de Jager RL, et al. – The scientists screened antihypertensive agents in serum, to determine the possible determinants of non–adherence in treatment resistant hypertension. Objective measurement of blood pressure (BP) lowering drugs in serum, as a tool to assess adherence, displayed that non–adherence was very common in patients with apparent resistant hypertension. These findings provided a direct and objective methodology which would aid the physician to understand and to improve the condition of apparent resistant hypertension.