Drug interactions
Insulin aspart protamine / insulin aspart + Tolbutamide
Severity: Moderate
Insulin aspart protamine / insulin aspart 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
Combining insulin with a sulfonylurea gives additive glucose lowering and a higher risk of hypoglycemia. This combination is often used deliberately but needs dose adjustment.
What this interaction means in plain words
Insulin aspart protamine / insulin aspart 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.
Why it happens
Additive pharmacodynamic glucose-lowering from exogenous insulin and sulfonylurea-stimulated endogenous insulin secretion.
What to do
Monitor blood glucose frequently and reduce the tolbutamide or insulin dose if hypoglycemia occurs. Educate the patient on recognition and treatment of hypoglycemia.
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 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 Insulin aspart protamine / insulin aspart with Tolbutamide?
MediHelp rates the interaction as moderate. Insulin aspart protamine / insulin aspart 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. Combining insulin with a sulfonylurea gives additive glucose lowering and a higher risk of hypoglycemia. This combination is often used deliberately but needs dose adjustment.
How serious is the interaction between Insulin aspart protamine / insulin aspart 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 frequently and reduce the tolbutamide or insulin dose if hypoglycemia occurs. Educate the patient on recognition and treatment of hypoglycemia.
What other medicines interact with Tolbutamide?
MediHelp also lists interactions of Tolbutamide with, for example, Glyburide-metformin, Insulin degludec-liraglutide, Aceclofenac. The full list is on the Tolbutamide page.
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