For hypertension that isn't controlled by diet and exercise, drug therapy usually begins with a diuretic or a beta blocker. It is also sometimes necessary for a doctor to prescribe different medications until the one that is best for you is found. Doctors tend to be more aggressive in using high blood pressure medications in persons with diabetes, kidney disease, or cardiovascular problems. If the first drug doesn't have intolerable side effects, but it also doesn't lower blood pressure enough, then a second type of drug can be added. It is not unusual for people with hypertension to be taking two or even more drugs from different classes.
Many drug classes work synergistically to better control blood pressure.
Oral vasodilators, such as hydralazine and minoxidil, are often used together with a diuretic and other drugs that reduce fluid retention. Clonidine, another type of antihypertensive may also be utilized. After hypertension has been controlled for at least one year, medications may be adjusted. The goal is to maintain blood pressure control using the lowest doses of the least number of medications possible. The key though is to keep blood pressure at or under goal.