Dear NP

Dear NP,

“I was recently started on metoprolol for high blood pressure. I have never taken any prescription medications for blood pressure problems. Before starting the medication, I was able to walk at a fast pace for about 30 minutes. Now, I cannot tolerate any exercise, and I get tired very easily. Could it be due to the new medication?”

Dear Reader,

First, I’m happy to hear that you are addressing your high blood pressure. High blood pressure is known as the “silent killer” because it often does not show any symptoms until serious damage to the body has occurred.

High blood pressure is a risk factor for heart disease and stroke, which are the leading causes of death in the United States. Nearly half the adults in the U.S. have high blood pressure, and of those, only one in four have their blood pressure adequately controlled.

There are several classes of medications that are given to lower blood pressure. The major classes of medicines used in high blood pressure include angiotensin converting enzyme (ACE) inhibitors, beta-blockers, calcium channel blockers and angiotensin II receptor blockers (ARBs).

Each of these medications works a little differently to help control blood pressure. Blood pressure medications do have potential side effects, and the symptoms you are describing could be related to your medication. Let’s discuss how each class of medicine works and why it could cause a side effect.

ACE inhibitors work by helping the body produce less of a chemical known as angiotensin. Angiotensin is what normally makes our vessels narrow or tighten. By inhibiting angiotensin, ACE inhibitors relax blood vessels, which results in lower blood pressure.

Beta-blockers work through lowering heart rate and improving the pumping efficiency of the heart.

Calcium channel blockers also lower heart rate and relax and open up blood vessels.

ARBs block receptors that angiotensin would usually affect. Through blocking these receptors, blood vessels do not narrow or constrict and remain more relaxed.

Based on the symptoms of fatigue and reduced exercise tolerance, I would suspect that you may be taking either a beta-blocker or a calcium channel blocker to treat your high blood pressure. Because these medications lower heart rate and the heart’s pumping action, it is not uncommon to experience fatigue when starting medication. Another possibility is that your new lowered blood pressure is causing you to feel fatigued.

While the side effects you are experiencing are unpleasant, it is essential not to stop the medication without talking to your healthcare provider. In some cases, these effects will resolve once your body adjusts to the new medication. In other instances, your healthcare provider may decide it’s best to change to a different medication.

Track and keep a log of your daily blood pressure and heart rate to discuss with your healthcare provider. This information will help them decide the best way to address your high blood pressure while keeping you feeling well.

Dr. Wesley Davis is an Emergency Nurse Practitioner at Crook County Medical Services District and Coordinator of the Family and Emergency Nurse Practitioner program at the University of South Alabama. He encourages readers to send their questions to [email protected]