Effects of raltegravir formulation change on medication adherence and medication errors.

This study was aimed at assessing the adherence and incorrect drug intake associated with changes in the dosing schedule of raltegravir, the first integrase strand transfer inhibitor, from 400 mg twice a day (BID) to 600 mg × 2 tablets once a day (QD) in human immunodeficiency virus (HIV)-infected patients. Medication adherence over 1 month was evaluated in 25 male patients using the 100-mm visual analog scale (VAS) at the 3-day recall pill count and during pharmacist counseling after the first post-change visit. VAS scores before and after the raltegravir formulation change were compared. Medication adherence increased from 96 ± 4.3 mm (BID) to 100 ± 0.3 mm (QD) (P < 0.05). The patients exhibited improved medication adherence; however, three patients incorrectly took the drug when the formulation changed. This discovery can be used to facilitate the treatment of HIV-infected patients to increase treatment suitability and safety.