c. Calcium Channel Blockers. Calcium channel blockers are potent peripheral
vasodilators used in the treatment of hypertension. Similar to beta blockers that can
slow the heart rate, calcium channel blockers are also used in the treatment of atrial
fibrillation to control the heart rate. Many of the products are available in oral and
injectable form and may be administered once daily. Side effects include dizziness,
headache, heartburn, edema, and constipation. Agents include diltiazem (Cardizem,
Tiazac, Dilacor), verapamil (Calan, Isoptin, Covera, Verelan), amlodipine
(Norvasc), felodipine (Plendil), and nifedipine (Procardia XL, Adalat CC).
d. Angiotensin Converting Enzyme Inhibitors (ACE Inhibitors). ACE
inhibitors work by inhibiting the enzyme which converts angiotensin I to angiotensin II.
Angiotensin II is one of the most potent vasoconstrictors known to man. By inhibiting
the enzyme, these agents produce vasodilation and are used in the treatment of
hypertension and heart failure. Most products are administered 1-2 times daily. The
most common side effects are rash, dry cough, and hyperkalemia. These agents are
contraindicated in pregnancy. Selected agents include benazepril (Lotensin), captopril
(Capoten), enalapril (Vasotec), lisinopril (Prinivil, Zestril), and ramipril (Altace).
Enalapril is available in an injectable form.
e. Angiotensin II receptor blockers (ARBs). ARBs work by directly blocking
the angiotensin II receptor to cause vasodilation and lower blood pressure. They
appear to have less side effects than ACE inhibitors, especially the dry cough. Selected
agents include irbesartan (Avapro), losartan (Cozaar), and valsartan (Diovan).
7-11. COMBINATION PRODUCTS
It should be apparent that in order to control hypertension the patient may be
required to take extremely large amounts of medication. In an attempt to develop a
more convenient method of controlling hypertension, researchers have combined
diuretic and antihypertensive agents in order to maximize the best attributes of each.
These combination products are very convenient for the patient to use if the dosage of
the product is exactly what the patient needs to control his hypertension. Since these
combination products tend to be rather expensive, military pharmacies frequently have
a limited selection of these items in stock. Two examples of combination products are
a. Aldactazide (Spironolactone and Hydrochlorothiazide). Spironolactone
and hydrochlorothiazide are both diuretics. This particular drug is used in the treatment
of hypertension, congestive heart failure and cirrhosis of the liver. The patient taking
this medication should be told to take the preparation with or after meals to minimize
b. Dyazide (Triamterene and Hydrochlorothiazide). Triamterene and
hydrochlorothiazide are both diuretics. This product is used as a diuretic and as an