Solifenacin for treating overactive bladder

This study evaluated the effectiveness and safety of solifenacin (Vesicare) for treating overactive bladder (OAB). The authors concluded that the 5 mg dose of solifenacin was similar to tolterodine, while balancing effectiveness and side effects.

Oral anti-muscarinic agents are the typical first-line drug therapy for overactive bladder (OAB). This type of treatment relaxes the muscle of the bladder to prevent it from having spasms. This helps reduce incontinence  (leaking urine) and urges to urinate right away. Solifenacin is a part of a new generation of anti-muscarinic agents that have been shown to improve OAB symptoms. However, the long-term outcomes of solifenacin treatment and the tolerability of its side effects remain uncertain.

This study analyzed a total of ten other studies, including 6,067 patients. Studies compared different doses of solifenacin to placebo (substance with no active effect) or tolterodine (Detrol). These studies lasted from 8 to 121 weeks.

Compared to placebo, solifenacin-treated patients had fewer episodes of urgency (– 1.08), voids (– 1.07), and incontinence (– 0.51) per 24 hours. Solifenacin-treated patients also had fewer nighttime voids (– 0.14), and smaller urine volumes per void (28.78 milliliters) per 24 hours.

Compared to tolterodine, solifenacin-treated patients had fewer episodes of urgency (– 0.37), voids (– 0.06), and incontinence (– 0.48) per 24 hours. Solifenacin-treated patients also had fewer nighttime voids (– 0.07), and smaller urine volumes per void (10.86 milliliters) per 24 hours.

10 mg of solifenacin led to significantly fewer voids (0.29) and larger urine volumes per void (– 10.41) per 24 hours compared to a 5 mg dose. 

Dry mouth, constipation, and blurred vision were the most commonly reported side effects associated with solifenacin. Solifenacin increased risk of constipation 2.91-fold and the risk of blurred vision 3.19-fold compared to tolterodine. 10 mg of solifenacin increased the risk of dry mouth compared to 5 mg. The risks of constipation and blurred vision were not significantly different between the doses.

The authors concluded that solifenacin was similar to tolterodine in terms of effectiveness and side effects. The 5 mg dose of solifenacin balanced effectiveness and tolerability compared to the 10 mg dose.

The majority of the studies analyzed here were short-term (average 12 weeks). This makes it difficult to properly evaluate long-term side effects. Also, nearly all of the studies collected effectiveness data from self-reported bladder diaries. This limits the conclusions that may be drawn from the results. Larger studies are needed to further confirm the safety and effectiveness of solifenacin for OAB.