SIDE EFFECTS: Diarrhea, hair loss, nausea, headache, stomach upset, or abdominal pain may occur. If any of these effects persist or worsen, tell your doctor or pharmacist promptly.

Remember that your doctor has prescribed this medication because he or she has judged that the benefit to you is greater than the risk of side effects. Many people using this medication do not have serious side effects.

Tell your doctor immediately if any of these unlikely but serious side effects occur: unusual bruising/bleeding (e.g., blood in stool), mental/mood changes, heartburn, discomfort when swallowing.

Tell your doctor immediately if any of these rare but very serious side effects occur: tiredness, fast/pounding heartbeat, signs of infection (e.g., fever, persistent sore throat), shortness of breath, vision changes, eye pain, dark urine, yellowing eyes/skin, persistent nausea/vomiting.

A very serious allergic reaction to this drug is rare. However, seek immediate medical attention if you notice any symptoms of a serious allergic reaction, including: rash, itching/swelling (especially of the face/tongue/throat), severe dizziness, trouble breathing.

This is not a complete list of possible side effects. If you notice other effects not listed above, contact your doctor or pharmacist.

In the US -

Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

In Canada - Call your doctor for medical advice about side effects. You may report side effects to Health Canada at 1-866-234-2345.

Read the Elmiron (pentosan polysulfate sodium capsules) Side Effects Center for a complete guide to possible side effects »

PRECAUTIONS: Before taking pentosan polysulfate sodium, tell your doctor or pharmacist if you are allergic to it; or to heparin or low molecular weight heparin; or if you have any other allergies. This product may contain inactive ingredients, which can cause allergic reactions or other problems. Talk to your pharmacist for more details.

Before using this medication, tell your doctor or pharmacist your medical history, especially of: bleeding disorders (e.g., hemophilia, thrombocytopenia), blood vessel disorders (e.g., aneurysm), liver disease, spleen disorders, stomach/intestinal disorders (e.g., stomach ulcers, polyps, diverticula).

Before having surgery, tell your doctor or dentist that you are using this medication.

During pregnancy, this medication should be used only when clearly needed. Discuss the risks and benefits with your doctor.

It is not known whether this drug passes into breast milk. Consult your doctor before breast-feeding.