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Key takeaways
Switching from torsemide to furosemide can be done safely with advice and monitoring from a healthcare professional.
To minimize side effects from the switch, patients should closely monitor their hydration and electrolyte levels through regularly scheduled blood tests.
Other treatment options for high blood pressure include beta blockers (beta receptor antagonists), calcium-channel blockers, angiotensin-converting enzyme (ACE) inhibitors, angiotensin receptor blockers (ARBs), and other medications. For edema, bumetanide and compression socks may be helpful.
Torsemide and furosemide can be purchased at a lower cost using one of SingleCare’s prescription discount cards.
Torsemide, also known as torasemide, is a diuretic. It treats hypertension (aka high blood pressure) and edema (aka fluid retention) caused by congestive heart failure or chronic heart failure, liver disease, and kidney disease. It comes in tablet form.
Furosemide is another diuretic used to treat fluid retention and high blood pressure. Oral furosemide is an option, or it can be taken by intramuscular injection or intravenous injection.
People with high blood pressure are in good company: Statistically, hypertension affects more than 122 million people, according to the American Heart Association. High blood pressure is defined as the systolic number being higher than 130 mmHg or the diastolic number being 80 mmHg or more.
About 19% of people have edema, which often causes discomfort, weakness, and a limited range of motion.
Both of these medical conditions often impact a person’s quality of life. They can also contribute to more serious conditions, such as heart disease and other diseases.
Further, the management of heart failure, in particular, is important because decompensated heart failure can contribute to kidney and liver dysfunction, as well as the worsening of pulmonary hypertension. Heart failure patients are at increased risk for heart conditions of irregular heartbeat, valvular heart disease, and sudden cardiac arrest.
Switching from torsemide to furosemide
Treatment is important, but patients may not be satisfied with the medication they take due to ineffectiveness or a change in insurance coverage. For example, some people who take torsemide may want to switch to furosemide because of its benefits.
First, note that diuretic therapy is a standard treatment for edema and is often an add-on medication to help control elevated blood pressure. Out of all the loop diuretics, these two are the most commonly used to treat acute decompensated heart failure, with the two hallmark symptoms of congestion and volume overload.
Further, thiazide and similar diuretics aren’t as effective as loop diuretics since they can only achieve a maximum natriuresis of about 3-5% of the filtered sodium load (aka they can’t excrete as much sodium).
In other words, torsemide and furosemide have benefits compared to similar medications. But can a person switch from torsemide to furosemide?
Clinicians say yes.
“It is possible and sometimes advisable to switch from torsemide to furosemide, depending on clinical judgment,” says Dr. Raj Dasgupta, MD, the chief medical adviser for Fortune Recommends who’s quadruple board-certified in internal medicine, critical care medicine, pulmonary medicine, and sleep medicine.
Dr. Sam Setareh, MD, a cardiologist at Cedars-Sinai Medical Center and director of clinical cardiology at Beverly Hills Cardiovascular, agrees. He says both torsemide and furosemide are loop diuretics, but they do have differences. Hence, there is a question about which is better or if switching medication is worth it.
What are the benefits of switching from torsemide to furosemide?
People may want to switch from torsemide to furosemide for a few reasons:
Furosemide is easier to get and take
Cost is one factor to consider. “Furosemide is generally less expensive and more widely available than torsemide,” Dr. Dasgupta says. (Those specifics are in the chart below.)
Furosemide also comes in more forms (oral, intramuscular, and intravenous) than torsemide, which is only available orally. So, if someone doesn’t want to take torsemide by mouth—the only way it can be taken—they may want to change to furosemide.
Furosemide has greater kidney bioavailability, and one dose works longer
“Bioavailability” refers to a medication’s ability to be absorbed and used by the body. Furosemide has greater kidney bioavailability. It has a longer duration of natriuresis (the removal of excess sodium through urination).
Furosemide has a different pharmacokinetic profile
“Another reason could be specific clinical scenarios where furosemide’s pharmacokinetic profile may be preferred over torsemide,” Dr. Dasgupta says. “This may happen in cases of renal impairment where furosemide’s higher bioavailability could offer better diuretic coverage.”
However, some people may want to switch from furosemide to torsemide or simply stay on torsemide.
To explain the latter, let’s look at the TRANSFORM-HF randomized clinical trial, which assessed the effects of torsemide and furosemide. While furosemide is the most commonly used loop diuretic for heart failure, torsemide may benefit myocardial fibrosis, aldosterone production, sympathetic activation, ventricular remodeling, and natriuretic peptides.
Other clinical outcomes from this study were as follows: Patients in the torsemide group did not show a significant difference in all-cause mortality over 12 months compared to the furosemide group. The patient-reported effects were similar regardless of cardiac ejection fraction, previous loop diuretic use, and baseline health status.
So, before making the switch, consider all the differences between the two medications:
| Torsemide vs. furosemide comparison chart | ||
|---|---|---|
| Torsemide | Furosemide | |
| Form | Tablet | Tablet, oral solution, intramuscular injection, or intravenous injection |
| Dosage | 5 to 20 mg mg once daily | 20 to 80 mg, with the second dose given 6 to 8 hours later |
| Bioavailability | Greater bioavailability, generally speaking | Greater kidney bioavailability |
| Cost | $6 | $3 |
| Population treated | Adults | Adults and some children |
How to switch from torsemide to furosemide
Some special directions must be heeded with a torsemide-to-furosemide conversion.
For one, equivalent doses are not the same milligram. “Dosage adjustments are necessary since torsemide is more potent on a per milligram basis compared to furosemide,” Dr. Dasgupta says. “Typically, the conversation ratio is approximately 1:2.” In other words, a patient taking 20 mg of torsemide may need 40 mg of furosemide.
“It’s generally not necessary to taper off torsemide before starting furosemide,” he adds, “but this should be guided by a healthcare provider’s advice based on your health needs.”
Dr. Setareh agrees the switch should be monitored by a health professional, “especially in patients with kidney issues or heart failure to ensure effective fluid control and avoid dehydration.”
Thankfully, both furosemide and torsemide have similar drug interactions, according to Dr. Dasgupta, since they’re both loop diuretics. This means—to an extent—that patients shouldn’t have to stop taking any drugs they were able to take while on torsemide.
However, the two drugs are still different. “Furosemide might interact slightly differently due to its variable absorption and pharmacodynamics,” Dr. Dasgupta adds. “One specific concern might be its interaction with drugs like lithium, as furosemide can increase lithium concentrations in the blood, potentially leading to toxicity.”
Dr. Setareh adds that furosemide may have slightly more potential for interactions—especially with medications that affect potassium levels. “For instance, furosemide may more significantly affect electrolyte balance, so interactions with digoxin (which can be affected by potassium levels) may need closer monitoring.”
Side effects from stopping torsemide and starting furosemide
Making this switch is generally pretty simple, though. “Most patients tolerate the switch well if the dosage adjustments are correct,” Dr. Setareh says.
However, since furosemide has a shorter half-life, he says, patients may notice increased urinary frequency or changes in fluid control patterns.
Additionally, Dr. Dasgupta says that people who stop torsemide and start furosemide may have side effects due to the potency and duration of action. He notes an imbalance of fluids or electrolyte levels, which can show up as dehydration, altered blood pressure, or electrolyte disturbances.
Dr. Setareh adds the risk of potassium and magnesium loss, as well as more frequent urination, as unique and common side effects of furosemide.
“Furosemide may cause more pronounced fluctuations in these areas due to its higher dosing variability and less consistent absorption rates compared to torsemide,” Dr. Dasgupta adds.
Patients should be sure to schedule a follow-up visit with a medical provider and possibly lab blood tests so they can assess how their body reacts to furosemide.
How to minimize furosemide side effects
To minimize those side effects, both doctors recommend closely monitoring hydration and electrolyte levels—especially in the first month after making the switch.
“Regularly scheduled blood tests may be necessary to adjust the dose to maintain balance,” Dr. Dasgupta says. “Staying well-hydrated and adhering to dietary recommendations regarding potassium and salt intake can also help mitigate risks.”
If someone experiences frequent urination as a side effect, Dr. Setareh encourages taking the medicine earlier in the day so they don’t have to get up at night when trying to sleep.
Can you take furosemide and torsemide together?
If these medications are the same in many ways, can someone take both?
“Generally, taking both torsemide and furosemide together is not recommended as they have similar functions, and combining them can increase the chance of severe dehydration and electrolyte imbalances,” Dr. Dasgupta says.
He adds that it would also be unproductive. In fact, it could be harmful, increasing the risk of adverse side effects.
Dr. Setareh agrees, noting the risk of excessive diuresis as well as the potential of dehydration and electrolyte imbalances. “They should be used individually, with careful monitoring, to manage fluid levels effectively,” he says.
So, healthcare providers prescribe one or the other.
The bottom line
Someone may want to switch from torsemide to furosemide because the latter is cheaper, available in more forms, has a longer duration of action, or for another reason. Dosage adjustments will be necessary, and side effects may occur. Be sure to talk to a medical provider for advice on safely switching to furosemide.
Sources
- To curb high rates of heart disease and stroke, experts urge prevention and innovation, American Heart Association (2024)
- Peripheral edema: A common and persistent health problem for older Americans, PloS One (2021)
- What is heart failure?, National Heart, Lung, and Blood Institute (2022)
- Raj Dasgupta, MD, the chief medical adviser for Fortune
- Sam Setareh, MD, a cardiologist at Cedars-Sinai Medical Center and director of clinical cardiology at Beverly Hills Cardiovascular
- Diuretic therapy in acute decompensated heart failure — bolus or continuous?, Indian Heart Journal (2014)
- Loop diuretic agent, Biomarkers in Technology (2019)
- Mechanistic differences between torsemide and furosemide, Journal of the American Society of Nephrology (2024)
- Effect of torsemide vs furosemide after discharge on all-cause mortality in patients hospitalized with heart failure: The TRANSFORM-HF randomized clinical trial, JAMA (2023)
- Effect of torsemide versus furosemide on symptoms and quality of life among patients hospitalized for heart failure: The TRANSFORM-HF randomized clinical trial, Circulation (2023)