Drug interactions
Fluvoxamine + Tolbutamide
Severity: Moderate
Fluvoxamine 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
Fluvoxamine can raise tolbutamide levels and prolong its effect, increasing the risk of hypoglycemia. The risk is greatest in older patients and those with impaired renal function or erratic food intake.
What this interaction means in plain words
Fluvoxamine 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.
Fluvoxamine belongs to Central Nervous System; Tolbutamide belongs to Endocrine.
Why it happens
Fluvoxamine inhibits CYP2C9, reducing the metabolism of tolbutamide.
What to do
Monitor blood glucose more frequently when fluvoxamine is started or stopped and lower the tolbutamide dose if hypoglycemia occurs. Teach the patient to recognize hypoglycemia symptoms.
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 Fluvoxamine
- Agomelatine + Fluvoxamine Contraindicated
- Alosetron + Fluvoxamine Contraindicated
- Fezolinetant + Fluvoxamine Contraindicated
- Fluvoxamine + Isocarboxazid Contraindicated
- Fluvoxamine + Mavacamten Contraindicated
- Fluvoxamine + Methylene blue Contraindicated
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 Fluvoxamine with Tolbutamide?
MediHelp rates the interaction as moderate. Fluvoxamine 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. Fluvoxamine can raise tolbutamide levels and prolong its effect, increasing the risk of hypoglycemia. The risk is greatest in older patients and those with impaired renal function or erratic food intake.
How serious is the interaction between Fluvoxamine 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 more frequently when fluvoxamine is started or stopped and lower the tolbutamide dose if hypoglycemia occurs. Teach the patient to recognize hypoglycemia symptoms.
What other medicines interact with Fluvoxamine?
MediHelp also lists interactions of Fluvoxamine with, for example, Agomelatine, Alosetron, Fezolinetant. The full list is on the Fluvoxamine page.
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