A list of other medicines that may be prescribed to relieve IC symptoms follows. Each of these classes of medicines comes with its own set of side effects and drug interactions. Remember to always make sure that you check with your doctor before trying any new medicine or therapy.

Alpha Blockers

Certain alpha blockers are used to treat benign prostatic hyperplasia (prostate enlargement) in men in the United States. The drugs include:

  • Doxazosin (Cardura)
  • Terazosin (Hytrin)
  • Tamsulosin (Flomax)

Two of these, Cardura and Hytrin, and another not on the US market, alfuzosin, have been studied in chronic prostatitis and have been found to help reduce overall symptoms or pain.

Researchers are discovering that many men with this condition have glomerulations or Hunner’s ulcers on the bladder walls, and some researchers think that IC and chronic prostatitis (at least for a subset of men with chronic prostatitis) may really be the same. This is why some doctors are also trying these alpha blocker medicines in women with IC.


Dextroamphetamine sulfate (Desedrine)is a stimulant that promotes wakefulness and reduces appetite. It is approved for use in attention deficit hyperactivity disorder (ADHD) and narcolepsy. In 2005, case reports of two women with IC found dexamphetamine to be helpful in treating their symptoms. The hypothesis is that dextroamphetamine may help certain people with IC who experience idiopathic edema, a type of swelling of bodily tissues due to excess fluid retention.


Originally developed as an anti-seizure medicine, gabapentin (neurontin) is also used to treat nerve-related pain. Some types of IC pain may to be generated by nerve endings and the central nervous system. A few small studies showed that gabapentin may improve symptoms in some IC patients.

Histamine Blockers

Most antihistamines prescribed for allergy and IC are called “H1” blockers. When histamines bind to the histamine receptors on cells, that produces an allergic reaction. The H1 receptors aren’t the only ones that histamines go to, however. They can also bind to H2 receptors, and drugs that block these receptors can also be helpful in calming allergic reactions. H2 blockers include

  • Cimetidine (Tagamet)
  • Ranitidine (Zantac)
  • Nizatidine (Axid)
  • Famotidine (Pepcid)

By blocking these H2 receptors in the gut, these medicines reduce stomach acid secretions and, thus, stomach pain. Studies with one of these H2 blockers, cimetidine, showed it reduced bladder pain as well, maybe because of the histamine-blocking action. But why it works in IC really isn’t so clear. In two small studies (one with 9 and one with 14 patients), Tagamet reduced bladder pain for 40 to 60 percent of the IC patients.

In Japan, Suplatast tosilate, also known as IPD-1151T and available is indicated for IC, as well as asthma and allergies. This medicine acts somewhat earlier in the allergic process than histamine or leukotriene blockers do by affecting IgE. Suplatast tosilate helps suppress the production of IgE. It also helps to block production of cytokines and suppresses allergy-related eosinophils. This medicine remains under investigation in the US.

Tagamet, Zantac, Axid, and Pepcid are available over the counter.

Leukotriene Inhibitors

Leukotrienes which are substances produced by some immune system cells and mast cells, promote inflammation. Drugs that block leukotrienes are fairly new and are being used in the treatment of asthma and allergy. They include the prescription medicines:

  • Montelukast (Singulair)
  • Zafirlukast (Accolate)
  • Zileuton (Zyflo)

Some studies have implicated leukotrienes in inflammation of the bladder in IC. The receptors have been found in the bladder muscle in IC patients. A study of 10 IC patients in Denmark who took Singulair for three months showed significant reductions in frequency and pain.


Misoprostol (Cytotec) is an oral prostaglandin (a protective hormone-like substance found throughout the body). It inhibits the secretion of stomach acid and is often given to counteract the side effects of certain pain relievers such as aspirin and non-steroidal anti-inflammatory drugs (NSAIDS) like naproxen sodium (Naprosyn) or ibuprofen (Motrin), which can cause gastrointestinal problems. One European study found that misoprostol may help to treat IC by reducing inflammation.

Urinary Antacids

Citrates, which include potassium or sodium citrate, tricitrates, and citric acid, either alone or in combination (Bicitra, Citrolith, Oracit, Polycitra, Urocit-K), are usually used to prevent certain types of kidney stones. But because they make the urine less acidic, they may help relieve bladder pain. These are available by prescription.

Antimuscarinics (“gotta go” medicines)

Antimuscarinics are drugs that help relax muscles in the bladder and urinary tract and may help with urinary frequency and urgency. These medicines include:

  • Detrol LA
  • Ditropan XL
  • Flavoxate (Urispas)
  • Gelnique
  • Sanctura
  • Toviaz
  • VESIcare

Revised Wednesday, March 25th, 2015