Drug interactions
Calcifediol + Efavirenz
Severity: Minor
Calcifediol and Efavirenz: 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
Efavirenz induces CYP enzymes that break down vitamin D metabolites, and can lower calcifediol levels. Bone mineral loss and vitamin D deficiency are possible with long-term use.
What this interaction means in plain words
Calcifediol and Efavirenz have a small, usually unimportant interaction. Most people can take both; the pharmacist may still mention it so that any unexpected effect is recognised.
Calcifediol belongs to Musculoskeletal; Efavirenz belongs to Anti Virals.
Why it happens
Enzyme induction increases catabolism of vitamin D metabolites.
What to do
Monitor serum 25-hydroxyvitamin D and calcium. Increase calcifediol dose if levels stay low.
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?
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Other interactions of Efavirenz
- Cobimetinib + Efavirenz Contraindicated
- Dienogest / estradiol valerate + Efavirenz Contraindicated
- Dihydroergotamine intranasal + Efavirenz Contraindicated
- Dihydroergotamine + Efavirenz Contraindicated
- Doravirine + Efavirenz Contraindicated
- Efavirenz + Elbasvir / grazoprevir Contraindicated
Other interactions of Calcifediol
- Amlodipine-hydrochlorothiazide-valsartan + Calcifediol Moderate
- Amlodipine-olmesartan-hydrochlorothiazide + Calcifediol Moderate
- Amobarbital + Calcifediol Moderate
- Atenolol-chlorthalidone + Calcifediol Moderate
- Azilsartan-chlorthalidone + Calcifediol Moderate
- Calcifediol + Candesartan-hydrochlorothiazide Moderate
Frequently asked questions
Can I take Calcifediol with Efavirenz?
MediHelp rates the interaction as minor. Calcifediol and Efavirenz have a small, usually unimportant interaction. Most people can take both; the pharmacist may still mention it so that any unexpected effect is recognised. Efavirenz induces CYP enzymes that break down vitamin D metabolites, and can lower calcifediol levels. Bone mineral loss and vitamin D deficiency are possible with long-term use.
How serious is the interaction between Calcifediol and Efavirenz?
MediHelp rates it minor, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Monitor serum 25-hydroxyvitamin D and calcium. Increase calcifediol dose if levels stay low.
What other medicines interact with Efavirenz?
MediHelp also lists interactions of Efavirenz with, for example, Cobimetinib, Dienogest / estradiol valerate, Dihydroergotamine intranasal. The full list is on the Efavirenz page.
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