Human immunodeficiency virus infection unresponsive to highly active antiretroviral therapy: denial of poor medication adherence or recalcitrant infection?

Poor clinical and virologic response to combination antiretroviral therapy for human immunodeficiency virus (HIV) infection may stem from a variety of factors including poor medication adherence, development of drug-resistant HIV strains, drug interactions, efflux pumps, and unfavorable pharmacokinetics. Diagnosing nonadherence to medication is particularly challenging. We present a case of lack of response to antiretroviral therapy in a patient who denied problems with medication adherence. The patient underwent a variety of objective examinations, all of which suggested poor medication adherence was responsible for his nonresponse to antiretrovirals. An approach to evaluating patients for causes of poor response to antiretroviral therapy and nonadherence and implications for clinical practice are discussed.