Drug interactions
Calcitriol + Phenobarbital
Severity: Moderate
Calcitriol and Phenobarbital: 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
Chronic phenobarbital therapy increases the metabolism of vitamin D compounds and may reduce calcitriol effect. It can contribute to hypocalcemia and bone disease.
What this interaction means in plain words
Calcitriol and Phenobarbital 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
Phenobarbital induces hepatic enzymes, accelerating the catabolism of vitamin D metabolites.
What to do
Monitor serum calcium, phosphate and PTH, and increase calcitriol dose if the response is inadequate.
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 Calcitriol and Phenobarbital, 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 Calcitriol
- Amlodipine-hydrochlorothiazide-valsartan + Calcitriol Moderate
- Amlodipine-olmesartan-hydrochlorothiazide + Calcitriol Moderate
- Amobarbital + Calcitriol Moderate
- Apalutamide + Calcitriol Moderate
- Atazanavir + Calcitriol Moderate
- Atenolol-chlorthalidone + Calcitriol Moderate
Frequently asked questions
Can I take Calcitriol with Phenobarbital?
MediHelp rates the interaction as moderate. Calcitriol and Phenobarbital 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. Chronic phenobarbital therapy increases the metabolism of vitamin D compounds and may reduce calcitriol effect. It can contribute to hypocalcemia and bone disease.
How serious is the interaction between Calcitriol and Phenobarbital?
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 serum calcium, phosphate and PTH, and increase calcitriol dose if the response is inadequate.
What other medicines interact with Calcitriol?
MediHelp also lists interactions of Calcitriol with, for example, Amlodipine-hydrochlorothiazide-valsartan, Amlodipine-olmesartan-hydrochlorothiazide, Amobarbital. The full list is on the Calcitriol 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.
