-related adverse effects appear.
What to ask your pharmacist
- Is there anything I should notice while taking both?
- Do I need to tell my doctor at the next visit?
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Other interactions of Isoniazid
Frequently asked questions
Can I take Isoniazid with Mestranol?
MediHelp rates the interaction as minor. Isoniazid and Mestranol have a small, usually unimportant interaction. Most people can take both; the pharmacist may still mention it so that any unexpected effect is recognised. Mestranol is converted to ethinylestradiol, which is cleared partly by CYP3A4, so isoniazid could slightly raise exposure. Clinical relevance is expected to be small.
How serious is the interaction between Isoniazid and Mestranol?
MediHelp rates it minor, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: No action beyond awareness; reassess if estrogen-related adverse effects appear.
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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