Medications and Biotin
Many different drugs have the potential to affect biotin levels. However the investigations to date are small and not very consistent. Some research studies have examined biotin levels others on biotinidase activity (the enzyme that assists in the release of biotin from food and helps release biotin off of used enzymes). Measuring blood levels of biotin is not very accurate because there are many metabolites. The best method is measurement of 3-hydroxyisovaleric acid, an acid that is an indicator of deficiency of a biotin-dependent enzyme. This test is not wide available.
What drugs affect biotin?
Classic medications that appear to lower biotin include oral antibiotics, isotretinoin, and the anticonvulsants (valproic acid, phenytoin, carbemazepine and others). Studies are not consistent. Castro-Gaga and colleagues (see reference below) studied biotin levels in 20 children on valproic acid and 10 on carbemazepine and compared levels to 75 children not on these medications. Biotin and biotinidase levels did not differ between these groups. However, 3 children with hair loss receiving valproic acid grew hair back with biotin supplementation.
Shulpis et al studied 75 children receiving vaproic acid and compared this group to 50 children not on these drugs. Biotinidase activity decreased with valproic acid treatment. In addition, children improved their hair loss with 10 mg per day biotin supplementation.
As I mentioned above, one of the best methods of determining low biotin status is measurement of urinary 3-hydroxyisovaleric acid, an organic acid. Higher levels of 3-hydroxyisovaleric acid indicated biotin deficiency. Mock and colleagues found urinary 3-hydroxyisovaleric acid was increased in those receiving carbemazepine and phenytoin.
Many drugs can affect biotin. One must consider the role of biotin supplementation in patients receiving certain medications.
The influence of valproic acid and carbamazepine treatment on serum biotin and zinc levels and on biotinidase activity.Castro-Gago M, et al. J Child Neurol. 2011.
Low serum biotinidase activity in children with valproic acid mono therapy. Schulpis KH, et al. Epilepsia. 2001.
Disturbances in biotin metabolism in children undergoing long-term anticonvulsant therapy.Mock DM, et al. J Pediatr Gastroenterol Nutr. 1998
Dr. Jeff Donovan is a Canadian and US board certified dermatologist specializing exclusively in hair loss. To schedule a consultation, please call the Whistler office at 604.283.1887