- What is pentosan, and how does it work (mechanism of action)?
- What are the uses for pentosan?
- What are the side effects of pentosan?
- What is the dosage for pentosan?
- What drugs or supplements interact with pentosan?
- Is pentosan safe to take if I'm pregnant or breastfeeding?
- What else should I know about pentosan?
What is pentosan, and how does it work (mechanism of action)?
Pentosan is a semi-synthetic (man-made) drug that resembles the anticoagulant ("blood thinner") heparin and is used for treating the symptoms of interstitial cystitis. Interstitial cystitis is a condition, usually of unknown cause, in which there is inflammation of the urinary bladder that most frequently causes pelvic pain and frequent urination. The exact mechanism whereby pentosan reduces the symptoms of interstitial cystitis also is unknown; however, scientists believe that pentosan may coat the lining of the bladder and prevent irritating substances in the urine from reaching the cells of the lining. The FDA approved pentosan in September 1996.
What brand names are available for pentosan?
Elmiron
Is pentosan available as a generic drug?
GENERIC AVAILABLE: No
Do I need a prescription for pentosan?
Yes
What are the uses for pentosan?
Pentosan is used to treat the pain or discomfort of interstitial cystitis.
What are the side effects of pentosan?
The most common side effects of pentosan are:
Other important side effects include abnormalities of liver tests in the blood. Bleeding from the rectum and other areas also may occur.

SLIDESHOW
Urinary Incontinence in Women: Types, Causes, and Treatments for Bladder Control See SlideshowWhat is the dosage for pentosan?
The recommended dose of pentosan is 100 mg three times daily (every 8 hours) taken at least one hour before or two hours after meals so that food does not retard its absorption. Patients should be evaluated after 3 months, and treatment may be continued for another three months if patients have not improved and they are tolerating pentosan.
What drugs or supplements interact with pentosan?
Pentosan is a weak anticoagulant (blood thinner) which may increase bleeding.
Call your doctor if you will be undergoing surgery or will begin taking anticoagulant therapy such as warfarin sodium, heparin, high doses of aspirin, or anti-inflammatory drugs such as ibuprofen.
Is pentosan safe to take if I'm pregnant or breastfeeding?
Studies of pentosan have not been conducted in nursing mothers.
Summary
Pentosan (Elmiron) is a medication prescribed for the treatment of interstitial cystitis. Review side effects, drug interactions, pregnancy safety, and dosage information prior to taking this medication.
Treatment & Diagnosis
Medications & Supplements
Prevention & Wellness

Report Problems to the Food and Drug Administration
You are encouraged to report negative side effects of prescription drugs to the FDA. Visit the FDA MedWatch website or call 1-800-FDA-1088.