Proper Use

Take this medicine on an empty stomach (at least 1 hour before or 2 hours after meals) and at least 1 hour before or after any other food, milk, or medicine. Also, always take it with a full glass (8 ounces) of water.

Sometimes pentosan must be taken for up to 3 to 6 months before you begin to feel better. Your doctor should check your progress at regular visits during this time.

It is important that you follow any special instructions from your doctor. Some foods and beverages may aggravate your condition. Also, make certain your doctor knows if you are on any special diet, such as a low-sodium or low-sugar diet.


The dose of this medicine will be different for different patients. Follow your doctor's orders or the directions on the label. The following information includes only the average doses of this medicine. If your dose is different, do not change it unless your doctor tells you to do so.

The amount of medicine that you take depends on the strength of the medicine. Also, the number of doses you take each day, the time allowed between doses, and the length of time you take the medicine depend on the medical problem for which you are using the medicine.

  • For oral dosage form (capsules):
    • To treat interstitial cystitis:
      • Adults—100 milligrams (mg) three times a day for three months. Your doctor may tell you to repeat this dose.
      • Children—Use and dose must be determined by your doctor.

Missed Dose

If you miss a dose of this medicine, take it as soon as possible. However, if it is almost time for your next dose, skip the missed dose and go back to your regular dosing schedule. Do not double doses.


Store the medicine in a closed container at room temperature, away from heat, moisture, and direct light. Keep from freezing.

Ask your healthcare professional how you should dispose of any medicine you do not use.

Keep out of the reach of children.

Do not keep outdated medicine or medicine no longer needed.