Drug interactions
Metformin + Trifluoperazine
Severity: Moderate
Metformin and Trifluoperazine: 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
Phenothiazine antipsychotics can cause hyperglycemia and impaired glucose tolerance, which may reduce metformin's effect. The effect is generally modest with trifluoperazine.
What this interaction means in plain words
Metformin and Trifluoperazine 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.
Why it happens
Phenothiazines can reduce insulin secretion and sensitivity, opposing metformin's glucose-lowering action.
What to do
Monitor blood glucose after starting or changing trifluoperazine and adjust metformin 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 Metformin
Frequently asked questions
Can I take Metformin with Trifluoperazine?
MediHelp rates the interaction as moderate. Metformin and Trifluoperazine 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. Phenothiazine antipsychotics can cause hyperglycemia and impaired glucose tolerance, which may reduce metformin's effect. The effect is generally modest with trifluoperazine.
How serious is the interaction between Metformin and Trifluoperazine?
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 after starting or changing trifluoperazine and adjust metformin if control worsens.
What other medicines interact with Metformin?
MediHelp also lists interactions of Metformin with, for example, Contrast media, Diatrizoate meglumine / diatrizoate, Diatrizoate. The full list is on the Metformin page.
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