Solif Tablet

Solifenacin is a competitive muscarinic receptor antagonist indicated to treat an overactive bladder with urinary incontinence, urgency, and frequency. It has a long duration of action as it is usually taken once daily.

Solifenacin was granted FDA approval on 19 November 2004.

Solifenacin is a muscarinic antagonist with antispasmodic properties used to treat urge urinary incontinence, urgency, and urinary frequency associated with an overactive bladder.

Solifenacin tablets are indicated to treat an overactive bladder with urinary incontinence, urgency, and frequency.

• Benign Prostatic Hyperplasia (BPH)
• Urinary Bladder
• Overactive

Solifenacin antagonizes the M2 and M3 muscarinic receptors in the bladder to treat an overactive bladder. It has a long duration of action as it is usually taken once daily. Patients taking solifenacin should be aware of the risks of angioedema and anaphylaxis.

Solifenacin is a competitive muscarinic receptor antagonist. It has the highest affinity for M3, M1, and M2 muscarinic receptors. 80% of the muscarinic receptors in the bladder are M2, while 20% are M3. Solifenacin's antagonism of the M3 receptor prevents contraction of the detrusor muscle, while antagonism of the M2 receptor may prevent contraction of smooth muscle in the bladder.

Solifenacin is well absorbed in the duodenum, jejunum, and ileum but not the stomach. Absorption occurs via passive diffusion and so no transporters are involved. The mean oral bioavailability of solifenacin is 88%. The T_max of solifenacin is 3-8 hours with a C_ss of 32.3ng/mL for a 5mg oral dose and 62.9ng/mL for a 10mg oral dose.

The volume of distribution of solifenacin is 600L.

Solifenacin is 93-96% protein bound in plasma, mainly to alpha-1-acid glycoprotein.

69.2±7.8% of a radiolabelled dose is recovered in the urine, 22.5±3.3% was recovered in feces, and 0.4±7.8% was recovered in exhaled air. 18% of solifenacin is eliminated as the N-oxide metabolite, 9% is eliminated as the 4R-hydroxy N-oxide metabolite, and 8% is eliminated as the 4R-hydroxy metabolite.

The elimination half life of solifenacin ranges from 33-85 hours.

The clearance of solifenacin is 7-14L/h and a renal clearance of 0.67-1.51L/h.

The LD₅₀ of Solifenacin has yet to be determined.

Signs of overdose include severe anticholinergic effects, mental status changes, and decreased consciousness. In case of overdose, treat patients with gastric lavage and supportive measures. Monitor patients with an ECG.

• Take with or without food.