IntroductionMedication nonadherence leads to poor health outcomes, frequent complications, and high economic impact. Our objective was to assess the determinants of adherence to medication regimens among patients with hypertension.MethodsWe conducted a cross-sectional study of patients with hypertension attending the cardiology clinic of a tertiary care hospital in Islamabad, Pakistan. Data were collected by using semistructured questionnaires. A score of 7 or 8 on the 8-item Morisky Medication Adherence Scale was classified as good adherence, 6 as moderate, and less than 6 as nonadherence. Logistic regression was performed to determine covariates associated with medication adherence.ResultsWe enrolled 450 patients with hypertension (mean age, 54.5 y; SD, 10.6). Medication adherence was good among 115 (25.6%) patients and moderate among 165 (36.7%); 170 (37.8%) patients were nonadherent. Most patients (72.7%) had uncontrolled hypertension. Nearly half (49.6%) were unable to afford monthly medication. In bivariate analysis, nonadherence was associated with female sex (odds ratio [OR], 1.44;P= .003) and long waiting times in the health care facility (OR, 2.93;P= .005); the presence of comorbidities (OR, 0.62;P= .01) was associated with good adherence. In multivariate analysis, nonadherence was associated with unaffordability of treatment (OR, 2.25;P= .002) and uncontrolled hypertension (OR, 3.16;P< .001). Good adherence determinants included adequate counseling (OR, 0.29;P< .001) and education (OR, 0.61;P= .02).ConclusionAddressing identified barriers, including medication affordability and patient counseling, should be included in Pakistan’s national policy on noncommunicable disease.