Solifenacin

Like most anticholinergic agents, solifenacin has not been linked to liver enzyme elevations during therapy or to instances of clinically apparent liver injury with jaundice. In multiple prospective clinical trials of solifenacin in patients with overactive bladder syndrome, ALT elevations were reported in less than 1% of treated subjects, rates similar to that of placebo-recipients. Despite widespread clinical use for almost two decades, there has been only a single published case report of possible liver injury due to darifenacin use. An elderly woman with end stage liver injury developed transient elevations of serum aminotransferases and alkaline phosphatase without jaundice two weeks after starting solifenacin. Thus, liver injury due to solifenacin must be rare if it occurs at all.

Drug-Induced Liver Injury Severity and Toxicity (DILIst)

solifenacin

DILI Negative

Oral

DOI:10.1016/j.drudis.2019.09.022

G04BD08

G - Genito urinary system and sex hormones

QG - Genito urinary system and sex hormones

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 undergoes N-oxidation at the quinuclidin ring by cytochrome P450, though the exact enzymes are not revealed in the literature. The tetrahydroisoquinolone ring is 4R-hydroxylated by CYP3A4, CYP1A1, and CYP2D6. A 4R-hydroxy N-oxide metabolite is also formed by CYP3A4. Finally, solifenacin can undergo direct glucuronidation. Only solifenacin and the 4R-hydroxy metabolite are pharmacologically active.

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SOLIFENACIN

Established Pharmacologic Class [EPC] - Cholinergic Muscarinic Antagonist

Mechanisms of Action [MoA] - Cholinergic Muscarinic Antagonists

Solifenacin is a Cholinergic Muscarinic Antagonist. The mechanism of action of solifenacin is as a Cholinergic Muscarinic Antagonist.

Drugs that bind to but do not activate MUSCARINIC RECEPTORS, thereby blocking the actions of endogenous ACETYLCHOLINE or exogenous agonists. Muscarinic antagonists have widespread effects including actions on the iris and ciliary muscle of the eye, the heart and blood vessels, secretions of the respiratory tract, GI system, and salivary glands, GI motility, urinary bladder tone, and the central nervous system.

Drugs used in the treatment of urological conditions and diseases such as URINARY INCONTINENCE and URINARY TRACT INFECTIONS.

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 Tmax of solifenacin is 3-8 hours with a Css of 32.3ng/mL for a 5mg oral dose and 62.9ng/mL for a 10mg oral dose.

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 volume of distribution of solifenacin is 600L.

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