One of the principal challenges in managing hypertension is suboptimal medication adherence, which can result in up to 50 % of patients experiencing pseudo-resistant hypertension and inadequate blood pressure control. The intricate nature of antihypertensive regimens, the high cost of therapy, the prevalence of numerous adverse effects and the therapeutic inertia commonly lead to inconsistent drug use and premature discontinuation of treatment. Consequently, nonadherence significantly elevates the risk of cardiovascular events.

Drug concentrations in the patient's serum or urine (also known as therapeutic drug monitoring, or TDM) and blood pressure measurements following supervised medication ingestion are two techniques for assessing treatment adherence. In alignment with guideline from the Food and Drug Administration (FDA) and European Medicines Agency (EMA), this study aims to design, develop, and validate a single UHPLC method for the plasma quantification of five antihypertensive drugs within the calcium channel blocker class: amlodipine, nifedipine, barnidipine, lercanidipine and lacidipine.