Pindolol Drug Interactions: What You Need to Know

If you're taking Pindolol — or about to start — it's important to understand how it interacts with other medications, supplements, and even some foods. Drug interactions can make Pindolol less effective, increase side effects, or create dangerous health risks.

This guide covers the major and moderate interactions you should know about and what to tell your doctor before starting treatment.

How Drug Interactions Work

Drug interactions happen when one substance changes the way another works in your body. With Pindolol, interactions can occur in several ways:

• Additive effects — Another medication does the same thing as Pindolol (like slowing your heart), and the combined effect becomes too strong.
• Opposing effects — Another medication counteracts what Pindolol is trying to do, making it less effective.
• Masking effects — Pindolol hides symptoms of a problem caused by another medication (like low blood sugar from insulin).
• Changed metabolism — Another drug changes how fast your body breaks down Pindolol, raising or lowering its levels in your blood.

Major Drug Interactions (Avoid or Use Extreme Caution)

These interactions are serious and may require avoiding the combination entirely or very close medical monitoring:

Thioridazine (Mellaril) — Contraindicated

Taking Pindolol with Thioridazine is contraindicated (should never be done). The combination increases the risk of QTc prolongation — a dangerous change in your heart's electrical rhythm that can lead to torsades de pointes, a potentially fatal arrhythmia.

Verapamil (Calan, Verelan) and Diltiazem (Cardizem, Tiazac)

These calcium channel blockers, when combined with Pindolol, can cause severe bradycardia (dangerously slow heart rate) and heart block. Both drug classes slow the heart, and together the effect can be life-threatening. If you need both a beta blocker and a calcium channel blocker, your doctor will choose the combination carefully and monitor you closely.

Clonidine (Catapres)

If you take Clonidine and Pindolol together, stopping Clonidine suddenly can cause rebound hypertension — a dangerous spike in blood pressure. If both drugs need to be discontinued, your doctor will stop Pindolol first, then taper Clonidine gradually.

MAO Inhibitors

Monoamine oxidase inhibitors (such as Phenelzine, Tranylcypromine, or Selegiline) can interact unpredictably with beta blockers. Use this combination only under close medical supervision.

Digitalis Glycosides (Digoxin)

Both Digoxin and Pindolol slow the heart rate. Together, they can cause excessive bradycardia. Your doctor will monitor your heart rate and may adjust doses of either medication.

Other Beta Blockers

Taking Pindolol with another beta blocker (like Propranolol, Metoprolol, or timolol eye drops) can cause additive effects, including dangerously low heart rate and blood pressure. Even beta blocker eye drops for glaucoma can contribute to this interaction.

Moderate Drug Interactions

These interactions are important to know about but can often be managed with dose adjustments or monitoring:

NSAIDs (Ibuprofen, Naproxen, Aspirin)

Nonsteroidal anti-inflammatory drugs like Ibuprofen (Advil, Motrin), Naproxen (Aleve), and high-dose Aspirin can reduce Pindolol's blood pressure-lowering effect. If you need a pain reliever, Acetaminophen (Tylenol) is generally a safer choice while on a beta blocker.

Insulin and Oral Diabetes Medications

Pindolol can mask the symptoms of low blood sugar (hypoglycemia), particularly the rapid heartbeat and trembling that usually warn you your blood sugar is dropping. If you have diabetes, monitor your blood glucose more frequently and be aware that you may not feel the usual warning signs.

Catecholamine-Depleting Drugs (Reserpine)

Reserpine depletes the body's stores of adrenaline-like chemicals. Combined with Pindolol's beta-blocking effects, this can cause excessive hypotension (very low blood pressure) and bradycardia.

Aluminum Hydroxide Antacids

Antacids containing aluminum hydroxide can reduce Pindolol absorption. If you take antacids, try to take them at least 2 hours before or after Pindolol.

General Anesthetics

If you're having surgery, tell your anesthesiologist that you take Pindolol. General anesthetics can add to Pindolol's heart-slowing effects, causing additive myocardial depression. Your surgical team needs to know so they can adjust their approach.

Supplements and Over-the-Counter Products to Watch

• Decongestants (Pseudoephedrine, Phenylephrine) — Found in many cold and sinus medications. These stimulate the heart and blood vessels, counteracting Pindolol and potentially raising blood pressure.
• Epinephrine (EpiPen) — Pindolol can reduce the effectiveness of Epinephrine in treating severe allergic reactions (anaphylaxis). If you have severe allergies and carry an EpiPen, discuss this with your doctor.
• Herbal supplements — St. John's Wort, Ginseng, and Licorice root can affect blood pressure and heart rate. Tell your doctor about any supplements you take.

Food and Drink Interactions

Pindolol has no significant food interactions, which is good news. You can take it with or without food. However, keep these general tips in mind:

• Alcohol — Can add to Pindolol's blood pressure-lowering effect and increase dizziness. Drink in moderation, if at all.
• Caffeine — High caffeine intake can counteract some of Pindolol's effects by stimulating the heart. Moderate your intake if your blood pressure isn't well-controlled.

What to Tell Your Doctor

Before starting Pindolol, make sure your doctor knows about:

• All prescription medications you take, including eye drops
• All over-the-counter medications, especially pain relievers, cold medicines, and antacids
• All supplements and herbal products
• Whether you have diabetes — blood sugar monitoring may need adjustment
• Upcoming surgeries — your surgical team needs to know
• Allergies — especially if you carry an EpiPen

Bring a written list to your appointment. It's easy to forget something in the moment, and drug interactions with Pindolol can be serious.

Final Thoughts

Pindolol is a safe and effective medication when used properly, but it has important drug interactions that require attention. The most critical one to remember is the contraindication with Thioridazine — these two drugs should never be taken together. Other major interactions with Verapamil, Diltiazem, and Clonidine require careful management.

For more about Pindolol, explore our guides on side effects, uses and dosage, and how Pindolol works. If you need help finding Pindolol at a pharmacy, Medfinder can help you locate it quickly.