Pharmacologic‐Based Methods of Adherence Assessment in HIV Prevention

Failure of pre-exposure prophylaxis with daily tenofovir/emtricitabine and the scenario of delayed HIV seroconversion

“…To validate the adherence pattern, dried blood spots (DBS) were tested for tenofovir diphosphate (TFV-DP) and emtricitabine triphosphate (FTC-TP) on day 0, day 10, week 4, and week 18. A threshold of 700 fmol/punch commensurate with 4 doses per week was used as a cumulative dosing marker for evaluating adherence (Brooks and Anderson, 2018). The week 18 level of 685 fmol/punch suggested imperfect adherence in the preceding 2-6 weeks before the blood draw.…”

Battling the HIV/AIDS Epidemic: Triumphs and Barriers

“…Poor medication adherence also impacts the ability to properly evaluate the efficacy of novel therapeutics. In their commentary, Brooks and Anderson raise the issue of poor adherence to daily PrEP and how this has affected efficacy assessments in clinical trials. Pharmacological approaches to evaluate adherence is an important advancement in overcoming this issue.…”

Comparing self-reported medication adherence measures with hair antiretroviral concentration among people living with HIV in Guangxi, China

“…With the desires for objective and accurate measures, researchers employed medication electronic drug monitoring [9], pharmacodynamics responses (e.g., viral load) [10], or antiretroviral concentration in various pharmacokinetic metrics such as plasma [11], saliva [12], urine [13], dried blood spots [14], and hair [15]. However, these measures are often impractical in resource-limited settings because of the high cost and logistic complexities [7,8,16]. Alternatively, researchers have employed various self-reported measures that differ in content (e.g., pill taken or pill missed), response option (e.g., percentage or rating), and recall timeframe (e.g., 3 days or 30 days) to estimate adherence [17][18][19][20].…”