Optimal Timing for Solifenacin Administration
Solifenacin can be taken at any time of day, with or without food, as its pharmacokinetics are not affected by food intake or timing of administration. 1, 2
Dosing Flexibility
Once-daily administration is appropriate regardless of meal timing, as clinical pharmacokinetic studies demonstrate that food ingestion does not significantly affect solifenacin's absorption, with geometric mean ratios for Cmax (1.033), AUClast (1.068), and AUC0-inf (1.040) all falling within the predefined no-food-effect boundaries of 0.8-1.25. 2
The drug achieves peak plasma concentrations 3-8 hours after oral administration, with an absolute bioavailability of approximately 90% that remains unchanged with concomitant food intake. 1
The terminal elimination half-life ranges from 33 to 85 hours, which supports once-daily dosing at any time that is convenient for the patient. 1
Practical Administration Recommendations
Patients should select a consistent time each day that fits their routine to optimize adherence, as the long half-life provides 24-hour symptom control regardless of when the dose is taken. 3, 4
Standard dosing begins at 5 mg once daily, with the option to increase to 10 mg once daily based on symptom severity and tolerability. 3, 4, 5
Full therapeutic effects occur after 2-4 weeks of treatment, though improvements may be observed as early as week 2. 1, 4
Special Population Considerations
For patients with moderate hepatic impairment (Child-Pugh score 7-9) or severe renal impairment (creatinine clearance <30 mL/min), doses should not exceed 5 mg daily. 1
Patients taking potent CYP3A4 inhibitors (such as ketoconazole) should also be limited to a maximum dose of 5 mg daily, as exposure to solifenacin increases approximately 2-fold with these medications. 1