Metoprolol is not an ACE inhibitor. It belongs to a completely different drug class called beta-blockers. The two types of medication both treat high blood pressure and heart failure, which is why they’re easy to confuse, but they work through different mechanisms in the body and have distinct side effect profiles.
What Metoprolol Actually Is
Metoprolol is a beta-blocker, meaning it works by blocking specific receptors on the heart. When these receptors are blocked, the heart beats more slowly and with less force, which lowers blood pressure and reduces the heart’s workload. Think of it as taking your foot off the gas pedal: the heart doesn’t pump as hard, so pressure in the blood vessels drops.
Metoprolol is FDA-approved for four conditions: high blood pressure, chest pain from reduced blood flow to the heart (angina), heart failure, and recovery after a heart attack. It’s also widely used off-label for fast or irregular heart rhythms, migraine prevention, essential tremor, and as a supporting treatment during thyroid storms.
The drug comes in two forms. Metoprolol tartrate is taken twice daily, while metoprolol succinate is an extended-release version taken once a day. Clinical research shows both produce similar effects on the heart and blood vessels over time, so the choice between them mostly comes down to convenience and the specific condition being treated.
How ACE Inhibitors Work Differently
ACE inhibitors lower blood pressure through an entirely different pathway. Instead of acting on the heart directly, they block an enzyme that produces a hormone called angiotensin II. That hormone normally tightens blood vessels. By preventing its production, ACE inhibitors allow blood vessels to relax and widen, reducing the resistance the heart has to pump against.
You can spot ACE inhibitors by their generic names, which almost always end in “-pril.” Common examples include lisinopril, enalapril, ramipril, and benazepril. Metoprolol’s name ending in “-olol” is the giveaway that it’s a beta-blocker, since most drugs in that class share the same suffix.
ACE inhibitors are approved for high blood pressure, heart failure, coronary artery disease, and recovery after a heart attack. They also have a significant role that beta-blockers don’t: protecting the kidneys. In people with chronic kidney disease or diabetes-related kidney damage, ACE inhibitors are recommended as a first-choice therapy to slow kidney decline, regardless of whether the person also has high blood pressure.
Why the Confusion Makes Sense
The overlap between these two drug classes is substantial. Both treat high blood pressure, both are used in heart failure, and both are prescribed after heart attacks. If you were told your medication is “for your heart” or “for blood pressure,” you might reasonably wonder which type you’re taking.
One practical difference: the 2025 guidelines from the American Heart Association and American College of Cardiology list ACE inhibitors as a first-line treatment for high blood pressure, alongside diuretics and calcium channel blockers. Beta-blockers like metoprolol are not recommended as a first choice for blood pressure alone. Research has shown they’re less effective than first-line options at preventing strokes and carry a less favorable side effect profile for that purpose. Beta-blockers are reserved for people who also have coronary heart disease or heart failure, where they provide distinct benefits.
Different Side Effects to Watch For
Because they target different systems, these drugs cause different side effects. Metoprolol commonly causes fatigue, dizziness, and slow heart rate. Some people notice cold hands and feet, since beta-blockers can reduce blood flow to the extremities. Exercise may feel harder because the heart can’t speed up as easily in response to physical activity.
ACE inhibitors are known for a persistent dry cough that affects a notable percentage of users. This cough isn’t dangerous, but it’s annoying enough that many people switch to a related class called ARBs (angiotensin receptor blockers), which work on the same hormonal pathway without triggering the cough. ACE inhibitors can also rarely cause swelling of the lips, tongue, or throat, which requires immediate medical attention. In head-to-head trials comparing lisinopril and metoprolol for mild to moderate high blood pressure, lisinopril was better tolerated overall, with significantly fewer people dropping out due to side effects.
Can You Take Both Together?
Yes, and many people do. Because beta-blockers and ACE inhibitors lower blood pressure through completely separate mechanisms, they complement each other. This combination is particularly common in heart failure, where guidelines recommend using both classes together. The ACE inhibitor reduces the strain on the heart by relaxing blood vessels, while the beta-blocker protects the heart from being overstimulated and helps prevent harmful structural changes to heart muscle over time.
If you’re taking metoprolol and your provider adds an ACE inhibitor (or vice versa), it’s not because one medication failed. The two drugs are tackling different pieces of the same problem, and the combination typically produces better outcomes than either drug alone for conditions like heart failure with reduced pumping ability.