Alpha-blocker may benefit subset of women with LUTS

November 1, 2005

Vancouver, British Columbia--A subset of women with lower urinary tract symptoms—namely, those with AUA symptom scores in the severe range—may benefit from treatment with an alpha-blocker, according to findings from a small, multicenter study. In a general population of women with LUTS, treatment with the alpha-blocker, tamsulosin (Flomax) showed favorable but not statistically significant results compared with placebo.

Women with LUTS are often treated with antimuscarinic drugs, regardless of whether their predominant symptoms were indicative of storage or voiding symptoms, said lead author Anurag K. Das, MD, visiting associate professor of surgery at Harvard Medical School and director of the Center for Neuro-urology and Continence at Beth Israel Deaconess Medical Center in Boston. However, antimuscarinic drugs probably do not improve voiding (obstructive) symptoms and may cause them to worsen, he said.

Anecdotally, tamsulosin, a selective alpha-blocker, has provided symptomatic improvement to women whose symptoms are mostly related to voiding rather than storage, possibly because of its relaxation of the bladder neck, said Dr. Das. However, no large, controlled trials have been carried out.

The current study, presented in a poster at the AUA Western Section annual meeting, faced two key challenges. One was the lack of a validated female LUTS questionnaire for categorizing symptoms as voiding- or storage-related. The Bristol Female LUTS Questionnaire (BFLQ) was still undergoing validation when the study began 4 years ago, said Dr. Das. Therefore, the AUA Symptom Index (AUA SI) was used.

Another challenge was recruitment. Because tamsulosin is an FDA-approved drug (for the treatment of BPH in men), many women did not want to enter the trial and risk assignment to the placebo group, Dr. Das explained.

Mild improvement seen

In the 8-week, double-blind trial, a total of 70 women >18 years of age with a total AUA symptom score >13 and AUA obstructive score >5 were randomly assigned to placebo (33 women) or tamsulosin, 0.4 mg, once daily (37). All patients had been diagnosed with hesitancy, intermittency, difficulty in bladder emptying, or straining to void. Exclusion criteria were active urinary tract infections within the previous 6 months, a significant prolapse beyond the hymenal ring, urinary tract calculi, ureteral colic or mechanical outlet obstruction within 3 months of the study, bladder, vaginal or urethral surgery within 6 months of the study, neurogenic bladder, or taking anticholinergic medications for other urologic conditions within 2 weeks of the study.

The change in baseline AUA SI from the total score at day 56 was calculated using an analysis of covariance. The overall change from baseline score was not statistically significant between the placebo and tamsulosin groups (–4.0 and –5.2, respectively).

However, in a subset of patients with a total AUA score >20, the researchers observed a statistically significant difference in change from baseline score of –8.7 for the tamsulosin group compared with –2.8 for the placebo group (p=.017).

Patients treated with tamsulosin showed few side effects, and the drug was well tolerated in the study, Dr. Das reported.

He suggested that future trials needed to investigate high levels of obstruction in women with AUA SI scores over 23 and treatment with the combination of tamsulosin and antimuscarinic drugs, and added that the BFLQ, which has now been standardized, may be more appropriate for such studies.

Dr. Das is a consultant/adviser to Boehringer Ingelheim, Yamanouchi/Astellas, GlaxoSmithKline, and Lilly. The other co-authors are full-time employees of Boehringer