Drug interactions
Metolazone + Tolbutamide
Severity: Moderate
Metolazone and Tolbutamide: 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
Metolazone can raise blood glucose and reduce the effect of tolbutamide. Glycemic control may worsen after the diuretic is started or increased.
What this interaction means in plain words
Metolazone and Tolbutamide 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.
Metolazone belongs to Cardiovascular; Tolbutamide belongs to Endocrine.
Why it happens
Thiazide-like diuretics impair insulin secretion and sensitivity, partly via hypokalemia, opposing sulfonylurea action.
What to do
Monitor blood glucose and potassium when metolazone is started or changed. Adjust the tolbutamide dose if control worsens.
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?
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Other interactions of Metolazone
Other interactions of Tolbutamide
- Glyburide-metformin + Tolbutamide Major
- Insulin degludec-liraglutide + Tolbutamide Major
- Aceclofenac + Tolbutamide Moderate
- Acemetacin + Tolbutamide Moderate
- Acetylsalicylic acid + Tolbutamide Moderate
- Albiglutide + Tolbutamide Moderate
Frequently asked questions
Can I take Metolazone with Tolbutamide?
MediHelp rates the interaction as moderate. Metolazone and Tolbutamide 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. Metolazone can raise blood glucose and reduce the effect of tolbutamide. Glycemic control may worsen after the diuretic is started or increased.
How serious is the interaction between Metolazone and Tolbutamide?
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 when metolazone is started or changed. Adjust the tolbutamide dose if control worsens.
What other medicines interact with Metolazone?
MediHelp also lists interactions of Metolazone with, for example, Amifostine, Amlodipine-hydrochlorothiazide-valsartan, Amlodipine-olmesartan-hydrochlorothiazide. The full list is on the Metolazone page.
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