Pronunciation: spar-SEN-tan
Brand name: Filspari
Dosage form: Tablet (200mg, 400mg)
Drug class: Miscellaneous cardiovascular agents

Medically reviewed by Melisa Puckey, BPharm. Last updated on Jun 12, 2025.

What is sparsentan?

Sparsentan is an FDA-approved medication used to treat primary immunoglobulin A nephropathy (IgAN) to help maintain kidney function and reduce protein in urine (proteinuria).  Sparsentan is a dual endothelin and angiotensin II receptor antagonist.

Sparsentan brand name is Filspari, by Travere Therapeutics.

Sparsentan is an oral tablet that is taken once a day.

Sparsentan FDA approval

Sparsentan FDA approval is to treat adults with primary immunoglobulin A nephropathy (IgAN) who are at risk for disease progression. Sparsentan FDA approval was granted on February 17, 2023, as an accelerated approval, with a full FDA approval granted on September 05, 2024.  Full FDA approval was based on long-term positive results from the clinical trial PROTECT (NCT03762850), which demonstrated that sparsentan significantly slowed kidney function decline over two years compared to irbesartan.

What is immunoglobulin A nephropathy?

Immunoglobulin A nephropathy (IgAN) is a rare autoimmune kidney disease where proteins from your immune system, called IgA  (Immunoglobulin A), cause inflammation and kidney damage. This causes blood and protein to leak into the urine. Over time, some patients with ongoing proteinuria risk progressing to kidney failure, which may require maintenance dialysis or kidney transplantation.

How does Sparsentan work?

Filspari works by blocking two pathways thought to contribute to kidney damage in IgAN, the endothelin-1 and angiotensin II pathways. Sparsentan mechanism of action is by selectively targeting and blocking the angiotensin-II-type-I (AT1R) and endothelin-1-type A receptor (ETAR), reducing inflammation in the kidneys and protein in the urine.

Sparsentan class of medicine is a dual endothelin angiotensin receptor antagonist (DEARA).

 Sparsentan REMS

Sparsentan is only available through a restricted distribution program called Filspari Risk Evaluation and Mitigation Strategies (REMS), because of the risk of liver toxicity and harm to an unborn baby. Only prescribers certified in REMS can prescribe Filspari, and all patients must enroll in the Filspari REMS before starting treatment and comply with monitoring requirements.

Pharmacies that dispense Sparsentan must be certified with Filspari REMS and must dispense only to patients authorized to receive the medicine. Your healthcare provider will give you all the details.

Sparsentan side effects

Common sparsentan side effects

Common side effects of sparsentan may include:

• dizziness;
• swelling of hands, legs, ankles, and feet; or anemia (low red blood cells).

Serious sparsentan side effects

Get emergency medical help if you have signs of an allergic reaction, such as hives, difficulty breathing, swelling of your face, lips, tongue, or throat.

Sparsentan may cause serious liver problems. Stop taking sparsentan and call your doctor right away if you have nausea, vomiting, loss of appetite, right-sided upper stomach pain, tiredness, weight loss, jaundice, dark urine, fever, or itching.

Sparsentan may cause other serious side effects. Call your doctor at once if you have:

• a light-headed feeling, like you might pass out;
• kidney problems - swelling, urinating less, feeling tired or short of breath;
• high blood potassium - nausea, weakness, tingly feeling, chest pain, irregular heartbeats, loss of movement; or
• fluid retention - shortness of breath (even while lying down), swelling, rapid weight gain (especially in your face and midsection).

This is not a complete list of side effects, and others may occur. Call your doctor for medical advice about side effects. You may report side effects to the FDA at 1-800-FDA-1088.

Related/similar drugs

Warnings

Do not use if you are pregnant. Use effective birth control.

Tell your doctor about all your other medicines. Some drugs should not be used with sparsentan.

Sparsentan may cause serious liver problems. Stop taking sparsentan and call your doctor right away if you have nausea, vomiting, loss of appetite, right-sided upper stomach pain, tiredness, weight loss, jaundice, dark urine, fever, or itching.

Sparsentan is available only under a special program called Filspari Risk Evaluation and Mitigation Strategies (REMS). You must be registered in the program and understand the risks and benefits of this medicine.

Before taking this medicine

Some drugs should not be used with sparsentan. Your treatment plan may change if you also use:

• aliskiren;
• medicine to treat high blood pressure in the lungs--macitentan, bosentan, ambrisentan and others; or
• heart or blood pressure medication--enalapril, candesartan, lisinopril, irbesartan, losartan, olmesartan, valsartan, telmisartan.

Also see the "What other drugs will affect sparsentan?" section.

Tell your doctor if you have ever had:

• high blood pressure;
• heart problems; or
• liver or kidney disease.

Pregnancy

Do not use this medicine if you are pregnant. It may cause birth defects. You must use effective birth control while using sparsentan and for at least 1 month after your last dose. Tell your doctor if you become pregnant.

Ask your doctor about the best form of birth control while you are using sparsentan. See more about effective birthcontrol options in the Medication Guide. You will need to have a negative pregnancy test before starting this treatment. You will need to take a pregnancy test during and after treatment with sparsentan.

Breastfeeding

Do not breastfeed while take this medicine

How should I take sparsentan?

Follow all directions on your prescription label and read all medication guides or instruction sheets. Your doctor may occasionally change your dose. Use the medicine exactly as directed.

Sparsentan is usually taken once per day. Follow your doctor's dosing instructions very carefully.

Swallow the tablet whole with a full glass of water before a meal. Take it the same way each time. Drink plenty of liquids while you are taking sparsentan.

Your condition may get worse if you stop using sparsentan suddenly. Ask your doctor before stopping the medicine.

You may need frequent medical tests, even if you have no symptoms.

You will need frequent blood tests to check your liver function, and your next dose may be delayed based on the results.

Store at room temperature away from moisture and heat. Store sparsentan in the original container.

Sparsentan dosing information

Usual Adult Dose for Primary Immunoglobulin A Nephropathy:

Initial dose: 200 mg orally once a day for 14 days
Maintenance dose: Following the initial dose, increase to 400 mg orally once a day, as tolerated

Comments:
Consider dose titration when resuming treatment after interruption: Start with the initial dose for 14 days, then increase to the recommended maintenance dose.

Dose may need modification with liver problems or drug interactions.

Use: To reduce proteinuria in adults with primary immunoglobulin A nephropathy at risk of rapid disease progression 

What happens if I miss a dose?

Skip the missed dose and use your next dose at the regular time. Do not use two doses at one time.

What happens if I overdose?

Seek emergency medical attention or call the Poison Help line at 1-800-222-1222.

What should I avoid while taking sparsentan?

Do not take potassium supplements or use salt substitutes, unless your doctor has told you to.

Do not take with angiotensin receptor blockers (ARBs), endothelin receptor antagonists (ERAs), or aliskiren.

Grapefruit may interact with sparsentan and cause side effects. Avoid consuming grapefruit products.

What other drugs will affect sparsentan?

Sometimes it is not safe to use certain medicines at the same time. Some drugs can affect your blood levels of other drugs you use, which may increase side effects or make the medicines less effective.

Avoid taking an antacid within 2 hours before or after you take sparsentan.

Do not take with angiotensin receptor blockers (ARBs), endothelin receptor antagonists (ERAs), or aliskiren. 

Drug interactions occur with strong CYP3A inhibitors, moderate CYP3A inhibitors, strong CYP3A inducers, antacids, acid-reducing agents, non-steroidal anti-inflammatory drugs (NSAIDs), CYP2B6, 2C9, and 2C19 substrates, sensitive P-gp and BCRP substrates, and agents increasing serum potassium.

Tell your doctor about all your current medicines. Many drugs can affect sparsentan, especially:

• blood pressure or heart medications;
• a diuretic or "water pill" that may increase blood potassium, such as spironolactone, triamterene, amiloride; or
• NSAIDs (nonsteroidal anti-inflammatory drugs) - aspirin, ibuprofen (Advil, Motrin), naproxen (Aleve), celecoxib, diclofenac, indomethacin, meloxicam, and others.

This list is not complete. Other drugs may affect sparsentan, including prescription and over-the-counter medicines, vitamins, and herbal products. Not all possible drug interactions are listed here.

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

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