[Vitamin D and drugs]

Area of Science:

• Pharmacology
• Endocrinology
• Drug Metabolism

Background:

• Drug-vitamin D interactions are underappreciated in clinical practice.
• The growing number of prescribed medications necessitates a focus on these interactions.
• These interactions can significantly affect patient health and therapeutic outcomes.

Purpose of the Study:

• To highlight the clinical relevance of drug-vitamin D interactions.
• To underscore the importance of considering these interactions in patient care.
• To review mechanisms by which drugs affect vitamin D and bone metabolism.

Main Methods:

• Review of existing literature on drug-vitamin D interactions.
• Discussion of the role of the pregnane X receptor (PXR) in drug-induced vitamin D deficiency.
• Examination of how vitamin D supplementation can influence drug efficacy.

Main Results:

• Certain drugs activate the pregnane X receptor (PXR), increasing CYP24 expression and vitamin D catabolism, potentially causing deficiency.
• Examples of PXR-activating drugs include antiepileptics, taxol, rifampicin, and HIV protease inhibitors (ritonavir, saquinavir).
• Vitamin D supplementation can modify the effects of various medications, including bisphosphonates, statins, and cytostatic drugs.

Conclusions:

• Physicians and pharmacists must increase awareness and attention to drug-vitamin D interactions.
• Understanding these interactions is crucial for optimizing patient treatment and preventing adverse effects.
• Both drug-induced vitamin D deficiency and vitamin D's impact on drug action require careful consideration.