Some of the drugs listed below can affect certain functions of the body, resulting in bad side effects. However, drugs that lower blood pressure have proven effective over the years. The benefits of using them far outweigh the risk of side effects. Most people who’ve taken these drugs haven’t had any problems.
Diuretics — Some of these drugs may decrease your body’s supply of a mineral called potassium. Symptoms such as weakness, leg cramps or being tired may result. Eating foods containing potassium may help prevent significant potassium loss. You can prevent potassium loss by taking a liquid or tablet that has potassium along with the diuretic, if your doctor recommends it. Diuretics such as amiloride (Midamar), spironolactone (Aldactone) or triamterene (Dyrenium) are called “potassium sparing” agents. They don’t cause the body to lose potassium. They might be prescribed alone but are usually used with another diuretic. Some of these combinations are Aldactazide, Dyazide, Maxzide or Moduretic.
Some people suffer from attacks of gout after prolonged treatment with diuretics. This side effect isn’t common and can be managed by other treatment. This is because of hyperurecemia caused by diuretics.
In people with diabetes, diuretic drugs may increase the blood sugar level. A change in drug, diet, insulin or oral antidiabetic dosage corrects this in most cases. Your doctor can change your treatment. Most of the time the degree of increase in blood sugar isn’t much. Impotence may also occur in a small percentage of people.
Beta-blockers — Acebutolol (Sectral), atenolol (Tenormin), metoprolol (Lopressor, Mepressor, Merol), nadolol (Corgard), pindolol (Visken), propranolol (Inderal) or timolol (Blocadren) may cause insomnia, cold hands and feet, tiredness or depression, a slow heartbeat or symptoms of asthma. Impotence may occur. If you have diabetes and you’re taking insulin, have your responses to therapy monitored closely.
ACE inhibitors — These drugs, such as captopril (Capoten), enalapril (Vasotec), lisinopril (Zestril or Prinivil), may cause a skin rash; loss of taste; a chronic dry, hacking cough most common side effect; and in rare instances, kidney damage.
Angiotensin II receptor blockers — These drugs may cause occasional dizziness.
Calcium channel blockers — Diltiazem (Cardizem), nicardipine (Cardene), Nifedipine (Procardia) and verapamil (Calan or Isoptin) may cause palpitations, swollen ankles edema, constipation, headache or dizziness. Side effects with each of these drugs differ a great deal.
Alpha blockers — These drugs may cause fast heart rate, dizziness or a drop in blood pressure when you stand up i.e postural hypoteson
Combined alpha and beta blockers — People taking these drugs may experience a drop in blood pressure when they stand up.
Central agonists — Alpha methyldopa (Aldomet) may produce a greater drop in blood pressure when you’re in an upright position (standing or walking) and may make you feel weak or faint if the pressure has been lowered too far. This drug may also cause drowsiness or sluggishness, dryness of the mouth, fever or anemia. Male patients may experience impotence. If this side effect persists, your doctor may have to change the drug dosage or use another medication.
Clonidine (Catapres), guanabenz (Wytensin) or guanfacine (Tenex) may produce severe dryness of the mouth, constipation or drowsiness. If you’re taking any of these drugs, don’t stop suddenly, because your blood pressure may rise quickly to dangerously high levels.
Peripheral adrenergic inhibitors — Reserpine may cause a stuffy nose, diarrhea or heartburn. These effects aren’t severe and no treatment is required other than to change the amount of drugs taken. If you have nightmares or insomnia or get depressed, tell your doctor. You should stop using the drugs.
Guanadrel (Hylorel) or guanethidine (Ismelin) may cause some diarrhea, which may persist in some people. This side effect usually becomes less of a problem if you continue treatment.
These drugs reduce blood pressure more when you stand. Consequently, you may get dizzy and lightheaded and feel weak when you get out of bed in the morning or stand up suddenly. If you notice any of these reactions — and if they persist for more than a minute or two — sit or lie down and either reduce or omit the next dose of the drug. If symptoms continue, contact your doctor.
When you’re taking guanethidine, don’t keep standing in the hot sun or at a social gathering if you begin to feel faint or weak. These activities cause low blood pressure. Male patients may experience impotence. Contact your doctor if this occurs. These drugs are rarely used unless other medications don’t help.
Blood vessel dilators — Hydralzine (Apresoline) may cause headaches, swelling around the eyes, heart palpitations or aches and pains in the joints. Usually none of these symptoms are severe, and most will go away after a few weeks of treatment. Minoxidil (Loniten) is a potent drug that’s usually used only in resistant cases of severe high blood pressure. It may cause fluid retention (marked weight gain) or excessive hair growth.