Generic antiretroviral drug use in HIV-infected patients: A cohort study from the French health insurance database

Objective.-This study aimed to estimate the rate of generic users among HIV-infected patients treated by antiretroviral (ARV) drugs potentially substitutable and to determine factors associated with switch from brand to generic ARV in real-life settings in a French region. Methods.-Cohort of HIV-infected patients aged of >= 18 years, exposed to at least one of the generic of lamivudine (3TC-150 mg/300 mg), zidovudine/lamivudine (AZT-200 mg/3TC-150 mg), nevirapine (NVP-200 mg), efavirenz (EFV-600 mg) and those exposed to brand 3TC, AZT/3TC, NVP, EFV, the fixed-dose combination abacavir/lamivudine (ABC/3TC) or the single-tablet regimen efavirenz/emtricitabine/tenofovir (EFV/FTC/TDF) as recorded in the French health insurance database between January 2012 and May 2015 were included. Factors associated with switch (for each generic versus its brand drug; and for situation requiring breaking the combination) were investigated through a logistic regression. Results.-Among the 1539 patients likely to switch from brand ARV drugs, only 165 (11%) were exposed to generics. For EFV users, switch from brand to generic was associated with age (aOR = 1.04 [CI: 1.00-1.08]). For ABC/3TC users, switch was significantly more frequent in patients receiving a monthly average of more than two non-ARV drugs (3.08 [1.42-6.68]) and whose regimen contained a non-nucleoside reverse transcriptase inhibitor (NNRTI) as index medication (3rd agent) (5.68 [2.68-11.39]). By contrast, switch was less frequent in AZT/3TC users exposed to drugs used in digestive disorders (0.39 [0.18-0.88]) or analgesics (0.42 [0.20-0.90]). Conclusion. Treatment-experienced HIV patients whose disease has been stabilized (less comorbidities) are more likely to switch to generic antiretroviral drugs. (C) 2017 Societe francaise de pharmacologie et de therapeutique. Published by Elsevier Masson SAS. All rights reserved.