Metoprolol vs. atenolol: Differences, similarities, and which is better for you

Drug overview & main differences | Conditions treated | Efficacy | Insurance coverage and cost comparison | Side effects | Drug interactions | Warnings | FAQ

Metoprolol and atenolol are used in the treatment of various types of cardiac-related conditions including angina pectoris and hypertension, or high blood pressure. Angina pectoris refers to a condition where you experience chest pain or discomfort that is due to your heart not receiving enough oxygen-rich blood. This may be more likely to occur during periods of high stress or exertion. Hypertension refers to having high blood pressure where the blood flowing through your arteries is at a higher than normal pressure.

Metoprolol and atenolol are in the same drug class and treat similar conditions, but there are also some differences between these drugs, and we will discuss those here.

What are the main differences between metoprolol and atenolol?

Metoprolol is a prescription-only drug that is classified as a cardioselective beta-1-selective adrenergic agonist, otherwise called beta blockers. Beta 1 receptors are responsible for cardiac stimulation resulting in increased heart rate and stronger contractions of the heart muscle. Blocking these receptors, as metoprolol does, results in a slower heart rate and less forceful contractions. Metoprolol is cardioselective meaning it is more likely to only affect beta 1 receptors in the heart, and it is less likely to affect other types of beta receptors located throughout the body, such as in your airways.

Metoprolol is available in immediate-release tablets in 25 mg, 37.5 mg, 50 mg, 75 mg, and 100 mg tablets. The immediate-release is also known generically as metoprolol tartrate. The extended-release form of metoprolol, known as metoprolol succinate, is available in strengths of 25 mg, 50 mg, 100 mg, and 200mg. The extended-release capsules are available in the same strengths as the tablets. There is also a 1 mg/ ml injectable solution as well as an oral powder. The half-life of metoprolol tartrate is about three hours, and the half-life of metoprolol succinate is about seven hours. This means the extended-release formulation does not have to be dosed as often.

Atenolol is also a prescription drug that is classified as cardioselective beta-1-selective adrenergic agonist. It works in the same manner as metoprolol in the body. The half-life of atenolol is about six to seven hours, and therefore may last longer than some metoprolol doses. Atenolol is available in 25 mg, 50 mg, and 100 mg tablets.

Conditions treated by metoprolol and atenolol

Metoprolol and atenolol are both used in the treatment of angina pectoris and hypertension. They may be used in either chronic, stable angina or unstable angina. Chronic, stable angina occurs predictably when you exert yourself physically or are under a considerable amount of stress. Unstable angina is not predictable and may occur even at rest.

When used in the treatment of hypertension, metoprolol and atenolol may be used alone or in combination with other antihypertensive drugs. When these drugs are used in the treatment plan for an active, suspected, or confirmed myocardial infarction, or heart attack, they are part of a multi-drug regimen which may also include angiotensin-converting enzyme inhibitors (ACE inhibitors) and diuretics. In ischemic myocardial disease, beta blockers reduce the oxygen demand of the myocardial muscle and have antiarrhythmic properties.

Metoprolol and atenolol are also each used off-label for some indications. Off-label use refers to use for an indication that has not been approved by the Food and Drug Administration (FDA). They are commonly used to help prevent migraines and control tremors.

This may not be a complete list of possible uses for these drugs. Only your physician or cardiology specialist can decide if either of these drugs are appropriate for your condition.

Is metoprolol or atenolol more effective?

Metoprolol and atenolol have been studied and compared extensively for various indications and outcomes. A meta-analysis published in 2017 evaluated the comparative effectiveness of these two beta blockers along with propranolol and oxprenolol by looking at the results of multiple clinical trials. Metoprolol showed a more significant reduction in risk of cardiovascular mortality as compared to atenolol. Metoprolol also showed a decreased trend for all-cause mortality and coronary heart disease.  When evaluated for a decrease in risk of stroke, metoprolol proved to be superior to atenolol as well. There is data that suggests that both drugs are effective versus placebo and there is not a significant difference between atenolol and metoprolol in terms of their ability to control blood pressure (hypertension).

Metoprolol has been shown to decrease both systolic and diastolic blood pressure. Atenolol may affect systolic blood pressure more than diastolic, especially in times of exertion.

Based on this information, your doctor may choose to start with metoprolol first when selecting an agent for you. Only your physician can determine if beta blocker treatment is appropriate for you.

Coverage and cost comparison of metoprolol vs. atenolol

Metoprolol is a prescription medication that is covered by both commercial and Medicare insurance plans. If you pay cash for a metoprolol prescription, you could pay about $31 for a one month supply. SingleCare offers a coupon that would allow you to pay around $4 for metoprolol.

Atenolol is a prescription medication that is covered by both commercial and Medicare insurance plans. Without insurance, you could pay around $30 for a 30-day supply of 50 mg tablets. With a savings card from SingleCare, you could pay approximately $9 for this prescription.

Common side effects of metoprolol vs. atenolol

Cardioselective beta blockers such as metoprolol and atenolol slow the rate at which the heart beats as well the force with which it beats. This slowing of the heart rate can lead to bradycardia, or low heart rate. When the heart isn’t beating as forcefully, sometimes blood flow doesn’t reach the extremities with the pressure we would like, leading to extremities that may be cold to the touch.

Less forceful blood flow and decreased arterial pressure may also lead to side effects such as postural hypotension, a lightheaded and dizzy feeling upon standing after sitting or lying down. Headaches may also occur in patients taking metoprolol and atenolol.

This is not intended to be a complete list of side effects. Please consult your pharmacist or doctor for a complete list.

Source: Metoprolol (DailyMed)  Atenolol (DailyMed)

Drug interactions of metoprolol vs. atenolol

Digoxin and beta blockers such as metoprolol and atenolol each affect the forcefulness of contractions and heart rate. When given together, patients are at an increased risk of bradycardia and hypotension. Heart rate, blood pressure, and other signs of cardiac dysfunction should be monitored regularly if they must be given together.

Metoprolol and Atenolol combined with calcium channel blockers such as amlodipine may cause an additive reduction in cardiac contractility which could be dangerous. If the combination is necessary, it is important to get baseline function measurements and have a consistent follow-up.

Common antidepressants such as fluvoxamine, clomipramine, and selective serotonin reuptake inhibitors (SSRIs) inhibit an enzyme (CYP2D6) that is responsible for the metabolism of metoprolol. When given concomitantly with metoprolol, these drugs may lead to an increase in metoprolol blood levels. These could lead to increased effects by metoprolol on the cardiac system.

This is not intended to be an all-inclusive list of potential drug interactions. You should consult your healthcare professional for a complete list.

Warnings of metoprolol and atenolol

Beta blockers cause depression of cardiac contractility. In some patients with certain risk factors, this may precipitate heart failure. If this occurs, heart failure should be treated according to current guidelines.

Beta blockers should not be suddenly stopped, especially in patients with coronary artery disease. Heart attacks and ventricular arrhythmias have been reported in patients who abruptly discontinue beta blockers.

When possible, beta blocking agents should be avoided in patients with bronchospastic diseases, such as asthma. Concomitant use could exacerbate bronchial disease. If it is necessary to use beta blockers, cardioselective ones are preferred. The use of non-cardioselective beta blockers, such as carvedilol, is not recommended.

Atenolol dosing should be reduced in patients with renal disease or renal impairment as the excretion of the drug is slowed.

A randomized controlled clinical trial published by The Lancet suggests that patients who have surgery while on beta blockers (metoprolol specifically) are at an increased risk of a serious outcome such as heart attack or stroke. However, it is not advisable to stop the beta-blocker for surgery if a patient has been stabilized on it.

It is important to know it may be hard to notice signs of hypoglycemia in diabetic patients, such as tachycardia, because they will be masked by the effects of the beta blocker.

The dizziness and hypotension caused by metoprolol and atenolol can increase the risk and incidence of falls, which could be dangerous or lead to head injuries. Caution should be taken in older adults who are already at an increased risk of falls.

Only your doctor can decide if metoprolol or atenolol therapy are safe for you.

Frequently asked questions about metoprolol vs. atenolol

What is metoprolol?

Metoprolol is a prescription medication that is classified as a cardioselective beta blocker. It works to treat hypertension and angina by decreasing heart rate and the forcefulness of the heart’s contractions. It is available in immediate-release oral tablets, extended-release tablets and capsules, injectable solution, and oral powder.

What is atenolol?

Atenolol is a cardioselective beta blocker that is available by prescription only. It works to treat hypertension and angina by decreasing heart rate and the forcefulness of the heart’s contractions. It is available in immediate-release oral tablets.

Are metoprolol and atenolol the same?

Metoprolol and atenolol are each cardioselective beta blockers, and the pharmacology of how they work is similar, but they are not exactly the same. Metoprolol has two forms available, one short-acting and one long-acting, and may be dosed once or twice daily depending on the formulation. Metoprolol is also lipophilic, meaning it tends to dissolve in more fatty (lipid) environments. For this reason, taking Metoprolol with a meal is typically recommended. Atenolol is dosed once daily and is hydrophilic. Atenolol dissolves in more aqueous environments, and therefore only needs to be taken with a glass of water.

Is metoprolol or atenolol better?

Data suggests that these two drugs have similar outcomes in hypertensive patients, however long term cardiovascular disease outcomes, such as decreased morbidity, may be more favorable with metoprolol.

Can I use metoprolol or atenolol while pregnant?

Metoprolol is in Pregnancy Category C. There are no well-controlled studies to establish safety in pregnancy. Consult a physician regarding taking Metoprolol while pregnant or breastfeeding. Atenolol is in Pregnancy Category D. It is contraindicated and should not be taken during pregnancy. Consult a doctor regarding steps to take while planning pregnancy or breastfeeding.

Can I use metoprolol for atenolol with alcohol?

While there is no direct chemical interaction between alcohol and beta blockers like metoprolol and atenolol, alcohol consumption does cause your blood pressure to fall. The combined effect of the drugs and alcohol may put you at risk of fainting or falling and injuring yourself.