Bumex vs. Lasix: Which Is Best for Hypertension Treatment?

Bumex (bumetanide) and Lasix (furosemide) are both in a class of drugs called loop diuretics. A drug class includes medications with similar actions and chemical structures, as well as those that have the same physiologic effects.

Loop diuretics are strong water pills that are prescribed for conditions such as congestive heart failure or other maladies that cause an excess build-up of fluid (edema) in the body. 

Bumex and Lasix (and other loop diuretics) work to improve symptoms such as:

• Edema (swelling) in the abdomen
• Edema in the upper and lower extremities
• Shortness of breath
• Ascites (fluid accumulation in the abdomen)
• Other symptoms caused by edema

What Are Bumex and Lasix?

Bumex and Lasix are loop diuretics, which work on the kidneys to increase the amount of fluid that the kidneys release (as urine). This occurs because loop diuretics interfere with the transport of salt and water across specific cells in an area of the kidneys called the “loop of Henle.”

These medications require careful monitoring by your healthcare provider. If too much fluid is lost, dehydration and electrolyte imbalance may result. Therefore, it’s vital to take loop diuretics exactly as prescribed and to promptly report any side effects.

The primary differences between these loop diuretics include:

• Bumex is much more potent: Bumex is 40 times more potent than Lasix. This translates to 1 mg of Bumex being equal to 40 mg of Lasix.
• Bumex has a lower risk of some adverse effects: One example is ototoxicity, which is an adverse reaction affecting the inner ear.
• Lasix is an older drug: It has been around longer than Bumex.
• Bumex is not intended for minors: It has not been approved for use in anyone under the age of 18.
• Lasix can be given to children: Based on a child's weight, Lasix may be given in specific situations. 
• Bumex can be given as an IM (intramuscular injection): IM administration of Lasix must be restricted to situations where it’s not feasible for a person to get an oral pill (due to gastrointestinal problems) nor is an intravenous administration possible (such as those with severe cellulitis in the extremities).
• Lasix is approved by the Food and Drug Administration (FDA) to treat hypertension: Bumex is not commonly used to treat high blood pressure, but it may be used off-label (a condition in which a drug or treatment has not been approved) for the treatment of hypertension.
• Lasix is available in 20 mg, 30 mg, and 80 mg tablets: Bumex is available in 0.5mg, 1mg, and 2mg tablets.
• Lasix begins working in approximately one hour: The peak action occurs within the first or second hour after oral administration. Lasix has a duration of approximately six to eight hours.
• Bumex begins working in approximately 30 to 60 minutes: It reaches its peak in one to two hours. Its diuretic action is slightly shorter than Lasix, lasting between four to six hours.

Some similarities between Bumex and Lasix are:

• Both are available as an oral (pill form taken by mouth) and an IV (intravenous) solution for situations where quick diuresis is necessary. 
• Both may be taken alone or in combination with other medicines to treat high blood pressure or other symptoms.

Uses of Bumex vs. Lasix

Hypertension

Loop diuretics, such as Bumex and Lasix are sometimes used to treat high blood pressure, but usually a different type of diuretic—called a thiazide diuretic—is used for the treatment of hypertension.

Blood pressure helps circulate blood throughout the body. When the blood pressure stays too high, even when a person is at rest, it’s called hypertension. If hypertension is left untreated, it can lead to serious health problems such as a stroke, heart disease, or kidney failure.

According to a 2016 study, loop diuretics such as Bumex and Lasix are not usually the first line of defense in treating hypertension, however, they have been shown to lower blood pressure.

It's important to note that although Bumex is sometimes used to treat high blood pressure, it is not FDA-approved for the treatment of hypertension. Talk to your healthcare provider about the use of Bumex to treat your high blood pressure.

More often, Bumex and Lasix are used to treat edema; both drugs can lower swelling in areas such as the legs, arms, and abdomen, caused by conditions such as heart failure and liver and kidney disease.

Congestive Heart Failure

Fluid overload from congestive heart failure is often treated by administering loop diuretics. Congestive heart failure (CHF) involves inadequate pumping of the blood throughout the body, which results in fluid accumulation. 

This ends up causing fluid to accumulate in areas such as the lungs and lower extremities (the legs and ankles). This fluid accumulation in the extremities is called edema. Fluid accumulation in the lungs is called pulmonary edema.  

Kidney and Liver Conditions

Other conditions that cause fluid to accumulate in the body include certain kidney and liver disorders. When the kidneys are not functioning as they should, they cannot work to effectively remove fluid from the body (via urine production). This results in an excess of fluid in the blood, which builds up in the body tissues in the form of edema.

Liver cirrhosis causes fluid to build up in the abdomen (this is called ascites). Liver cirrhosis is the most common cause of ascites, but kidney failure and congestive heart failure can also cause ascites. When the liver is involved, ascites occurs from two causes, including:

• An elevation of blood pressure in the veins that run through the liver (called portal hypertension)
• A decrease in liver function due to scarring.

Lasix (along with a potassium-sparing diuretic, called spironolactone) is the type of diuretic most commonly given to treat ascites in those with cirrhosis.

Uses of Bumex

The primary use for Bumex is the treatment of fluid accumulation (edema) caused by congestive heart failure.

Other conditions that cause edema to accumulate in the body, in which Bumex is often used for diuresis (an increase in urine production), include:

• Kidney disease (such as in nephrotic syndrome, a type of kidney condition characterized by edema and the loss of protein from the plasma [the part of the blood that carries water, salts and enzymes] into the urine)
• Liver disease  (such as cirrhosis which is scarring of the liver caused by various liver disorders)
• Edematous conditions due to cardiac (heart) failure

Bumex can be given alone, or in combination with other diuretics to treat edema, such as amiloride. 

The Food and Drug Administration (FDA) has approved the use of Bumex for those who are allergic to Lasix. According to the FDA, “Successful treatment with Bumex following instances of allergic reactions to furosemide suggests a lack of cross-sensitivity.”

Uses of Lasix

Lasix is indicated for the treatment of pediatric patients and adults with edema associated with:

• Congestive heart failure
• Cirrhosis of the liver
• Nephrotic syndrome (and other types of kidney disease involving fluid retention)
• Lasix may be given as an antihypertensive medication to lower blood pressure.
• Lasix is indicated when a person is in need of a potent diuretic.

Side Effects

Side Effects of Bumex

Common side effects of Bumex may include:

• Frequent urination (which is the most common side effect)
• Dizziness or lightheadedness
• Nausea
• Diarrhea

If you have any common side effects from Bumex that don’t subside, or if the side effects are severe, contact your healthcare provider.

Severe side effects of Bumex may include:

• Ringing in the ears (a sign of ototoxicity which could lead to hearing damage if not treated right promptly)
• Loss of hearing
• Bleeding
• Symptoms of an allergic reaction (including a severe skin rash/hives, swelling of the tongue or throat trouble swallowing and/or trouble breathing)

If you have symptoms of an allergic reaction while taking Bumex, seek emergency medical attention right away.

Side Effects of Lasix

Side effects of Lasix may include:

• Frequent urination
• Headache
• Blurred vision
• Constipation or diarrhea

If any of these common side effects are severe or they do not go away, it's important to contact your healthcare provider.

Serious side effects of Lasix may include:

• Fever
• Ringing in the ears
• Hearing loss
• An allergic reaction (such as a severe rash or hives, itching, trouble breathing, or swallowing)

If you have any of these serious side effects, it’s important to seek immediate emergency medical treatment.

Warnings

Black Box Warning

Both Bumex and Lasix have what is commonly called a “black box warning." This is the most serious warning issued by the FDA, which refers to a drug that can potentially cause dangerous adverse reactions.

Lasix and Bumex both have the potential to result in dangerously low levels of electrolytes (such as potassium and sodium) and water in the body; low body fluid can lead to dehydration. Very close medical observation is required while taking loop diuretics such as Bumex and Lasix.

Bumex Warnings

Precautions and Contraindications    

A contraindication is a situation when a certain drug, treatment or procedure should not be given or performed because it could potentially cause harm.

Contraindications for Bumex include:

• Children: Anyone under the age of 18.
• Pregnancy: Use with extreme caution during pregnancy; Bumex should only be given if the benefits of the drug are stronger than the unknown fetal risks (safety to the fetus has not been well established).
• Breastfeeding mothers: The safety of the use of Bumex for breastfeeding infants has not been well established by clinical research studies.
• Those with low urine output (oliguria): This is linked with kidney disease.
• An increase in blood urea nitrogen (BUN): This may indicate malfunctioning kidneys.
• Those who are in a hepatic coma: This is a severe liver disease stage.
• Those with severe imbalances of electrolytes: For example, low sodium levels.
• Those with an allergy to Bumex

Bumex Drug Interactions

Drugs that should not be taken with Bumex include:

• Any other drug that could cause ototoxicity (such as aminoglycoside antibiotics)
• Drugs that have the potential to be toxic to the kidneys

Specific drugs that are contraindicated when taking Bumex include:

• Lithium: Bumex can increase the risk of lithium toxicity.
• Probenecid: This increases urine output.
• Indomethacin: This interferes with the therapeutic action of Bumex.

Drugs that should be used with caution with Bumex include high blood pressure medications (called antihypertensive medications), which may result in blood pressure that is too low. When antihypertensive medications are given with Bumex, this results in a need to lower the dosages of these drugs.

Lasix Warnings

Precautions and Contraindications    

Contraindications for Lasix include those with:

• Allergies to sulfonamides (cross-sensitivity with Lasix has been seen, but it is a rare condition)
• Electrolyte imbalance (such as low sodium levels, low potassium levels, and more)
• Hepatic coma
• Cirrhosis of the liver (use with caution in those with cirrhosis as sudden changes in fluid and electrolyte balance may lead to hepatic coma)

In those with severe kidney impairment, cases of tinnitus (ringing in the ears) and severe irreversible or reversible hearing impairment have been reported among those taking Lasix with aminoglycoside antibiotics (such as gentamycin) or other ototoxic drugs.

A Word From Verywell

The most important thing to keep in mind when taking any type of loop diuretic, including Lasix and Bumex, is that very close supervision by your healthcare provider is imperative for the duration that you are taking the drug. Always follow your healthcare provider’s instructions closely, and promptly report any side effects or adverse reactions you experience while taking diuretics.