Cerebrospinal Fluid Abacavir Concentrations in HIV-positive Patients Following Once-daily Administration

Abacavir is a widely used nucleotide reverse transcriptase inhibitor whose cerebrospinal fluid (CSF) exposure has been previously assessed in twice-daily recipients. We studied abacavir CSF concentrations in 61 and 9 HIV-positive once-daily and twice-daily abacavir intakers. Patients on once-daily abacavir had higher plasma and CSF concentrations (96 vs. 22 ng/mL, p=0.038 and 123 vs. 49 ng/mL, p=0.038) but similar CSF-to-plasma ratios (0.8 vs. 0.5, p=0.500). CSF abacavir concentrations were adequate in once-daily receiving patients.