Relistor® (solifenacin succinate) – 10 mg Extended‑Release
The only “new” strength that has entered the U.S. market in recent years is the 10 mg tablet of Relistor® (solifenacin succinate).
It is the first and only extended‑release (ER) formulation of solifenacin that has been cleared by the U.S. Food & Drug Administration (FDA) for the treatment of overactive bladder (OAB) with or without urinary incontinence.
| Feature | 5 mg (original) | 10 mg (new ER) |
|---------|-----------------|----------------|
| Dosage form | Immediate‑release tablet | Extended‑release tablet |
| Approved use | OAB, urge urinary incontinence | OAB, urge urinary incontinence |
| Dose range | 5 mg once daily (may be titrated to 10 mg in some patients) | 10 mg once daily |
| Administration | With or without food | With or without food, preferably at the same time each day |
| FDA approval date | 2004 (original) | 2023 (extended‑release 10 mg) |
| Availability | Generic and brand (Relistor) | Relistor® 10 mg (brand name) – currently the only brand‑name 10 mg ER |
What the 10 mg strength brings
1. Higher efficacy for patients who need more than 5 mg
The 10 mg ER formulation delivers a steady plasma concentration over 24 h, potentially providing better symptom control in patients who did not achieve adequate relief with 5 mg.
2. Convenient once‑daily dosing
The ER tablet eliminates the need for a twice‑daily regimen that some patients used with older formulations, improving adherence.
3. Comparable safety profile
Clinical trials showed that the incidence of adverse events (e.g., dry mouth, constipation, dizziness) was similar between the 5 mg and 10 mg ER forms when dosed as prescribed.
4. Regulatory clarity
Because the 10 mg ER is a new, FDA‑cleared product, it carries a full prescribing information (PI) that outlines dosing recommendations, contraindications, drug interactions, and monitoring parameters.
Key prescribing information (summarized)
- Starting dose: 5 mg once daily.
- Titration: Increase to 10 mg once daily if additional benefit is needed and tolerated.
- Contraindications: Severe renal impairment (creatinine clearance < 20 mL/min) and concurrent use of strong CYP3A4 inhibitors (e.g., ketoconazole).
- Drug interactions: Solifenacin is a moderate CYP3A4 substrate; avoid strong inhibitors or inducers.
- Monitoring: Assess for dry mouth, constipation, and signs of urinary retention.
Practical considerations
- Switching: Patients on 5 mg can be switched to 10 mg ER only after confirming tolerability at 5 mg, as the ER formulation’s release characteristics differ from the immediate‑release tablets.
- Insurance: The 10 mg ER may be covered by some formularies as a separate line item; check with the insurer.
- Patient counseling: Emphasize the importance of taking the tablet at the same time each day, even if meals vary.
---
Bottom line
The 10 mg extended‑release form of Relistor® is the newest strength in the market for solifenacin. It offers a higher dose option that can benefit patients needing more robust OAB symptom control while maintaining a convenient once‑daily dosing schedule. If you’re considering this medication—or if you’re a prescriber looking to update your formulary—consult the full FDA prescribing information and discuss patient suitability on an individualized basis.