The Rule on Blood Pressure Meds: Stick to Your Doctor's Orders

Blood pressure medications can be lifesavers. But they can also lead to side effects, complicating the adoption of any blood pressure drug regimen. And if someone accidentally or intentionally takes more medication than they're supposed to, the result could be dangerous.

"Any time you take any medication, you are at risk for having side effects," says Willie E. Lawrence Jr., MD, preventive cardiologist and chief medical officer for the Cardiac and Vascular Interventional Group in Dallas. "That's always a possibility."

Common Side Effects of Blood Pressure Medications

Even when taken exactly as prescribed, blood pressure drugs can sometimes trigger the following adverse effects:

• Weakness

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• Fatigue
• Dizziness
• Fainting
• A dry cough
• Diarrhea

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• Constipation
• Nervousness
• Headaches
• Nausea
• Skin rash
• Erection problems
• Weight changes

That being said, not everyone will experience all, or even any, side effects. Safe use of medications can reduce your risk of side effects.

Side Effects by Drug Class

The various kinds of blood pressure drugs carry different risks.

Diuretics

Examples include these forms:

• chlorthalidone (HemiClor, Hygroton)
• chlorothiazide
• hydrochlorothiazide (Esidrix)
• indapamide (Lozol)
• metolazone (such as Mykrox)

Beta-Blockers

These drugs lower blood pressure by blocking the effects of epinephrine, also known as adrenaline. This reduces your heart rate and blood output.

Side effects of beta-blockers might include the following:

• Insomnia
• Depression
• Cold hands and feet
• Erectile dysfunction

Examples include the following drugs:

• acebutolol
• atenolol (Tenormin)
• metoprolol (Lopressor)
• bisoprolol (Zebeta)

ACE Inhibitors

• Chronic cough
• A skin rash
• Loss of taste
• Dizziness
• Fainting
• Kidney damage

Examples of ACE inhibitors include the following:

• benazepril hydrochloride (Lotensin)
• captopril (Capoten)
• enalapril maleate (Vasotec)
• fosinopril sodium (Monopril)

Calcium Channel Blockers

• amlodipine besylate (Norvasc)
• diltiazem hydrochloride (Cardizem CD, Cardizem SR)
• felodipine (Plendil)
• isradipine (DynaCirc)

The Dangers of Incorrect Dosing

But Gregg Fonarow, MD, director of the Ahmanson-UCLA Cardiomyopathy Center, cautions that "excess dosing of blood-pressure-lowering medications can lower blood pressure and cause symptoms like dizziness or passing out. And if blood pressure remains low for a prolonged period, this can damage the kidneys and other organs," he says.

Stick to the recommended dosing as prescribed by your doctor. If you feel the dose is too low and isn’t having the desired effect, a healthcare professional can always gradually increase it to see how you tolerate it.

“If you take any of these blood pressure drugs as prescribed, there is almost zero risk that you will overdose," Lawrence says. "Blood pressure medications are never given on an as-needed basis. You are always instructed to take the same dose of whatever drug you're prescribed every single day. And if you do that, you will stay safe."