If you’ve got congestive heart failure, hypertension (high blood pressure) or kidney disease, your doctor may be concerned about a big problem: edema, a condition that happens when there’s too much fluid and salt in your body. Luckily, there’s a good solution: a medication called bumetanide, which you might know by the brand name Bumex.

This drug is a diuretic, or water pill, and it helps your body balance your fluid levels. “When the excess water is gone, your heart works better and your blood pressure improves, which lowers your risk of a stroke or heart attack,” says Katherine Di Palo, PharmD, a pharmacist and clinical program manager at Montefiore Health Systems in New York. “Those are really complicated disease that can cut your life short.”

But, as with any drug, bumetanide may come with some unwanted side effects. So to get the most out of it, it helps to know a lot about it. We spoke with Di Palo to find out what you need to know about this safe, effective drug.

How can bumetanide help me?

Di Palo: If you have hypertension, taking bumetanide prevents your body from reabsorbing salt and retaining water, lowering your high blood pressure. And if you have heart failure, less water means less fluid buildup or swelling. Bumetanide can even address the swelling that may come from kidney or liver disease.

How does bumetanide work?

Di Palo: Bumetanide is a very powerful “loop” diuretic — that’s a class of medicine that acts on a particular area of your kidneys called the loop of Henle. It comes as a pill, and it causes your body to make more urine. So when you pee, you eliminate that extra water and reduce the swelling. When you take bumetanide, you may find yourself going to the bathroom more often. That can be inconvenient sometimes, but it tells you that the medicine is doing its job.

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How soon will I see results after taking bumetanide? 

Di Palo: Bumetanide works really fast. You’ll probably need to pee about half an hour after you take your pill. And you may start seeing results after you’ve been on it for about a week. You may notice less swelling in your legs or feet, and if you had been feeling breathless, that may be starting to get better too.

Are there any side effects with bumetanide?

Di Palo: There are lots of side effects, from small things that aren’t usually serious to big things that are very rare and you should be concerned about.

Muscle cramps. This is the most common side effect. It happens because when you pass more urine, you lose electrolytes — those are chemicals such as salt, magnesium and potassium that help control your body’s fluid levels and keep your cells working the way they’re supposed to. Potassium sends signals between your brain and your muscles that start — and stop — contractions. So if your potassium levels are too low, those muscle contractions may last a long time, making you experience painful cramps. Let your health care team know; they may want you to take a potassium supplement or add more potassium to your diet with foods such as bananas or spinach.

Abnormal heart rhythms. Too-low potassium or magnesium can also cause an abnormal heart rhythm, which could lead to a serious cardiac event. If you notice chest pains or a rapid heartbeat, call your care team right away.

Dizziness: Bumetanide lowers your blood pressure, and if it goes a little too low, you may have a headache or feel a bit dizzy. If you feel lightheaded, try to get up slowly after you’ve been sitting or lying down, and be extra-careful about avoiding falls. Don’t drive until you know how the medication affects you.

Tummy troubles. Some people experience nausea or vomiting when they first start taking bumetanide. If that happens, try taking your pill with food.

Allergic reaction: Bumetanide contains a very small amount of sulfa, so if you’ve ever experienced an allergic reaction to a sulfa antibiotic (like Septra or Bactrim) let your doctor know. You might get a minor rash, but it’s extremely unlikely you’d experience anything more serious; the amount of sulfa in this medicine is quite small. Still, if you start having difficulty breathing, an extreme rash or swelling, call your doctor or go to the emergency room right away.

How should I take bumetanide?

Di Palo: Bumetanide is usually a once-a-day medication. Your provider will probably start you at a low dose and may increase the amount until you get to the desired effect. One important tip: The effect you’ll notice right away is that you’ll be going to the bathroom more, which can be inconvenient if you’re going out to work or running errands. So add your pill to your early morning regimen. That way, you can get your bathroom trips out of the way before you leave the house — and you won’t be kept up at night.

Do I need to keep in touch with my doctor?

Di Palo: Yes! A dialogue with your care team is really important. If you’re taking bumetanide for heart failure, they’ll want to hear if you’ve noticed any improvements in swelling or if your breathing has improved. Your team will monitor your blood pressure and do some blood work to check your electrolyte levels and look to see if any swelling has gone down.

Depending on the results, they may need to add some supplements — extra potassium — or ask you to make some changes to your diet. They may even want to adjust your dose, possibly adding a second pill later in the day. That is why it’s so important to keep your follow-up appointment, usually a week or two after you start on the medication. It’s a way for your provider to get you on exactly the right dose to help you, while minimizing your risk of side effects.

Taking your high blood pressure medication is step one. Learn what else you can do to lower your risk of a stroke today.