IC PaIN Trial: Interstitial Cystitis Pain Improvement With Naltrexone, the Effect of Low Dose Naltrexone on Symptoms and Pain of Patients With Interstitial Cystitis/Painful Bladder Syndrome a Randomized Placebo-controlled Prospective Trial

Interstitial cystitis/painful bladder syndrome (IC/PBS) is a debilitating condition with symptoms of urinary urgency, frequency, nocturia (waking up at night to void), and pain, without evidence of urinary tract infection or other identifiable causes. IC/PBS often coexists with other chronic pain syndromes, such as irritable bowel syndrome, chronic fatigue syndrome, and fibromyalgia.

Several treatments exist for IC/PBS; some are not effective, others are time consuming for patients to receive, some can take weeks to months before they become effective, and many have risks associated with them. Low-dose naltrexone (LDN) has demonstrated improvement of symptoms in conditions associated with IC/PBS. LDN is defined as less than 5mg of naltrexone. Some adverse effects have been reported with LDN, the most common are vivid dreams, nightmares, and insomnia.

The investigators hypothesis LDN will have greater than 30% reduction in symptoms as defined by the Interstitial Cystitis Symptom Index in patients diagnosed with IC/PBS from baseline when compared to placebo. The 30% reduction in pain is a standard outcome measure in the pain literature. This improvement has been seen in prior studies where LDN was used to treat pain syndromes.

This will be a randomized double-blinded placebo-controlled prospective trial. Patients meeting diagnostic criteria for IC/PBS by American Urologic Association (AUA) guidelines will be eligible, and then must then meet all applicable inclusion and exclusion criteria. Study participants will sign a consent, complete several questionnaires, give a blood sample to measure liver function tests, and once at home, complete a 24-hour bladder diary.

Participants will be randomized to receive either placebo or study medication. Participants will be instructed to take one capsule nightly for two weeks, then increase to two capsules nightly for four weeks. They will be given a log to record the date and time they take the medication. All study participants will also receive first-line behavioral therapy for IC/PBS of a bladder diet and bladder drills.

After six weeks, participants will complete a second bladder diary. They will then complete the exit study questionnaires, have a second liver function test, return any unused medication, and meet with their doctor to discuss conventional treatment options for IC/PBS.