A 65-year-old man with severe hypertension has not achieved his therapeutic goal for controlling his blood pressure after treatment with a combination of 4 different antihypertensive drugs for the past 6 months. Having exhausted the list of the most highly recommended drugs, his physician elects to add reserpine to his drug regimen, since it has a unique mechanism of action, and remains as a therapeutic option based upon the consensus of expert opinions for treatment of hypertension.