Last week, in "The Ups and Downs of Meds and Diabetes (Part 1): Steroids," we took a look at steroids, a powerful class of drugs that, while very good at doing what it’s supposed to do, can cause significant hyperglycemia (high blood glucose). Frequent blood glucose monitoring and using sick-day rules are the best ways to deal with that issue. This week, we’ll look at another category of drugs: hypertension (high blood pressure) medications, since many people with diabetes take these.
There are several classes of hypertension meds, although four of these classes are used most often in diabetes.
ACE Inhibitors: Angiotensin-converting enzyme (ACE) inhibitors are medications that block an enzyme from making angiotensin II. This substance can cause blood vessels to constrict, or narrow, thus raising blood pressure. Common ACE inhibitors include lisinopril (brand names Zestril, Prinivil), enalapril (Vasotec), and captopril (Capoten).
ACE inhibitors are often a first choice for people with diabetes, as they can prevent kidney damage. They also can help people who have heart failure and who have had a heart attack. While these drugs are usually well-tolerated by most people, side effects include dry cough, high potassium levels, dizziness, drowsiness, headache, and altered taste. ACE inhibitors have little effect on blood glucose levels. However, your health-care provider needs to monitor your potassium levels to make sure they stay in a safe range.
ARBs: Angiotensin-II receptor blockers (ARBs, for short) work in a manner similar to ACE inhibitors. They may be prescribed for someone who doesn’t tolerate ACE inhibitors, as they produce less of a cough. ARBs may also provide more protection for the kidneys. Commonly prescribed ARBs include candesartan (Atacand), irbesartan (Avapro), losartan (Cozaar), and valsartan (Diovan). Side effects are pretty much the same as with ACE inhibitors, with the exception of coughing. Again, potassium levels need to be monitored while taking an ARB.
Beta-Blockers: Beta-blockers (beta-adrenergic blocking agents) lower blood pressure by blocking the effects of epinephrine, or adrenaline. Because they do so, the heart beats more slowly and less forcefully, which, in turn, lowers blood pressure. Beta-blockers also cause blood vessels to relax, which improves blood flow.
While beta-blockers lower blood pressure, they’re also used to treat or improve other conditions, such as arrhythmias, heart failure, heart attack, angina, migraines, glaucoma, and even anxiety. Commonly prescribed beta blockers include atenolol (Tenormin), metoprolol (Lopressor, Toprol XL), propranolol (Inderal), and nadolol (Corgard). Fatigue, cold hands and feet, dizziness, weakness, insomnia, weight gain, shortness of breath, and slow heartbeat are typical side effects.
Also, beta-blockers should be used with caution in people with diabetes. These medications may mask, or hide, the symptoms of low blood glucose. And this is a concern if you take insulin or certain types of diabetes pills that can cause hypoglycemia. If you take a beta-blocker, make sure you check your blood glucose levels frequently, especially if you’re at risk for hypoglycemia.
Calcium Channel Blockers: Calcium channel blockers (CCBs) work to block calcium from entering the cells of the heart and blood vessels. This action helps to lower blood pressure. These medications are also used to treat angina, arrhythmias, and migraines. Nifedipine (Adalat, Procardia), verapamil (Calan, Covera), and amlodipine (Norvasc, Lotrel) are common calcium channel blockers. Side effects include constipation, edema, headache, rapid heartbeat, drowsiness, and rash. Some CCBs shouldn’t be taken with grapefruit juice, as the juice may block the liver from excreting the medication. CCBs may interact with metformin, rosiglitazone (Avandia), and pioglitazone (Actos), so talk to your health-care provider or pharmacist if you take any of these drugs for your diabetes.
Diuretics: Diuretics, often called “water pills,” work to lower blood pressure by causing the body to flush out extra fluid and sodium. There are several kinds of diuretics and they all work somewhat differently. Furosemide (Lasix), bumetanide (Bumex), spironolactone (Aldactone), and hydrochlorothiazide (Esidrix) are common types of diuretics. Side effects include increased urination, fatigue, weakness, dizziness, impotence, increased triglycerides, and, with some diuretics, decreased potassium levels. High doses of diuretics may lead to increased blood glucose levels—again, blood glucose monitoring is important if you take diuretics.
Next week: Lipid-lowering medications.