This class of hypertensive agents lowers blood pressure in several ways. Two of these agents, diltiazem (Cardizem) and verapamil (Calan, Covera HS, Isoptin, Veralan) act in part like the beta blockers, decreasing the vigor of the heart's contractions. They decrease blood pressure by decreasing the force with which blood is pumped into the arteries. These agents also dilate (open up) arteries, decreasing resistance to blood flow, thereby decreasing blood pressure.
The newer calcium channel blockers primarily dilate the arteries and have little effect on the forcefulness of the heart's contractions. These include:
- Amlodipine (Norvasc)
- Felodipine (Plendil)
- Idradipine (DynaCirc)
- Nicardipine (Cardene)
- Nisoldipine (Sular)
Norvasc® has been combined with the cholesterol-lowering drug Lipitor to treat patients with high blood pressure and high cholesterol. This combination drug, which is called Caduet, offers the convenience of taking only one medication to control both conditions.
Calcium channel blockers may have serious side effects and should be used with caution in patients with pulmonary arterial hypertension (PAH). PAH, which is life-threatening, is high blood pressure in the arteries that supply blood to the lungs (the pulmonary arteries).
In some cases, diltiazem and verapamil, which decrease the force of the heart's contractions, worsen congestive heart failure symptoms. Verapamil may occasionally cause constipation, especially in elderly patients. Many of the calcium channel blockers cause headache and edema (swelling) in the ankles and feet.