Risk of valproic acid-related alopecia: A systematic review and meta-analysis

We systematically reviewed studies to provide current evidence about the incidence and risk of alopecia in patients undergoing valproic acid (VPA) therapy.

We retrieved relevant publications and gathered data on alopecia in patients taking VPA and other drugs from prospective studies.

Twenty-five articles met the inclusion criteria, and the overall incidence of alopecia in patients receiving VPA therapy was 11% (95% confidence interval (CI): 0.08-0.13). The pooled risk of alopecia showed a significant difference between patients treated with VPA and all other drugs (odds ratio (OR) 5.02, 95% CI: 3.58-7.03), other epileptic drugs (AEDs) (OR 4.82, 95% CI: 3.32-7.00) and other non-AEDs (OR 5.84, 95% CI: 2.67-12.81). Compared to other drugs, VPA increased the risk of alopecia both in patients with migraine headaches (OR 6.05, 95% CI: 2.89-12.63) and patients with epilepsy (OR 5.29, 95% CI: 3.53-7.92), and the increase risk was reported more frequently in patients with migraine. Both lower doses (OR 4.38, 95% CI: 2.32-8.25) and shorter treatments (OR 4.98, 95% CI: 2.41-10.25) with VPA posed a high risk of alopecia compared to other drugs, as did higher doses and longer treatment times.

Based on our findings, VPA was significantly associated with a risk of alopecia compared to other drugs, and the risk did not depend on the dose and treatment time.