Drug interactions
Butabarbital + Levothyroxine
Severity: Moderate
Butabarbital and Levothyroxine: 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
Barbiturates induce hepatic enzymes and can accelerate levothyroxine clearance. Patients with limited thyroid reserve may become hypothyroid and need a higher dose.
What this interaction means in plain words
Butabarbital and Levothyroxine 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
Barbiturate induction of hepatic glucuronidation and metabolism increases levothyroxine clearance.
What to do
Monitor TSH when a barbiturate is started or stopped and increase the levothyroxine dose if needed.
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 Levothyroxine
Frequently asked questions
Can I take Butabarbital with Levothyroxine?
MediHelp rates the interaction as moderate. Butabarbital and Levothyroxine 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. Barbiturates induce hepatic enzymes and can accelerate levothyroxine clearance. Patients with limited thyroid reserve may become hypothyroid and need a higher dose.
How serious is the interaction between Butabarbital and Levothyroxine?
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 TSH when a barbiturate is started or stopped and increase the levothyroxine dose if needed.
What other medicines interact with Levothyroxine?
MediHelp also lists interactions of Levothyroxine with, for example, Cholestyramine, Sodium iodide i-131, Tiratricol. The full list is on the Levothyroxine page.
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