Drug interactions
Clarithromycin + Isoniazid
Severity: Minor
Clarithromycin and Isoniazid: 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 that may raise clarithromycin concentrations slightly. The clinical relevance appears low, and the two drugs are routinely combined in mycobacterial treatment.
What this interaction means in plain words
Clarithromycin and Isoniazid have a small, usually unimportant interaction. Most people can take both; the pharmacist may still mention it so that any unexpected effect is recognised.
Clarithromycin belongs to Anti Bacterial; Isoniazid belongs to Anti Bacterial.
Why it happens
Isoniazid weakly inhibits CYP3A4 and may reduce clarithromycin clearance.
What to do
No dose change is generally needed; monitor for gastrointestinal upset, hepatotoxicity and QT-related symptoms during therapy.
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?
Pro+ members
Unlock the full page
Create an account and start a Pro+ trial to unlock the full management advice for Clarithromycin and Isoniazid, the additional notes, the evidence detail and the whole-prescription interaction checker.
- Full clinical management advice
- Additional notes
- Evidence detail
- Interaction checker for a whole prescription
Try Pro+ free for 7 days on the web. No card needed.
Other interactions of Clarithromycin
- Astemizole + Clarithromycin Contraindicated
- Avanafil + Clarithromycin Contraindicated
- Cisapride + Clarithromycin Contraindicated
- Clarithromycin + Colchicine Contraindicated
- Clarithromycin + Conivaptan Contraindicated
- Clarithromycin + Dihydroergotamine Contraindicated
Other interactions of Isoniazid
Frequently asked questions
Can I take Clarithromycin with Isoniazid?
MediHelp rates the interaction as minor. Clarithromycin and Isoniazid 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 that may raise clarithromycin concentrations slightly. The clinical relevance appears low, and the two drugs are routinely combined in mycobacterial treatment.
How serious is the interaction between Clarithromycin and Isoniazid?
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 dose change is generally needed; monitor for gastrointestinal upset, hepatotoxicity and QT-related symptoms during therapy.
What other medicines interact with Clarithromycin?
MediHelp also lists interactions of Clarithromycin with, for example, Astemizole, Avanafil, Cisapride. The full list is on the Clarithromycin page.
Full monographs, dosing and an interaction checker in the MediHelp app
Open the complete reference, check multi-drug interactions and use dosing tools in the MediHelp app.
