These inhibit formation of the hormone angiotensin II, which causes blood vessels to narrow, thus increasing blood pressure. Calcium channel blockers. These prevent calcium from entering the muscle cells of the heart and blood vessels, thus relaxing blood vessels and decreasing blood pressure. These combine the actions of alpha blockers, which relax blood vessels, and beta blockers, which slow the heartbeat. Often, combinations of two drugs from different classes are used to improve the drugs' effectiveness.
Many doctors begin newly diagnosed hypertensive patients with diuretics or beta blockers.
For hypertensive people with diabetes or kidney disease, the guidelines recommend that initial drug treatments include ACE inhibitors. Patients who begin a drug treatment and develop symptoms that they did not have before should discuss them with their doctors. With the great variety of medicines, it is likely that another antihypertensive drug or dosage level can help control blood pressure with few or no side effects. In my mother's 30-year history of high blood pressure, she's switched drugs only a few times or varied the dosages, mainly to gain better control of her blood pressure. But she's never had any qualms about taking the medicine.