Local anesthetics are effective, observational data indicate
Intravesical administration of local anesthetic agents—usually lidocaine—appears to provide significant relief from pelvic pain arising from IC. Only observational data on their use are available, however.
Treatment with these agents reflects the newer concept that IC-related pain may be neuropathic and that local anesthetics may down-regulate the bladder afferent nerves.11 Parsons noted that 80% of patients experienced pain relief after intravesical treatment with a therapeutic solution of 40,000 U of heparin, 8 mL of 2% lidocaine, and 3 mL of 8.4% sodium bicarbonate, given three times weekly for 2 weeks. Pain relief was sustained for at least 48 hours after the last instillation.
Lidocaine has also been used intravesically at a dosage of 20 mL of 1% solution. Most reports of local anesthetic usage have included heparin at dosages of 10,000 to 40,000 U, but not all have included the addition of sodium bicarbonate, which may increase absorption of local anesthetic agents into the bladder epithelium and improve efficacy.12 The instillation of local anesthetics is common in practice, but clinical trials are needed to confirm its safety and efficacy.
Consider an antihistamine if there is a history of allergy
Activated mast cells play a role in the inflammatory response of the bladder in many patients who have IC. Medications that stabilize and reduce mast cell activation may be effective, especially in patients who have a history of significant allergy. For example, in an open-label study, hydroxyzine reduced symptoms by 40% overall, but it reduced them by 55% in patients who had a history of significant allergy.13 PPS is a potent antihistamine, as well as an effective glycosaminoglycan in the bladder micellar formation. Hydroxyzine, like PPS, may have to be administered for several months before symptoms improve significantly, so patients should continue treatment for 3 to 6 months before making a decision about efficacy.
The one published randomized, clinical trial of hydroxyzine yielded a response rate of 31%, compared with 20% among patients who did not receive the drug, but this difference failed to reach statistical significance.14
Anticonvulsants are largely untested in treatment of IC
Several anticonvulsants have proved to be effective in the treatment of neuropathic pain. Although they have been suggested as a possible treatment for IC, their efficacy in this regard has not been well established.
Gabapentin is an anticonvulsant commonly used to treat pain. In an uncontrolled, open-label trial, the drug reduced pain in 10 (48%) of 21 patients who had IC, but four patients (20%) dropped out due to side effects.15
Is hormonal manipulation useful?
One observational study suggests that hormonal manipulation may improve bladder symptoms of IC.16 Twenty-three of 46 women in this series experienced a notable perimenstrual increase in IC-related pain. Fifteen of the 23 were treated with leuprolide acetate, a combined oral contraceptive, or hysterectomy with bilateral salpingo-oophorectomy. All but one also had a gynecologic diagnosis of endometriosis, pelvic congestion syndrome, or chronic pelvic inflammatory disease. Thirteen of the 15 experienced sustained improvement of symptoms attributed to IC. The bottom line: Consider cyclic suppression in patients who have a history of perimenstrual flare.
Three initial modalities yield good results
In our clinic, we tend to start patients on both PPS and amitriptyline. If the patient has a high level of pain, we include bladder instillation with lidocaine and heparin to see whether they provide immediate pain relief. More than 50% of our patients are adequately treated with these three modalities. The addition of other treatments depends on the patient’s response to and tolerance of these initial treatments.
Other nonbladder sources of pain should also be identified and treated, such as irritable bowel syndrome, endometriosis, vulvodynia, and pelvic floor tension myalgia.
The effectiveness of multimodality therapy has not been well studied. A great deal more research is needed, particularly randomized, placebo-controlled studies.
CASE RESOLVED: A multimodal approach alleviates severe pain
Twenty-five-year-old J. M. has just been given a diagnosis of IC/PBS. We advise her to avoid caffeine, carbonated drinks, alcoholic beverages, and acidic foods. We also prescribe oral PPS and teach her how to instill heparin and lidocaine into her bladder.
Because J. M. was given an earlier diagnosis of endometriosis, we also continue hormonal suppression with norethindrone acetate.
When her pain remains bothersome after 6 months, we add 600 mg of gabapentin each night.
Four years after her first visit to our office, J. M. reports pain levels that range from 0 to 4, with occasional flares to 4 with breakthrough bleeding. She now voids at intervals of 4 to 6 hours and reports no nocturia.