As the heart pumps blood into the arteries, the blood pushes against the artery walls. Blood pressure measures how forcefully the blood pushes against the artery walls. Systolic pressure, the top number, and diastolic pressure, the bottom one, are the two parts of a blood pressure reading. According to the National Heart Lung and Blood Institute, hypertension (high blood pressure) means the systolic is consistently at 140 or higher or the diastolic is consistently at 90 or higher. If lifestyle changes, such as diet and exercise, cannot control blood pressure then medication becomes necessary.
Diuretics and Beta-blockers
According to HealthScout.com, diuretics and beta-blockers are still the frontline prescription drug therapy for hypertension. Diuretics cause an increase in the removal of salt and water from the body by increasing urine flow. This lowers blood pressure by decreasing blood volume. Hydrochlorothiazide is an example of a prescription diuretic.
Beta-blockers such as propranolol and atenolol control blood pressure by reducing the amount of blood that the heart pumps.
Angiotensin Converting Enzyme (ACE) Inhibitors
The National Heart Lung and Blood Institute describes angiotensin converting enzyme (ACE) inhibitors as drugs that prevent the body from making a hormone called angiotension II. This hormone constricts the arteries, and this constriction makes the heart work harder to pump blood, thereby increasing blood pressure. Blood pressure decreases in patients who take ACE inhibitors because their bodies do not produce angiotensin II. Enalapril and lisinopril are examples of ACE inhibitors.
Calcium-channel Blockers
According to HealthScout.com, calcium-channel blockers such as nifedipine and verapamil relax the muscles in blood vessel walls. This allows the heart to pump blood more easily and blood pressure goes down.
Centrally Acting Drugs
The Mayo Clinic describes centrally acting drugs as medications that "prevent your brain from signaling your nervous system to increase your heart rate and narrow your blood vessels." Clonidine and guanabenz are examples of centrally acting drugs that lower blood pressure, according to HealthScout.com.
