What is/are Solifenacin?
Solifenacin (INN, trade name Vesicare) is a urinary antispasmodic of the antimuscarinic class. It is used in the treatment of overactive bladder with or without urge incontinence. It is manufactured and marketed by Astellas.
Solifenacin is metabolized in the liver by the cytochrome P450 enzyme CYP3A4. When administered concomitantly with drugs that inhibit CYP3A4, such as ketoconazole, the metabolism of solifenacin is impaired, leading to an increase in its concentration in the body and a reduction in its excretion. The manufacturer recommends that the dosage of solifenacin not exceed 5 mg a day if it is taken with a potent CYP3A4 inhibitor.
As stated above, solifenacin may also prolong the QT interval. Therefore, it should not be administered concomitantly with drugs which also have this effect, such as moxifloxacin or pimozide.
The most common side effects of solifenacin are dry mouth, blurred vision, and constipation. As all anticholinergics, solifenacin may rarely cause heat prostration due to decreased perspiration
Mechanism of action
Solifenacin is a competitive cholinergic receptor antagonist. The binding of acetylcholine to these receptors, particularly the M3 receptor subtype, plays a critical role in the contraction of smooth muscle. By preventing the binding of acetylcholine to these receptors, solifenacin reduces smooth muscle tone in the bladder, allowing the bladder to retain larger volumes of urine and reducing the number of micturition, urgency and incontinence episodes. Because of a long elimination half life, a once-a-day dose can offer 24 hour control of the urinary bladder smooth muscle tone.
This article uses material from the Wikipedia article Solifenacin, which is released under the Creative Commons Attribution-Share-Alike License 3.0.