1. Introduction
Solifenacin is a urinary antispasmodic and anticholinergic agent used to manage overactive bladder (OAB) symptoms such as urinary urgency, frequency, and incontinence. It works by inhibiting muscarinic receptors in the bladder, reducing involuntary bladder contractions and improving bladder control.
2. Indications
- Overactive Bladder (OAB):
- Treatment of urinary frequency, urgency, and urge incontinence.
3. Dosage
Adults:
- Standard dose: 5 mg orally once daily.
- Maximum dose: 10 mg orally once daily if tolerated.
Elderly:
- Same as adult dosing, but use with caution due to increased sensitivity to anticholinergic effects.
Children:
- Not recommended; safety and efficacy have not been established in patients under 18 years of age.
Renal Impairment:
- Moderate impairment (eGFR 30–50 mL/min): Maximum dose of 5 mg once daily.
- Severe impairment (eGFR <30 mL/min): Not recommended.
Hepatic Impairment:
- Moderate impairment (Child-Pugh class B): Maximum dose of 5 mg once daily.
- Severe impairment (Child-Pugh class C): Contraindicated.
4. Administration
- Take orally, once daily, with or without food.
- Swallow tablets whole; do not crush or chew.
5. Forms Available
- Tablets: 5 mg, 10 mg
6. Side Effects
6.1 Common Side Effects:
- Dry mouth
- Constipation
- Blurred vision
- Dizziness
- Fatigue
6.2 Less Common Side Effects:
- Urinary retention
- Dyspepsia
- Nausea
6.3 Rare but Serious Side Effects:
- Severe allergic reactions (e.g., angioedema)
- QT prolongation (heart rhythm changes)
- Heat stroke (due to reduced sweating)
7. Warnings
- Urinary Retention: Avoid use in patients with a history of urinary retention or bladder outflow obstruction.
- Narrow-Angle Glaucoma: Contraindicated in patients with uncontrolled narrow-angle glaucoma.
- QT Prolongation: Use cautiously in patients with a history of QT prolongation or those on QT-prolonging drugs.
- Gastrointestinal Disorders: Avoid use in patients with severe gastrointestinal motility disorders such as paralytic ileus.
8. Precautions
- Use cautiously in elderly patients due to an increased risk of anticholinergic side effects such as confusion, drowsiness, or falls.
- Patients with myasthenia gravis or autonomic neuropathy may experience worsening symptoms.
- Avoid dehydration or overheating, as solifenacin may reduce sweating and increase the risk of heat stroke.
9. Interactions
- CYP3A4 inhibitors (e.g., ketoconazole, erythromycin): May increase solifenacin levels; limit dose to 5 mg daily.
- QT-prolonging medications (e.g., amiodarone, sotalol): Increased risk of arrhythmias.
- Other anticholinergics (e.g., oxybutynin, tolterodine): Enhanced anticholinergic side effects.
- Prokinetic agents (e.g., metoclopramide): Reduced efficacy of prokinetic drugs.
10. Monitoring Parameters
- Assess symptom improvement in urinary frequency, urgency, and incontinence.
- Monitor for anticholinergic side effects, including dry mouth, constipation, and blurred vision.
- ECG monitoring may be needed in patients at risk of QT prolongation.
11. Use in Children
- Not recommended; safety and efficacy in paediatric populations have not been established.
12. Use in Pregnancy
- Category C: Use only if the potential benefit justifies the risk to the foetus, as there is limited data on use during pregnancy.
13. Use in Elderly
- Safe for use but monitor closely for side effects such as confusion, drowsiness, and falls due to increased sensitivity to anticholinergics.
14. Use in Kidney Disease
- Dose adjustment is required in moderate renal impairment.
- Avoid use in severe renal impairment.
15. Use in Liver Disease
- Dose adjustment is required in moderate hepatic impairment.
- Contraindicated in severe hepatic impairment.
16. Patient Counselling Points
- Take solifenacin once daily as prescribed, with or without food.
- Inform your doctor if you experience difficulty urinating, severe constipation, or confusion.
- Avoid driving or operating machinery if you experience dizziness or blurred vision.
- Stay hydrated and avoid overheating, as solifenacin may reduce sweating.
- Do not stop taking solifenacin without consulting your doctor, as symptoms may worsen.
17. Table of Brand Names, Manufacturer, and Prices in USD
Brand Name | Manufacturer | Strength/Dosage Form | Price (USD) |
---|---|---|---|
Vesicare | Astellas Pharma | 5 mg Tablet | $350 (30 tablets) |
Generic Solifenacin | Various | 5 mg Tablet | $150 (30 tablets) |
18. 15 FAQs (Frequently Asked Questions)
1. What is Solifenacin used for?
Solifenacin is used to treat overactive bladder symptoms such as urgency, frequency, and urge incontinence.
2. How does Solifenacin work?
It blocks muscarinic receptors in the bladder, reducing involuntary contractions and improving bladder control.
3. Can Solifenacin cause dry mouth?
Yes, dry mouth is one of the most common side effects.
4. Can Solifenacin be used in children?
No, it is not recommended for use in patients under 18 years.
5. How should Solifenacin be taken?
Take it orally, once daily, with or without food.
6. Can Solifenacin cause constipation?
Yes, constipation is a common side effect.
7. Is Solifenacin safe during pregnancy?
It should only be used during pregnancy if the benefits outweigh the risks.
8. Can Solifenacin cause blurred vision?
Yes, blurred vision is a possible side effect due to its anticholinergic action.
9. How long does Solifenacin take to work?
Improvement in symptoms may be noticed within a few days, but full effects may take weeks.
10. Can Solifenacin interact with other medications?
Yes, it interacts with CYP3A4 inhibitors, QT-prolonging drugs, and other anticholinergics.
11. Is Solifenacin safe for elderly patients?
Yes, but they should be monitored closely for anticholinergic side effects like confusion or dizziness.
12. Can Solifenacin cause urinary retention?
Yes, it can cause urinary retention in some patients, especially those with bladder outflow obstruction.
13. Can alcohol be consumed while taking Solifenacin?
Alcohol may enhance side effects like drowsiness or dizziness; use cautiously.
14. Can Solifenacin be used in severe kidney disease?
No, it is not recommended in severe renal impairment.
15. How should Solifenacin be stored?
Store at room temperature, away from moisture and heat.