7 Labetalol Interactions to Be Aware of

Labetalol is a beta blocker that’s prescribed for high blood pressure and other heart-related conditions. It’s a first-choice medication for extremely high blood pressure and high blood pressure during pregnancy. But it’s also good to be aware that labetalol can interact with other medications you’re taking.

Here are seven labetalol interactions you should know about. Keep in mind that this isn’t a complete list of all possible interactions. So it’s best to review your medication list with your prescriber before you start taking labetalol.

1. Digoxin

Digoxin (Lanoxin) is a medication that’s used to treat an irregular heartbeat (arrhythmia). If you take labetalol with digoxin, there’s a risk that your heart rate will slow down too much (bradycardia).

Promotional Disclosureinfo_outlined

SPECIAL OFFER

Save over 40% on Qsymia with GoodRx

Discover the once daily Qsymia for weight management. Qsymia is for adults and children 12-17 in combination with a healthy diet and regular exercise.

Save now

In cases where you need to take both medications, your prescriber will likely keep a close eye on your heart rate to make sure it stays in a safe range. Be sure to let them know if you notice symptoms of bradycardia, such as:

• Unexplained fatigue 

• Fainting

• Chest pain

• Poor exercise tolerance

• Shortness of breath

• Dizziness or lightheadedness

Keep in mind that labetalol itself may cause some of these symptoms when you first start taking it. But it’s still a good idea to let your prescriber know if they appear. They can help pinpoint the cause and advise you on the best course of action.

Promotion disclosure

Labetalol

Avg retail price

$23.08(Save 40.42%)

GoodRx discount

$13.75

See all discounts

How it works

Use GoodRx to find medications, pharmacies, and discounts.

GoodRx discounts can help you pay less for your prescription.

Bring your free coupon or savings card to the pharmacy.

2. Other blood pressure medications

There are several different types of medications used to manage high blood pressure. Taking labetalol with other blood pressure medications may cause your blood pressure to drop too low (hypotension).

Diuretics are a common type of blood pressure medication that’s often combined with labetalol. Your prescriber will likely keep an eye on your blood pressure or have you test it at home to make sure it doesn’t drop too low if you’re taking these medications together.

Other blood pressure medications, such as calcium channel blockers, are more risky if they’re taken along with labetalol. That’s because certain calcium channel blockers can slow your heart rate as well as lower your blood pressure. So there’s a higher risk your blood pressure or heart rate will drop too low with both medications. Common calcium channel blockers with these effects include verapamil (Verelan, Verelan PM) and diltiazem (Cardizem, Cartia XT).

Symptoms of low blood pressure include:

• Dizziness

• Feeling faint or light-headed

• Blurry vision

• Feeling weak

Let your prescriber know if you start having symptoms of low blood pressure while taking labetalol. They can help determine if an interaction is to blame.

3. Nitroglycerin

Nitroglycerin (Nitrostat, NitroMist) is a medication that prevents or treats chest pain (angina). It works by relaxing your blood vessels. Usually, your body responds to this by increasing your heart rate to keep your blood pressure from dropping. But labetalol prevents this from happening because it slows your heart rate down. As a result, combining labetalol and nitroglycerin could cause your blood pressure to drop too low.

If you need to take these medications together, be mindful that you may suddenly feel dizzy or faint. It’s best to sit down or use support when walking until these symptoms pass. Let your healthcare team know if your blood pressure drops below 90/60 mmHg or if you pass out. You may need a medication adjustment.

4. Stimulants such as Adderall and caffeine

Stimulants are medications used to treat health conditions such as attention-deficit hyperactivity disorder (ADHD) or obesity. Examples include mixed amphetamine salts (Adderall) and phentermine (Adipex-P, Lomaira). Caffeine is a natural stimulant found in food and drinks as well as several over-the-counter (OTC) medications for migraine or to help you stay awake.

Stimulants can raise your blood pressure and increase your heart rate. This is the opposite of labetalol’s effects. So labetalol may not be as effective if you combine it with stimulant medications. One or 2 cups of coffee is likely OK with labetalol, but it’s best to keep your caffeine intake to a minimum.

Your prescriber may prefer a non-stimulant medication option for your health condition if you’re taking labetalol. If you need to take a stimulant medication with labetalol, they may have you keep a closer eye on your blood pressure and let them know if it’s higher than it should be. 

5. Certain inhalers for asthma or COPD

Labetalol is a non-selective beta blocker. This means it blocks beta receptors (binding sites) in the lungs and other parts of the body, as well as in the heart.

Certain inhaled medications that help manage asthma and chronic obstructive pulmonary disease (COPD) bind to beta receptors in the lungs to help widen your airways and help you breathe. Since labetalol blocks these receptors, it can prevent these inhalers from working as well. The inhalers labetalol interacts with include:

• Rescue inhalers, known as beta agonists, such as albuterol (ProAir, Ventolin HFA) and levalbuterol (Xopenex HFA)

• Maintenance inhalers, known as long-acting beta agonists (LABAs), such as salmeterol (Serevent) and formoterol (Perforomist)

• Combination inhalers that contain a LABA or beta agonist, such as Dulera (mometasone / formoterol) or Airsupra (albuterol / budesonide).

Let your prescriber know if you’re using inhalers to treat a lung condition. They may decide that a selective beta blocker, such as atenolol (Tenormin), is a safer treatment option for you.

If you notice worsening asthma or COPD symptoms while taking labetalol, be sure to let your healthcare team know. And seek emergency care if you’re struggling to breathe and your rescue inhaler isn’t working.

6. Cimetidine

Cimetidine (Tagamet HB) is an OTC medication for heartburn. It’s also available with a prescription.

Cimetidine can raise labetalol levels in the body if they’re combined. This can increase the risk of labetalol side effects, such as low blood pressure and a slow heart rate.

Talk to your pharmacist or prescriber if you’re looking for heartburn medication. They can recommend a safer option that won’t interact with labetalol and make sure it’s safe to take with your other medications, too.

7. Tricyclic antidepressants

Tricyclic antidepressants (TCAs) treat depression, anxiety, and other health conditions. Examples include amitriptyline and nortriptyline (Pamelor). These medications work by raising the levels of two hormones (serotonin and norepinephrine) in the brain.

One survey noted a higher risk of tremors in people taking a TCA and labetalol together versus labetalol alone. It’s not clear how common this interaction is, or why it happens. But if you notice new or worsening shaking of some part of your body, such as your hands, head, or voice, let your prescriber know. They may need to adjust your medication to manage it.

Why trust our experts?

Written by:

Emilie White, PharmD

Emilie White is a clinical pharmacist with over a decade of hospital pharmacy experience. Her professional areas of interest include critical care as well as infectious and autoimmune diseases.

Edited by:

Stacia Woodcock, PharmD

Stacia Woodcock, PharmD, is a pharmacy editor for GoodRx. She earned her Doctor of Pharmacy degree from the University of Kentucky and is licensed in New York and Massachusetts.

Reviewed by:

Austin Ulrich, PharmD, BCACP

Austin Ulrich, PharmD, BCACP, is a board-certified ambulatory care clinical pharmacist. In his early career, he provided direct patient care in a variety of settings, including hospital and community pharmacies, and in a primary care clinic as a clinical pharmacist.

Our editorial standards

Meet our experts