Drug interactions
Isoniazid + Tolazamide
Severity: Minor
Isoniazid and Tolazamide: 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 can impair glucose tolerance and may worsen glycemic control in diabetic patients. This could blunt the effect of sulfonylureas such as tolazamide, although the effect is inconsistent and generally modest.
What this interaction means in plain words
Isoniazid and Tolazamide 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; Tolazamide belongs to Endocrine.
Why it happens
Isoniazid may cause hyperglycemia or impaired glucose tolerance, opposing the hypoglycemic effect; the mechanism is not well defined.
What to do
Monitor blood glucose when isoniazid is started or stopped in patients taking tolazamide, and adjust the antidiabetic dose if control changes.
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 Isoniazid and Tolazamide, 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 Isoniazid
Other interactions of Tolazamide
- Disopyramide + Tolazamide Major
- Insulin degludec-liraglutide + Tolazamide Major
- Aceclofenac + Tolazamide Moderate
- Acemetacin + Tolazamide Moderate
- Acetylsalicylic acid + Tolazamide Moderate
- Albiglutide + Tolazamide Moderate
Frequently asked questions
Can I take Isoniazid with Tolazamide?
MediHelp rates the interaction as minor. Isoniazid and Tolazamide 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 can impair glucose tolerance and may worsen glycemic control in diabetic patients. This could blunt the effect of sulfonylureas such as tolazamide, although the effect is inconsistent and generally modest.
How serious is the interaction between Isoniazid and Tolazamide?
MediHelp rates it minor, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Monitor blood glucose when isoniazid is started or stopped in patients taking tolazamide, and adjust the antidiabetic dose if control changes.
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.
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.
