San Diego-Treatment with the dual neurotransmitter reuptake inhibitor duloxetine (Yentreve) results in durable improvement in symptoms of stress urinary incontinence, according to a study of open-label transition from placebo to active therapy.
The open-label phase of the study demonstrated that patients who transitioned from placebo to duloxetine achieved rates of im-provement similar to those attained by patients who received duloxetine during 12 weeks of double-blind therapy. The study also showed that patients initially treated with duloxetine maintained their improvement throughout open-label therapy.
"We knew that duloxetine improved symptoms of stress urinary incontinence, but now we know that the results are durable, which is an important finding for a chronic condition that requires ongoing treatment," co-author David Muram, MD, said at the American Urogynecologic Society/Society of Gynecologic Surgeons meeting here.
Significantly improved symptoms The findings came from the open-label continuation of a trial that originally began as a placebo-controlled trial of duloxetine in women with stress incontinence. During the randomized phase of the study, 12 weeks of treatment with duloxetine significantly improved incontinence symptoms compared with placebo (J Urol 2003; 170:1259-63; Br J Obstet Gynaecol 2004; 111:249-57; Br J Urol Int 2004; 93:311-8).
The randomized phase involved 344 patients who initially received duloxetine, 40 mg twice daily, and 339 patients originally assigned to placebo. At baseline, the women averaged 18 to 19 incontinence episodes weekly, and about 60% reported moderate or severe stress urinary incontinence. Subsequently, 215 duloxetine pa-tients and 278 placebo patients entered the open-label phase of the study, reported Dr. Muram, a medical adviser for Eli Lilly & Co., Indianapolis.
After 4 weeks of randomized treatment, 68.6% of duloxetine patients said their condition had improved, compared with 43.5% of placebo patients (p<.001). The significant difference was maintained throughout the 12-week double-blind phase.
Within 4 weeks after the transition from placebo to duloxetine, 67% of the former placebo patients reported improvement. After 12 weeks of open-label treatment, 80% of patients initially treated with duloxetine and 77.5% initially treated with placebo reported improvement in stress incontinence symptoms, including fewer episodes of incontinence.
"It was exciting to see that those patients who transitioned from placebo to duloxetine did just as well as those who were on duloxetine during the randomized study," Dr. Muram said. "However, it was especially gratifying to see that the improvement patients attained with duloxetine during the randomized study was maintained during this open-label extension. The results show that duloxetine's effects are long lasting."