What to Know About Digoxin Levels

Medically Reviewed by James Beckerman, MD, FACC on September 04, 2023
4 min read

Digoxin is a medication used to help treat heart failure and heartbeat irregularities. Your digoxin levels tell you the amount of digoxin that is in your body at a certain time. Having too much or too little digoxin in your blood can be dangerous, so your doctor will test your digoxin levels to make sure you’re getting the right amount. Here’s what you need to know about how it can affect your health.

Digoxin is a medication that can help the heart muscle contract more strongly. This effect makes it useful for treating heart conditions that involve irregular heartbeats or heart failure. It’s most often used to treat congestive heart failure and atrial fibrillation.

This medication was originally discovered in the foxglove plant. Foxglove produces compounds that are poisonous to prevent animals from eating it. The most important compound, digitalis, affects the heart, and can be refined into the medication digoxin. Today, digoxin is made in the lab to guarantee consistency.

Digoxin has a narrow therapeutic range, which means that the dose of medication that’s dangerous is only a little higher than the dose that works. Without enough digoxin absorbed into your body, you may not feel the effects of the medication. However, too much digoxin can lead to symptoms of an overdose. The same effects that help stabilize your heartbeat at the right dose can go too far and cause additional health problems.

If you have a damaged or weakened heart, digoxin can help keep your heart beating regularly. This can help protect you against deadly heart attacks and heart failure. It can also keep you from experiencing chronic symptoms of heart problems.

However, the narrow therapeutic range of digoxin means that you have to be strict with your medication. Otherwise, you may suffer from an overdose. Digoxin overdose causes digoxin toxicity, which can cause problems like:

  • Tiredness
  • ‌Nausea
  • ‌Stomach pain
  • ‌Loss of appetite
  • ‌Vomiting
  • ‌Vision problems
  • ‌Irregular heart rate

‌If you don’t have enough digoxin in your blood, on the other hand, you may continue to have symptoms of your heart condition, including:

Before prescribing digoxin, your doctor will consider other treatments for your condition. If digoxin is the best option, then your health care team will begin the process of setting your digoxin dosage. They will consider your height, weight, gender, age, and any other health conditions when they set your initial dose.

They will have you take this dose of digoxin for several days. Then your doctor will have you complete a digoxin test to see whether you’re getting enough, too much, or too little of the medication. You may have your dose adjusted several times before you find the right amount for your body.

Your doctor will probably have you come in for testing regularly even after you have found a dose that works. This lets them keep an eye on your digoxin levels and make adjustments if your health changes.

Digoxin is quickly absorbed in your stomach and processed by your kidneys. To make sure you have enough but not too much digoxin in your blood, you will likely need to take it several times a day. Follow your doctor’s directions for how often to take digoxin so you don’t risk over- or underdosing on your medication.

Your digoxin level test can lead to one of three results: your levels are in the right range, they’re too low, or they’re too high. If your levels are right, then you’re taking the right dose. If your levels are too high or low, your doctor will adjust your dosage.

Low levels of digoxin are easiest to treat. Your doctor will make sure you have been taking your medication as prescribed. If you have, then they will prescribe you a slightly higher dose and then ask you to come back in several weeks for another digoxin level test to see if it’s working.

If your digoxin levels are too high, treatment may be more complicated. If your levels are just a little high, then your doctor will lower your prescribed dosage. They may also give you instructions for taking less digoxin until you can pick up your new prescription.

If your digoxin levels are very high, then you may need immediate treatment. Digoxin toxicity may require hospital treatment and medications that block the digoxin in your blood.

Digoxin is a useful medication, but you should be careful to always follow your doctor’s directions for it. If you notice any new symptoms or problems while you’re taking digoxin, always talk to your doctor about them as soon as possible.