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Drug interactions

Phenelzine + Tolazamide

Severity: Moderate

Phenelzine and Tolazamide: 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

MAO inhibitors can enhance the blood glucose-lowering effect of sulfonylureas. Adding phenelzine to tolazamide may therefore precipitate hypoglycemia, which can be prolonged.

What this interaction means in plain words

Phenelzine and Tolazamide 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.

Phenelzine belongs to Central Nervous System; Tolazamide belongs to Endocrine.

Evidence level: Moderate

Why it happens

MAO inhibitors may enhance insulin secretion or sensitivity and alter glucose homeostasis, producing an additive hypoglycemic effect; the exact mechanism is not fully established.

What to do

Monitor blood glucose closely when phenelzine is started, changed or stopped, and reduce the sulfonylurea dose if hypoglycemia occurs. Teach patients 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?

Bring a full list of your medicines, including over-the-counter products, supplements and herbal remedies, to every pharmacy visit.

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Frequently asked questions

Can I take Phenelzine with Tolazamide?

MediHelp rates the interaction as moderate. Phenelzine and Tolazamide 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. MAO inhibitors can enhance the blood glucose-lowering effect of sulfonylureas. Adding phenelzine to tolazamide may therefore precipitate hypoglycemia, which can be prolonged.

How serious is the interaction between Phenelzine and Tolazamide?

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 closely when phenelzine is started, changed or stopped, and reduce the sulfonylurea dose if hypoglycemia occurs. Teach patients to recognize hypoglycemia symptoms.

What other medicines interact with Phenelzine?

MediHelp also lists interactions of Phenelzine with, for example, 5-HTP, Amitriptyline, Amoxapine. The full list is on the Phenelzine page.

Full monographs, dosing and an interaction checker in the MediHelp app

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