Drug interactions
Clozapine + Metformin
Severity: Minor
Clozapine and Metformin: 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
Clozapine often causes weight gain and hyperglycemia, which can reduce the glycemic benefit of metformin. Metformin is also used to counter clozapine-related metabolic effects, so the combination is often intentional.
What this interaction means in plain words
Clozapine and Metformin have a small, usually unimportant interaction. Most people can take both; the pharmacist may still mention it so that any unexpected effect is recognised.
Clozapine belongs to Central Nervous System; Metformin belongs to Endocrine.
Why it happens
Clozapine-induced insulin resistance opposes metformin's glucose-lowering effect.
What to do
Monitor fasting glucose, HbA1c and weight, and titrate metformin as needed. Reassess if clozapine dose 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?
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Other interactions of Clozapine
- Clozapine + Deferiprone Contraindicated
- Clozapine + Irinotecan Contraindicated
- Clozapine + Pimozide Contraindicated
- Clozapine + Thioridazine Contraindicated
- Acalabrutinib + Clozapine Major
- Adagrasib + Clozapine Major
Other interactions of Metformin
Frequently asked questions
Can I take Clozapine with Metformin?
MediHelp rates the interaction as minor. Clozapine and Metformin have a small, usually unimportant interaction. Most people can take both; the pharmacist may still mention it so that any unexpected effect is recognised. Clozapine often causes weight gain and hyperglycemia, which can reduce the glycemic benefit of metformin. Metformin is also used to counter clozapine-related metabolic effects, so the combination is often intentional.
How serious is the interaction between Clozapine and Metformin?
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 fasting glucose, HbA1c and weight, and titrate metformin as needed. Reassess if clozapine dose changes.
What other medicines interact with Clozapine?
MediHelp also lists interactions of Clozapine with, for example, Deferiprone, Irinotecan, Pimozide. The full list is on the Clozapine page.
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