Filspari (sparsentan) is prescribed for certain kidney problems. While it can be an effective treatment, it is important to know that Filspari can interact with other medicines and substances.
An interaction occurs when one substance changes how a medication affects the body. Understanding these interactions can help reduce the risk of side effects and help your medicine work as intended.
This article does not include all possible Filspari interactions. Always tell your health care provider and pharmacist about all prescription drugs, over-the-counter medicines, and any vitamins, herbs, or other supplements you use.
Understanding Filspari Interactions
After you take Filspari, your body processes it using certain enzymes in your liver and gut. Some medicines can affect how these enzymes work. This can change the amount of Filspari in your body. Filspari can also change how some of these enzymes work. This can affect the blood levels of some other medicines in your body.
Filspari may also work similarly to other medicines or have similar side effects to other medicines. These can lead to an increased risk of the same types of side effects.
While not a complete guide, below are more details about drug interactions to be aware of when taking Filspari.
1. Certain types of blood pressure medicines
Renin and angiotensin are hormones in your body that regulate blood pressure and fluid balance. Medicines that affect the renin-angiotensin system are often used to lower blood pressure or to treat certain heart or kidney problems. Filspari and these medicines have similar side effects.
Examples include:
- Aliskiren
- An angiotensin-converting enzyme (ACE) inhibitor, such as benazepril, captopril, enalapril, or lisinopril
- An angiotensin II receptor blocker (ARB), such as candesartan, irbesartan, losartan, olmesartan, or valsartan
Medicines that affect the renin-angiotensin system have side effects similar to those of Filspari. Taking them together can increase your risk of side effects, and some of them can be serious. Do not take these medicines together. If you take any of these medicines, tell your health care provider before you start taking Filspari.
2. Medicines for high blood pressure in the lungs
Endothelin receptor antagonists are commonly used to treat pulmonary arterial hypertension (PAH), a type of high blood pressure in the lungs. Filspari and these medicines have similar side effects.
Examples include:
- Ambrisentan
- Bosentan
- Macitentan
Taking Filspari along with any of these medicines that work similarly can increase your risk of side effects, and some of these side effects can be serious. Do not take these medicines together. If you take any of these medicines, tell your health care provider before you start taking Filspari.
3. Certain medicines to treat infections
Taking certain medicines to treat an infection may increase the amount of Filspari in your body.
Examples include:
- Clarithromycin
- Itraconazole
- Ketoconazole
These medicines slow down how your body breaks down Filspari. This can cause the medicine to build up, increasing the risk of side effects.
Because of this risk, these medicines should not be taken with Filspari. Your health care provider will likely recommend a different option.
4. Certain seizure medicines
Some seizure medicines may lower the amount of Filspari in your body.
Examples include carbamazepine and phenytoin.
These medicines can make your body break down Filspari faster. This may lower the amount of medicine in your body, making it harder for Filspari to protect your kidneys.
Because of this risk, these medicines should not be taken with Filspari. Your health care provider will likely recommend a different option.
5. Certain calcium channel blockers
Some calcium channel blockers may increase the amount of Filspari in your body.
Examples include diltiazem and verapamil.
These medicines slow down how your body breaks down Filspari. This can cause the medicine to build up, increasing the risk of side effects.
If these medicines need to be taken together, your health care provider may monitor you more closely for side effects or adjust your treatment.
6. Nonsteroidal anti-inflammatory drugs (NSAIDs)
NSAIDs are used for fever, pain, and inflammation. Taking Filspari with an NSAID can increase your risk for side effects.
Examples include:
Both Filspari and NSAIDs can lead to kidney damage. Taking them together can further raise this risk.
Talk to your health care provider before taking Filspari with an NSAID. If you need to take them together, your health care provider may monitor you more closely for side effects.
7. Digoxin
Digoxin is used for certain heart problems. Filspari can increase the amount of digoxin in your body.
Filspari may slow down how your body breaks down digoxin. This can cause the medicine to build up and increase the risk of side effects.
If these medicines need to be taken together, your health care provider may monitor you more closely for side effects or adjust your treatment.
8. Bupropion
Bupropion is used for certain types of depression or to help stop smoking. Taking Filspari with bupropion can decrease the amount of bupropion in your body.
Filspari can make your body break down bupropion faster. This can lessen the amount of bupropion in your body and make it less effective.
If these medicines need to be taken together, your health care provider may monitor you more closely to make sure bupropion is working or may adjust your treatment.
9. Potassium-sparing diuretics
Diuretics or water pills are used to help lower blood pressure or treat fluid buildup or edema. Taking Filspari with potassium-sparing diuretics can increase your risk for side effects.
Examples of potassium-sparing diuretics include spironolactone and triamterene. They help get rid of extra fluid without removing potassium. Filspari can lead to high potassium levels. If you take them together, you may have an increased risk of high potassium levels.
If these medicines need to be taken together, your health care provider may monitor you more closely for side effects or adjust your treatment.
Other Interactions With Filspari
Alcohol
Combining alcohol and Filspari may increase your risk of dizziness, which is a common side effect of Filspari. It is best to limit or avoid alcohol while taking Filspari.
Supplement interactions
Some supplements may interact with Filspari.
Examples include:
- Potassium supplements
- Salt substitutes
- St. John’s wort
Talk to your health care provider if you take a potassium supplement or use any salt substitutes. These can increase your potassium level, and so can Filspari. Taking them together might make your potassium level too high.
The drugmaker of Filspari hasn’t listed St. John’s wort as an interaction in the medicine’s labeling. But St. John’s wort may increase how quickly your body processes Filspari. This may lower the amount of medicine in your body and make it less effective for protecting your kidneys. Because of this risk, St. John’s wort should not be taken with Filspari. Your health care provider will likely recommend a different option.
Other herbal and dietary supplements may cause interactions. Tell your health care team about all supplements you take.
Food interactions
Filspari should be taken before either your morning or evening meal.
Certain foods may interact with Filspari, including grapefruit or grapefruit juice.
Eating grapefruit or drinking grapefruit juice while taking Filspari may increase your risk of side effects. It is best to limit or avoid grapefruit and grapefruit juice while taking Filspari.
How to Avoid Filspari Interactions
You can lower your risk of drug interactions with Filspari by doing a few simple things. To lower your risk:
- Take Filspari exactly as prescribed.
- Keep an updated medication list and share it with your health care team.
- Inform your health care provider and pharmacist about any vitamins, herbs, or other supplements you are using.
- Limit the use of salt substitutes.
- Limit your intake of grapefruit, grapefruit juice, and alcohol.
Your health care provider can help decide whether Filspari is safe for you and make sure your treatment plan is changed if needed.