Safety of short‐term valacyclovir as an anti‐sickling agent in sickle‐cell anemia

To assess safety and tolerability, we administered valacyclovir, an oral anti‐viral medication that inhibits erythrocyte sickling in vitro, to 14 subjects with sickle‐cell anemia for 1 week at a standard dose of 1,000 mg every 8 hr. No clinically significant adverse effects occurred. In 11 subjects in steady state, the mean hemoglobin concentration was almost constant while the absolute reticulocyte count decreased in eight ( P  = 0.1) and the overall mean fell slightly although not significantly (10%, P  = 0.2). These results suggest that valacyclovir is safe and well tolerated in patients with sickle‐cell anemia and that a longer duration of therapy merits investigation. Pediatr Blood Cancer 2011;56:843–845. © 2011 Wiley‐Liss, Inc.