Digitalis Medicines

Digitalis is used to treat congestive heart failure (CHF) and heart rhythm problems (atrial arrhythmias). Digitalis can increase blood flow throughout your body and reduce swelling in your hands and ankles.


Why do I need to take digitalis?

Digitalis is used to treat congestive heart failure (CHF) and heart rhythm problems (atrial arrhythmias). Digitalis can increase blood flow throughout your body and reduce swelling in your hands and ankles.

How does digitalis work?

  • Digitalis medicines strengthen the force of the heartbeat by increasing the amount of calcium in the heart’s cells. (Calcium stimulates the heartbeat.) When the medicine reaches the heart muscle, it binds to sodium and potassium receptors. These receptors control the amount of calcium in the heart muscle by stopping the calcium from leaving the cells. As calcium builds up in the cells, it causes a stronger heartbeat.
  • Digitalis medicines control irregular heart rhythms (called arrhythmias) by slowing the signals that start in the sinoatrial (SA) node. This, in turn, reduces the number of signals that travel through the atrioventricular (AV node). Fewer signals mean fewer arrhythmias.

How much do I take?

Your doctor will tell you when and how much of the medicine you should take, but here are some precautions:

  • The amount of medicine you need to take may vary.
  • Doses for children depend on the weight of the child.
  • If you are taking the liquid form of the medicine, the amount you should take should be measured only with the specially marked dropper you are given with the bottle of medicine.
  • If you miss a dose, take it as soon as you remember. If it is within 12 hours of your next dose, skip this missed dose and carry on with your regular schedule. Do not double your next dose.
  • Do not stop taking digitalis unless your doctor tells you to do so.

What if I am taking other medicines?

Other medicines that you may be taking can increase or decrease the effect of digitalis. These effects are called an interaction. Be sure to tell your doctor about every medicine and vitamin or herbal supplement that you are taking, so he or she can make you aware of any interactions.

The following are categories of medicines that can increase or decrease the effects of digitalis. Because there are so many kinds of medicines within each category, not every type of medicine is listed by name. Tell your doctor about every medicine that you are taking, even if it is not listed below.

  • Antiarrhythmic medicines
  • Certain antibiotics
  • Calcium channel blockers
  • Other heart medicines
  • Certain anti-anxiety medicines
  • Certain antifungal medicines
  • Ulcer or stomach medicines
  • Diarrhea medicines (containing diphenoxylate)
  • Antacids
  • Diuretics or water pills
  • Certain cancer medicines
  • Medicines for colitis
  • Certain cholesterol-lowering medicines

While on digitalis, you should also avoid caffeine and should not take diet pills, laxatives, or cough, cold, and sinus medicines.

What else should I tell my doctor?

Talk to your doctor about your medical history before you start taking digitalis. The risks of taking the medicine need to be weighed against its benefits. Here are some things to consider if you and your doctor are deciding whether you should take digitalis.

  • You have allergies to digitalis medicines or allergies to foods or dyes.
  • You are thinking of becoming pregnant, you are pregnant, or you are breast feeding your baby.
  • You are over 60 and are underweight or frail.
  • You have other medical problems, such as thyroid disease, liver disease, lung disease, or kidney disease.

What are the side effects?

Sometimes a medicine causes unwanted effects. These are called side effects. Not all of the side effects for digitalis are listed here. If you feel any other effects, you should check with your doctor.

Serious side effects:

  • An irregular heartbeat that causes dizziness, the feeling that your heart has skipped a beat (palpitations), shortness of breath, sweating, or fainting
  • Hallucinations, confusion, and mental changes like depression
  • Unusual tiredness or weakness
  • Trouble with your eyesight, such as blurry eyesight, double vision, or seeing yellow, green, or white halos around objects
  • A loss of appetite or an upset stomach

Common side effects:

  • Erectile dysfunction
  • Breast enlargement in men

Less common side effects:

  • A skin rash or hives
  • Headache
  • A numbness or tingling sensation over your body
  • Eye sensitivity to light
  • Diarrhea
  • Throwing up

Tell your doctor right away if you have any of these side effects. Do not stop taking your medicine unless your doctor tells you to. If you stop taking your medicine without checking with your doctor, it can make your condition worse.    

A consumer-based site by the American Society of Health-System Pharmacists that provides information about all types of medicines as well as safety tips for their proper use. The site’s search feature lets users search medicines by the brand or generic name.



The information in this Medicines for Cardiovascular Disease section has been taken from a number of sources. It is meant to give you information about certain medicines, but it does not cover all of the possible uses, warnings, side effects, or interactions with other medicines and vitamin or herbal supplements. This information should not be used as medical advice for individual problems. Please talk to your doctor and/or your pharmacist for prescription instructions.