Drug interactions
Lycopus + Propylthiouracil
Severity: Moderate
Lycopus and Propylthiouracil: 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
Lycopus (bugleweed) has antithyroid activity and may add to the effect of propylthiouracil, increasing the risk of hypothyroidism. Evidence is limited to traditional use and small studies.
What this interaction means in plain words
Lycopus and Propylthiouracil 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 antithyroid effect through reduced thyroid stimulation and peripheral T4 to T3 conversion.
What to do
Avoid combining the herb with antithyroid drugs unless supervised. Monitor TSH and free T4 if both are used.
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?
Pro+ members
Unlock the full page
Create an account and start a Pro+ trial to unlock the full management advice for Lycopus and Propylthiouracil, the additional notes, the evidence detail and the whole-prescription interaction checker.
- Full clinical management advice
- Additional notes
- Evidence detail
- Interaction checker for a whole prescription
Try Pro+ free for 14 days on the web. No card needed.
Other interactions of Propylthiouracil
Frequently asked questions
Can I take Lycopus with Propylthiouracil?
MediHelp rates the interaction as moderate. Lycopus and Propylthiouracil 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. Lycopus (bugleweed) has antithyroid activity and may add to the effect of propylthiouracil, increasing the risk of hypothyroidism. Evidence is limited to traditional use and small studies.
How serious is the interaction between Lycopus and Propylthiouracil?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Avoid combining the herb with antithyroid drugs unless supervised. Monitor TSH and free T4 if both are used.
What other medicines interact with Propylthiouracil?
MediHelp also lists interactions of Propylthiouracil with, for example, Carbamazepine, Clozapine, Methimazole. The full list is on the Propylthiouracil page.
Full monographs, dosing and an interaction checker in the MediHelp app
Open the complete reference, check multi-drug interactions and use dosing tools in the MediHelp app.
