Gabapentin for overactive bladder and nocturia after anticholinergic failure

We reviewed our experience with the use of gabapentin to treat symptoms of overactive bladder (OAB) and nocturia in patients who have failed conventional anticholinergic therapy.

Thirty-one patients referred to us with refractory (OAB) and/or nocturia were treated with oral gabapentin. All the patients had tried or remained on antimuscarinic drugs during treatment. Twenty-four of 31 complained of bothersome symptoms during day and night and the other seven had primary complaints of nocturia. Initial gabapentin doses ranged from 100-300 mg at bedtime. Dose was slowly titrated up to 3,000 mg based on patients' symptomatology and tolerability.

The mean age was 51 years old (range 27-78). There were 13 men and 18 women. The median steady state dose chosen by the patient after initial titration was 600 mg/day. Fourteen of 31 patients reported subjective improvement of their frequency and 8 have been on the medication for over 12 months with persistent efficacy. For the 14 improved patients, mean frequency/24 hours decreased from 14.1 +/- 2.2 to 10.0 +/- 2.1. Three patients with primary nocturia reported improvement from a mean of 4.0 +/- 1.3 to 1.0 +/- 0.3 episodes/night. Six patients stopped taking the drug within one month due to side effects mostly described as drowsiness or lethargy.

Fourteen of 31 patients with refractory (OAB) and nocturia improved with oral gabapentin. Gabapentin was generally well tolerated and can be considered in selective patients when conventional modalities have failed.