[Effect of distigmine at 5 mg daily in patients with detrusor underactivity]

Since distigmine can cause the serious side effect of cholinergic crisis, its dosage regimen has been reduced to 5 mg/day for patients with difficulty in urination due to detrusor underactivity. Therefore, the efficacy and safety of add-on therapy with distigmine at 5 mg daily were examined in patients with persistent urination problems due to detrusor underactivity despite administration of alpha1-blockers.

The subjects were 39 patients with underactive bladder (18 men and 21 women with an average age of 75 years) who showed no improvement of difficulty in urination or had a residual urine volume > or = 50 ml despite the administration of alpha1-blockers for more than 4 weeks. They received treatment with distigmine (5 mg daily after breakfast) in addition to their alpha1-blockers for 8 weeks. The international prostate symptom score (IPSS), quality-of-life (QOL) score, residual urine volume, blood pressure, and biochemistry tests were investigated before and after addition of distigmine.

After four and eight weeks of distigmine administration, all items of the IPSS and QOL score, as well as the residual urine volume, showed a significant decrease. In contrast, the pressure and pulse rate were unchanged. Serum creatinine showed a slight but significant decreased. As adverse events, frequent defecation, fecal incontinence, diarrhea, frequent urination and poor physical condition were recognized in 4 patients, but there was no serious event.

For difficulty in urination due to detrusor underactivity, the combination of an alpha1-blocker with distigmine at 5 mg daily showed early efficacy and good safety.