Interstitial Cystitis and the Potential Role of Gabapentin

Hans C. Hansen, MD, Pain Relief Centers, PA, Hickory, NC, and the Department of Anesthesia, Wake Forest University School of Medicine, Winston Salem, NC.

South Med J. 2000;93(2) 

In This Article

Treatment

Treatment of the interstitial cystitis inflammatory process and its subsequent destruction of bladder tissue begins with inhibition of mast cell degranulation.[7] Hydroxyzine blocks mast cell secretion and inhibits the H1 receptor. Histamine release is inhibited, which may decrease the resultant hyperemia and fibrosis.

Clinical improvement with antihistamines often is unsuccessful as a monotherapy. Nonsteroidal anti-inflammatory drugs inhibit the synthesis of prostaglandins and may relieve symptoms in some patients. However, nonsteroidal anti-inflammatory drugs also have been shown to release histamine, which is an undesirable side effect in this patient population. Intravesicular heparin therapy is commonly used to further inhibit mast cell secretion and minimize the inflammatory process.[8]

Other treatments of interstitial cystitis include intravesicular installation of dimethyl sulfoxide (DMSO) to achieve remission of the inflammatory response.[1] Dimethyl sulfoxide is an anti-inflammatory agent, analgesic, and muscle relaxant. It also inhibits mast cell secretion and dissolves collagen.

Additional reports[9] have suggested using nifedipine, absolute alcohol instillation, hydrocortisone, oral steroids, and a variety of other agents as therapeutic options for interstitial cystitis, but prolonged improvement has not been documented by outcome studies. Transcutaneous electrical nerve stimulation has been reported to improve pain perception, but clinical experience does not suggest enhanced function or improved activities of daily living with this treatment.[10]

Many patients with interstitial cystitis have related depression, and amitriptyline would be a reasonable cotherapeutic agent to consider. Tricyclic antidepressants also inhibit histamine secretion from mast cells. Doxepin, a potent antihistamine, is a useful alternative to amitriptyline with fewer side effects. Both agents are anticholinergic and are considered to have modest central pain modulating properties. Interstitial cystitis patients are deprived of restorative sleep, and both agents are useful for this purpose.

Interstitial cystitis shares many common features of sympathetically maintained pain, otherwise known as reflex sympathetic dystrophy (RSD). In fact, interstitial cystitis has been described as a form of sympathetic dystrophy.[3] Gabapentin, an Food and Drug Administration-approved antiepileptic agent, is emerging as an excellent cotherapeutic medication to treat many painful conditions, including neuropathic pain and the sympathetically maintained pain of RSD. The addition of an anti-epileptic agent is routinely incorporated into RSD treatment profiles. Because of the safety profile of gabapentin, this drug is a superior alternative to carbamazepine, phenytoin, and valproic acid for the management of neuropathic pain and RSD.

The use of gabapentin in interstitial cystitis is supported by reports that this disease contains both a paleospinothalamic and neospinothalamic mechanism of pain.[3] Paleospinothalamic pain is a phylogenetically older pain pathway, which is responsive to narcotic therapy (Table 4). Neospinothalamic pain is often resistant to narcotics and typically defies conventional pain therapy. Neospinothalamic pain, however, does respond to antiepileptic agents, antidepressants (tricyclic, serotonin reuptake inhibitors), and occasionally higher dose narcotic therapy. I report two such cases in which patients with long-standing interstitial cystitis improved substantially with gabapentin therapy.

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