Drug interactions
Isoniazid + Tamsulosin
Severity: Minor
Isoniazid and Tamsulosin: 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
Isoniazid has weak CYP3A4 inhibitory activity and might slightly increase tamsulosin exposure. A clinically meaningful effect is not well documented.
What this interaction means in plain words
Isoniazid and Tamsulosin have a small, usually unimportant interaction. Most people can take both; the pharmacist may still mention it so that any unexpected effect is recognised.
Isoniazid belongs to Anti Bacterial; Tamsulosin belongs to Genitourinary.
Why it happens
Isoniazid weakly inhibits CYP3A4, possibly reducing tamsulosin metabolism.
What to do
No routine change is required; ask the patient to report dizziness or lightheadedness on standing.
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 Tamsulosin
- Alfuzosin + Tamsulosin Major
- Avanafil + Tamsulosin Major
- Ceritinib + Tamsulosin Major
- Clarithromycin + Tamsulosin Major
- Cobicistat + Tamsulosin Major
- Doxazosin + Tamsulosin Major
Other interactions of Isoniazid
Frequently asked questions
Can I take Isoniazid with Tamsulosin?
MediHelp rates the interaction as minor. Isoniazid and Tamsulosin have a small, usually unimportant interaction. Most people can take both; the pharmacist may still mention it so that any unexpected effect is recognised. Isoniazid has weak CYP3A4 inhibitory activity and might slightly increase tamsulosin exposure. A clinically meaningful effect is not well documented.
How serious is the interaction between Isoniazid and Tamsulosin?
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 routine change is required; ask the patient to report dizziness or lightheadedness on standing.
What other medicines interact with Tamsulosin?
MediHelp also lists interactions of Tamsulosin with, for example, Alfuzosin, Avanafil, Ceritinib. The full list is on the Tamsulosin page.
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