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Drug interactions

Ivermectin + Phenobarbital

Severity: Minor

Ivermectin and Phenobarbital: 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

Phenobarbital induces CYP3A4 and P-glycoprotein and may reduce ivermectin concentrations. This could reduce antiparasitic efficacy, though clinical evidence is limited.

What this interaction means in plain words

Ivermectin and Phenobarbital have a small, usually unimportant interaction. Most people can take both; the pharmacist may still mention it so that any unexpected effect is recognised.

Evidence level: Low

Why it happens

Phenobarbital induces CYP3A4 and P-glycoprotein, increasing ivermectin clearance.

What to do

No empiric dose change is required. Assess treatment response and repeat dosing if cure is not achieved.

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?

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 Ivermectin with Phenobarbital?

MediHelp rates the interaction as minor. Ivermectin and Phenobarbital have a small, usually unimportant interaction. Most people can take both; the pharmacist may still mention it so that any unexpected effect is recognised. Phenobarbital induces CYP3A4 and P-glycoprotein and may reduce ivermectin concentrations. This could reduce antiparasitic efficacy, though clinical evidence is limited.

How serious is the interaction between Ivermectin and Phenobarbital?

MediHelp rates it minor, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: No empiric dose change is required. Assess treatment response and repeat dosing if cure is not achieved.

What other medicines interact with Ivermectin?

MediHelp also lists interactions of Ivermectin with, for example, Erdafitinib, Lasmiditan, Quinidine. The full list is on the Ivermectin page.

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