Switching from twice‐daily abacavir and lamivudine to the once‐daily fixed‐dose combination tablet of abacavir and lamivudine improves patient adherence and satisfaction with therapy

Background Patients prefer fewer pills and once‐daily (qd) dosing without food restrictions. We assessed the impact on adherence [by Medication Event Monitoring System (MEMS) cap monitoring] of switching from abacavir (ABC) and lamivudine (3TC) twice daily (bid) to ABC/3TC fixed‐dose formulation (FDC, Kivexa ® ) qd to achieve a qd regimen. Methods A randomized, open‐label, 8‐week study comparing adherence, efficacy and safety of immediate vs . delayed switching from ABC/3TC to FDC qd. Results Ninety‐four patients were dosed. Significantly improved adherence was observed at week 4 with qd ABC/3TC across all three adherence variables: taking compliance 99.2% (90.7–100%) vs . 96.6% (60.0–100%) ( P =0.017); dosing compliance 97.1% (64.3–100%) vs . 91.9% (33.3–100%) ( P =0.016); and timing compliance 95.5% (53.8–100%) vs . 86.3% (4.3–100%) ( P =0.006). Treatment satisfaction increased significantly at week 4 with ABC/3TC qd [92% (82–99%) vs . 85% (75–93%) ( P =0.004)]. Two patients were withdrawn from the study because of intolerance to ABC/3TC. Conclusions Switching from ABC and 3TC bid to ABC/3TC FDC qd significantly improved adherence by MEMS cap monitoring at week 4 and improved patient satisfaction with therapy. The results remain to be confirmed over a longer follow‐up. Use of qd regimens supports adherence and improves treatment satisfaction relative to bid regimens.