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Generic name: crofelemer [ kroe-FEL-e-mer ]
Brand names: Mytesi, Fulyzaq
Dosage form: oral delayed release tablet (125 mg)
Drug class: Antidiarrheals

Medically reviewed by on Mar 21, 2023. Written by Cerner Multum.

What is crofelemer?

Crofelemer is used in adults to treat diarrhea that may be caused by taking antiviral medicine to treat HIV (human immunodeficiency virus). Crofelemer is not for use in treating diarrhea that is caused by an infection.

Crofelemer is not a treatment for HIV.

Crofelemer may also be used for purposes not listed in this medication guide.


Follow all directions on your medicine label and package. Tell each of your healthcare providers about all your medical conditions, allergies, and all medicines you use.

Before taking this medicine

Tell your doctor if you are sick with diarrhea and vomiting or other symptoms of infection.

It is not known whether crofelemer will harm an unborn baby. Tell your doctor if you are pregnant or plan to become pregnant.

Women with HIV or AIDS should not breastfeed a baby. Even if your baby is born without HIV, the virus may be passed to the baby in your breast milk.

Crofelemer is not approved for use by anyone younger than 18 years old.

How should I take crofelemer?

Before you start treatment with crofelemer, your doctor may perform medical tests to make sure you do not have infectious diarrhea.

Follow all directions on your prescription label and read all medication guides or instruction sheets. Use the medicine exactly as directed.

Swallow the tablet whole and do not crush, chew, or break it.

You may take crofelemer with or without food.

Store at room temperature away from moisture and heat.

What happens if I miss a dose?

Take the medicine as soon as you can, but skip the missed dose if it is almost time for your next dose. Do not take 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 crofelemer?

Follow your doctor's instructions about any restrictions on food, beverages, or activity.

Crofelemer side effects

Get emergency medical help if you have signs of an allergic reaction: hives; difficult breathing; swelling of your face, lips, tongue, or throat.

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

  • dark urine, jaundice (yellowing of the skin or eyes);

  • wheezing, chest tightness, trouble breathing; or

  • worsening diarrhea.

Common side effects of crofelemer may include:

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 FDA at 1-800-FDA-1088.

Crofelemer dosing information

Usual Adult Dose for Diarrhea:

125 mg orally twice daily

Use: For symptomatic relief of noninfectious diarrhea in adult patients with HIV/AIDS on antiretroviral therapy:

What other drugs will affect crofelemer?

Other drugs may affect crofelemer, including prescription and over-the-counter medicines, vitamins, and herbal products. Tell your doctor about all your current medicines and any medicine you start or stop using.

Further information

Remember, keep this and all other medicines out of the reach of children, never share your medicines with others, and use this medication only for the indication prescribed.

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