Objective: To describe the reasons for, and factors associated with, modification and discontinuation of highly active antiretroviral therapy (HAART) regimens at a single clinic.
Subjects: A total of 556 patients who started HAART at the Royal Free Hospital were included in analyses. Modification was defined as stopping or switching any antiretrovirals in the regimen, whereas discontinuation was defined as the simultaneous stopping of all antiretrovirals included in the initial regimen. Reasons were classified as immunological/virological failure (IVF) and toxicities and patient choice/poor compliance (TPC).
Results: The median CD4 count at starting HAART was 171 x 10(6) cells/l and viral load 5.07 log copies/ml. During a median follow-up of 14.2 months, 247 patients (44.4%) modified their HAART regimen, 72 due to IVF (29.1%) and 159 due to TPC (64.4%) and a total of 148 patients (26.6%) discontinued HAART. Older patients were less likely to modify HAART [relative hazard (RH), 0.73 per 10 years; P = 0.0008], as were previously treatment-naive patients (RH, 0.65; P = 0.0050), those in a clinical trial (RH, 0.64; P = 0.027) and those who started nelfinavir (RH, 0.57; P = 0.035). Patients who started with four or more drugs (RH, 2.21, P < 0.0001), who included ritonavir in the initial regimen (RH, 1.41; P = 0.035) or who had higher viral loads during follow-up (RH per log increase, 1.51; P < 0.0001) were more likely to modify HAART.
Conclusions: There was a high rate of modification and discontinuation of HAART regimens in the first 12 months, particularly due to toxicities, patient choice or poor compliance.