Filspari side effects and safety information
Filspari (sparsentan) is a prescription medication used to help manage IgA nephropathy (IgAN) in adults. It’s also used to reduce proteinuria in some adults and children ages 8 years and older with focal segmental glomerulosclerosis (FSGS). While this medication is a safe and effective option for many people, understanding its potential side effects is part of a successful treatment plan.
By staying informed about how Filspari interacts with your body, you can work more effectively with your healthcare team to monitor your progress and address any concerns early.
Keep reading to learn about some of the side effects associated with Filspari, including its boxed warnings.
Many people taking Filspari tolerate it well, but there are some common side effects to be aware of. In clinical trials, the most common side effects were typically related to how the drug affects fluid balance and blood pressure.
While common side effects are often mild, there are serious reactions that require immediate medical attention.
Filspari affects the way blood flows through the kidneys. In some cases, this can cause a temporary or permanent kidney damage. Your doctor will check your kidney function (specifically creatinine levels) throughout treatment to ensure your kidneys are responding appropriately to the medication.
High potassium is a known risk for people with kidney disease, and Filspari can increase this risk further. Because severe hyperkalemia can affect heart rhythm, your doctor will check your potassium levels regularly. They may advise you to limit high-potassium foods or adjust other medications that also increase potassium.
Beyond mild swelling, some people may experience more significant fluid retention. This can be particularly concerning for those with a history of heart failure. If you experience sudden weight gain or difficulty breathing, notify your care team immediately.
If your blood pressure drops too low, you may feel dizzy or lose your balance. This risk is higher if you are also taking diuretics (water pills) or if you are dehydrated.
Quick note: As with any drug, Filspari may cause an allergic reaction. But this side effect wasn’t reported in the drug’s clinical trials.
Experiencing side effects? After the Food and Drug Administration (FDA) approves a drug, it tracks and reviews its side effects. If you develop a side effect while taking this medication and want to report it to the FDA, you can visit MedWatch or call 800-FDA-1088.
The Food and Drug Administration (FDA) has issued two boxed warnings for Filspari: the risk of liver injury and the risk of serious pregnancy complications (including birth defects). Because of these risks, Filspari is only available through a restricted distribution program called the Filspari REMS (Risk Evaluation and Mitigation Strategy) program.
Filspari can cause elevated liver enzymes, which may indicate liver injury. Before you start treatment, your healthcare professional will order blood tests to check your liver function. These tests (ALT, AST, and bilirubin) will be repeated every 3 months throughout your treatment.
Filspari can cause major birth defects if taken during pregnancy. If you are able to become pregnant, your doctor will have you take a pregnancy test before treatment. They’ll also advise using an effective form of birth control for the duration of treatment and 2 weeks after your final dose.
Filspari is a dual endothelin and angiotensin II receptor blocker (ARB). Because of the way it works, it can interact with several other substances.
Due to the risk of interactions with Filspari, it’s important to talk with your doctor about your health history. This includes any medications or supplements you’re taking and any other health conditions you may have.
Combining these medications increases the risk of certain side effects from Filspari, including low blood pressure and kidney injury.
Alcohol wasn’t reported to interact with Filspari in the drug’s clinical trials. However, alcohol can lower your blood pressure and increase dizziness. Since Filspari also lowers blood pressure, it’s important to talk with your doctor about how much alcohol — if any — is safe to drink during treatment.
Alcohol wasn’t reported to interact with Filspari in the drug’s clinical trials. However, alcohol can lower your blood pressure and increase dizziness. Since Filspari also lowers blood pressure, it’s important to talk with your doctor about how much alcohol — if any — is safe to drink during treatment.
Filspari does not typically cause fat-based weight gain, but it can cause “water weight” gain due to fluid retention.
Filspari does not typically cause fat-based weight gain, but it can cause “water weight” gain due to fluid retention.
Filspari is a targeted treatment that can help protect kidney function in people with certain conditions, but it requires regular monitoring to remain safe and effective. It’s important to attend your follow-up appointments and let your doctor know if you experience any severe or bothersome side effects.
By maintaining an open line of communication with your healthcare team, you can manage these potential side effects while focusing on the long-term health of your kidneys.
Disclaimer: While Medical News Today strives for factual, comprehensive, and current information, this article is not a substitute for a licensed healthcare professional’s expertise. Always consult a doctor before taking or discontinuing any medication. Drug information is subject to change and may not cover all uses, directions, precautions, warnings, interactions, reactions, or adverse effects. The lack of a warning does not guarantee a drug’s safety, effectiveness, or appropriateness for all patients or specific uses. Learn more about our approach to content integrity.