Drug interactions
Chlorthalidone + Gliclazide
Severity: Moderate
Chlorthalidone and Gliclazide: 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
Thiazide-type diuretics such as chlorthalidone can raise blood glucose and reduce the effect of gliclazide, particularly at higher doses. Hypokalemia may further impair insulin secretion.
What this interaction means in plain words
Chlorthalidone and Gliclazide 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.
Chlorthalidone belongs to Cardiovascular; Gliclazide belongs to Endocrine.
Why it happens
Pharmacodynamic antagonism via thiazide-induced hypokalemia, reduced insulin release and decreased insulin sensitivity.
What to do
Monitor blood glucose and potassium, and adjust the antidiabetic regimen if control worsens. Use the lowest effective chlorthalidone dose.
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?
Pro+ members
Unlock the full page
Create an account and start a Pro+ trial to unlock the full management advice for Chlorthalidone and Gliclazide, 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 Gliclazide
Other interactions of Chlorthalidone
Frequently asked questions
Can I take Chlorthalidone with Gliclazide?
MediHelp rates the interaction as moderate. Chlorthalidone and Gliclazide 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. Thiazide-type diuretics such as chlorthalidone can raise blood glucose and reduce the effect of gliclazide, particularly at higher doses. Hypokalemia may further impair insulin secretion.
How serious is the interaction between Chlorthalidone and Gliclazide?
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 blood glucose and potassium, and adjust the antidiabetic regimen if control worsens. Use the lowest effective chlorthalidone dose.
What other medicines interact with Gliclazide?
MediHelp also lists interactions of Gliclazide with, for example, Ciprofloxacin, Clarithromycin, Disopyramide. The full list is on the Gliclazide 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.
