Objectives Hypertension is among the leading causes of cardiovascular disease worldwide. No previous studies have examined specifically the types of drug-related problems (DRPs) in patients with hypertension, and how these problems affect blood pressure control. So, the primary aim of this study was to investigate the prevalence and nature of DRPs in outpatients with hypertension and reveal any associations between DRPs and blood pressure control in these patients.

Methods This was a cross-sectional correlation study. A total of 200 patients who fulfilled the inclusion criteria were recruited through outpatient clinics. Patients’ data were assessed to identify DRPs using a systematic evidence-based approach.

Results Two hundred participants were recruited in this cross-sectional study. About half of the participants (48.5%) had uncontrolled hypertension. The average number of DRPs was 6.31±2.63. The main identified DRPs affecting blood pressure control included patients’ lack of knowledge about their medications, lack of adherence to their medications, suboptimal efficacy of medications prescribed and the need for additional monitoring. Logistic regression analysis was performed to identify the most important predictors, and significant associations were found between poor blood pressure control and the above-identified variables except for knowledge about medication (p≤0.05).

Conclusion The number of DRPs among patients with hypertension is relatively high. These DRPs were associated with poor blood pressure control. The implementation of clinical pharmacy services for all patients with hypertension is strongly recommended.