Given the patient's hypertension and current medications, how do hydrochlorothiazide and amlodipine work together to manage the patient's blood pressure?
Hydrochlorothiazide acts by blocking calcium channels, whereas amlodipine acts as a diuretic to reduce blood volume. Hydrochlorothiazide reduces blood volume by promoting diuresis, while amlodipine decreases vascular resistance by inhibiting calcium channels in smooth muscle. Hydrochlorothiazide and amlodipine both primarily decrease vascular resistance through different mechanisms, leading to a synergistic effect. Hydrochlorothiazide increases cardiac output, while amlodipine decreases heart rate, leading to better blood pressure control.