Solifenacin Succinate Drug Information

Solifenacin succinate tablets are indicated for the treatment of adults with overactive bladder with symptoms of urge urinary incontinence, urgency, and urinary frequency.

Dosing Information

The recommended oral dose of solifenacin succinate tablets is 5 mg once daily. If the 5 mg dose is well tolerated, the dose may be increased to 10 mg once daily. Solifenacin succinate tablets should be taken with water and swallowed whole.

Solifenacin succinate tablets can be administered with or without food.

Dosing Recommendations in Patients with Renal Impairment

Do not exceed 5 mg once daily in patients with severe renal impairment (CL cr <30 mL/min/1.73 m 2 ).

Dosing Recommendations in Patients with Hepatic Impairment

Do not exceed 5 mg once daily in patients with moderate hepatic impairment (Child-Pugh B). Do not use of solifenacin succinate tablets in patients with severe hepatic impairment (Child-Pugh C).

Dosing Recommendations in Patients Taking CYP3A4 Inhibitors

Do not exceed 5 mg once daily when solifenacin succinate tablets are administered with strong CYP3A4 inhibitors such as ketoconazole.

Clinical Trials Experience

Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in practice. Solifenacin succinate has been evaluated for safety in 1811 adult patients in four randomized, placebo-controlled trials (Studies 1 to 4). Expected adverse reactions of antimuscarinic agents are dry mouth, constipation, blurred vision (accommodation abnormalities), urinary retention, and dry eyes.

The incidence of dry mouth and constipation in patients treated with solifenacin succinate was higher in the 10 mg dose group compared to the 5 mg dose group. In the four 12-week double-blind clinical trials, severe fecal impaction, colonic obstruction, and intestinal obstruction were reported in one patient each, all in the solifenacin succinate 10 mg group. Angioneurotic edema was reported in one patient taking solifenacin succinate 5 mg.

Compared to 12 weeks of treatment with solifenacin succinate, the incidence and severity of adverse reactions were similar in patients who remained on drug for up to 12 months in Study 5. The most frequent adverse reaction leading to study discontinuation was dry mouth (1.5%). Table 1 lists the rates of identified adverse reactions, in the four randomized, placebo-controlled trials at an incidence greater than placebo and in 1% or more of patients treated with solifenacin succinate 5 or 10 mg once daily for up to 12 weeks.

Table 1: Adverse Reactions Reported by ≥ 1% of Patients and Exceeding Placebo in Studies Postmarketing Experience The following adverse reactions have been identified during post-approval use of solifenacin succinate in the U.S. and/or outside of the U.S. Because these reactions are reported voluntarily from a population of uncertain size, it is not always possible to reliably estimate their frequency or establish a causal relationship to drug exposure. General disorders and administration site conditions: peripheral edema, hypersensitivity reactions (including angioedema with airway obstruction, rash, pruritus, urticaria, anaphylactic reaction); Nervous system disorders: dizziness, headache, confusion, hallucinations, delirium, somnolence; Cardiac disorders: QT prolongation, Torsade de Pointes, atrial fibrillation, tachycardia, palpitations; Hepatobiliary disorders: liver disorders mostly characterized by abnormal liver function tests, AST (aspartate aminotransferase), ALT (alanine aminotransferase), GGT (gamma-glutamyl transferase); Renal and urinary disorders: renal impairment, urinary retention; Metabolism and nutrition disorders: decreased appetite, hyperkalemia; Skin and subcutaneous tissue disorders: exfoliative dermatitis, erythema multiforme, dry skin; Eye disorders: glaucoma; Gastrointestinal disorders: gastroesophageal reflux disease, ileus, vomiting, abdominal pain, dysgeusia, sialadenitis; Respiratory, thoracic and mediastinal disorders: dysphonia, nasal dryness; Musculoskeletal and connective tissue disorders: muscular weakness.

Strong CYP3A4 Inhibitors Solifenacin is a substrate of CYP3A4. Concomitant use of ketoconazole, a strong CYP3A4 inhibitor, significantly increased the exposure of solifenacin. The dosage of solifenacin succinate greater than 5 mg once daily is not recommended when concomitantly used with strong CYP3A4 inhibitors.

Pregnancy Risk Summary There are no studies with the use of solifenacin succinate in pregnant women to inform a drug-associated risk of major birth defects, miscarriages, or adverse maternal or fetal outcomes. No adverse developmental outcomes were observed in animal reproduction studies with oral administration of solifenacin succinate to pregnant mice during the period of organogenesis at a dose resulting in 1.2 times the systemic exposure at the maximum recommended human dose (MRHD) of 10 mg/day. However, administration of doses 3.6 times and greater than the MRHD during organogenesis produced maternal toxicity in the pregnant mice and resulted in developmental toxicity and reduced fetal body weights in offspring.

In the U.S. general population, the estimated background risk of major birth defects or miscarriage in clinically recognized pregnancies is respectively. Data Animal Data Oral administration of 14 C-solifenacin succinate to pregnant mice resulted in the recovery of radiolabel in the fetus indicating that solifenacin-related product can cross the placental barrier. In pregnant mice, administration of solifenacin succinate at a dose of 250 mg/kg/day (7.9 times the systemic exposure at the MRHD of 10 mg), resulted in an increased incidence of cleft palate and increased maternal lethality.

Administration of solifenacin succinate to pregnant mice during organogenesis at greater than or equal to 3.6 times (100 mg/kg/day and greater) the systemic exposure at the MRHD, resulted in reduced fetal body weights and reduced maternal body weight gain. No embryo-fetal toxicity or teratogenicity was observed in fetuses from pregnant mice treated with solifenacin succinate at a dose of 30 mg/kg/day (1.2 times the systemic exposure at the MRHD). Administration of solifenacin succinate to pregnant rats and rabbits at a dose of 50 mg/kg/day (< 1 times and 1.8 times the systemic exposure at the MRHD, respectively), resulted in no findings of embryo-fetal toxicity.

Oral pre- and post-natal administration of solifenacin succinate at 100 mg/kg/day (3.6 times the systemic exposure at the MRHD) during the period of organogenesis through weaning, resulted in reduced peripartum and postnatal survival, reduced body weight gain by the pups, and delayed physical development (eye opening and vaginal patency). An increase in the percentage of male offspring was also observed in litters from offspring (F2 generation) exposed to maternal doses of 250 mg/kg/day. There were no effects on natural delivery in mice treated with 1.2 times (30 mg/kg/day) the expected systemic exposure at the MRHD.

• Solifenacin succinate tablets are contraindicated in patients:
• With urinary retention,
• With gastric retention,
• With uncontrolled narrow-angle glaucoma, and
• Who have demonstrated hypersensitivity to solifenacin succinate or the inactive ingredients in solifenacin succinate tablets. Reported adverse reactions have included anaphylaxis and angioedema.
• Urinary retention.
• Gastric retention.
• Uncontrolled narrow-angle glaucoma.
• Hypersensitivity to this product or any of its components.

Overdosage with solifenacin succinate can potentially result in severe antimuscarinic effects and should be treated accordingly. The highest dose ingested in an accidental overdose of solifenacin succinate was 280 mg (28 times the maximum dosage) in a 5-hour period. This case was associated with mental status changes.

Some cases reported a decrease in the level of consciousness. Intolerable antimuscarinic adverse reactions (fixed and dilated pupils, blurred vision, failure of heel-to-toe exam, tremors, and dry skin) occurred on day 3 in normal volunteers taking 50 mg daily (5 times the maximum recommended therapeutic dose) and resolved within 7 days following discontinuation of drug. In the event of overdose with solifenacin succinate, treat with gastric lavage and appropriate supportive measures.

ECG monitoring is also recommended.