Side Effects of Vesicare (Solifenacin)
Vesicare (solifenacin) commonly causes dry mouth, constipation, and blurred vision as its primary side effects. The most frequently reported adverse effects of solifenacin include dry mouth (10.9% at 5mg and 27.6% at 10mg), constipation (5.4% at 5mg and 13.4% at 10mg), and blurred vision (3.8% at 5mg and 4.8% at 10mg) 1, 2.
Common Side Effects
Gastrointestinal Effects
- Dry mouth (10.9-27.6% depending on dose)
- Constipation (5.4-13.4%)
- Nausea (1.7-3.3%)
- Dyspepsia/indigestion (1.4-3.9%)
- Upper abdominal pain (1.9-1.2%)
- Vomiting (0.2-1.1%)
Ocular Effects
- Blurred vision (3.8-4.8%)
- Dry eyes (0.3-1.6%)
Urinary Effects
- Urinary tract infection (2.8-4.8%)
- Urinary retention (0-1.4%)
Neurological Effects
- Dizziness (1.9-1.8%)
- Headache
- Somnolence/drowsiness
Other Common Effects
- Fatigue (1.0-2.1%)
- Lower limb edema (0.3-1.1%)
- Depression (1.2% at 5mg)
- Cough (0.2-1.1%)
- Hypertension (1.4% at 5mg)
Serious Side Effects
Serious adverse effects are less common but may include:
- Serious allergic reactions (including angioedema with airway obstruction)
- Urinary retention
- Gastric retention
- Severe constipation (including fecal impaction, colonic obstruction, and intestinal obstruction)
- Central nervous system effects (confusion, hallucinations)
- QT prolongation (especially at higher doses)
Dose-Related Side Effects
The incidence and severity of side effects increase with higher doses. For example:
- Dry mouth occurs in 10.9% of patients taking 5mg but increases to 27.6% in those taking 10mg
- Constipation increases from 5.4% at 5mg to 13.4% at 10mg 1, 2
Discontinuation Due to Side Effects
The discontinuation rate due to adverse effects with solifenacin is 1.3% (relative risk compared to placebo), with an absolute risk difference of 0.01-0.03%. The most frequent adverse reaction leading to study discontinuation was dry mouth (1.5%) 1, 2.
Special Populations
Elderly Patients
Solifenacin 5mg/day is equally well tolerated in both younger (≤65 years) and older (>65 years) patients, with similar incidence and severity of dry mouth and other adverse events across age groups 3.
Patients with Comorbidities
- Not recommended in patients with clinically significant bladder outlet obstruction
- Contraindicated in patients with urinary retention
- Contraindicated in patients with gastric retention
- Use with caution in patients with decreased gastrointestinal motility
- Use with caution in patients being treated for narrow-angle glaucoma
- Not recommended in patients at high risk of QT prolongation 2
Monitoring and Management
- Monitor for signs of urinary retention, especially in patients with bladder outlet obstruction
- Watch for decreased gastrointestinal motility in susceptible patients
- Monitor for antimuscarinic CNS adverse reactions (confusion, hallucinations)
- Advise patients not to drive or operate heavy machinery until they know how solifenacin affects them
- Consider dose reduction or discontinuation if antimuscarinic side effects are troublesome 2
Long-Term Safety
In long-term studies, the incidence and severity of adverse reactions remained similar in patients who remained on the drug for up to 12 months compared to those who took it for 12 weeks 2, 4.
Solifenacin has been shown to have a more favorable side effect profile compared to some other antimuscarinic medications like oxybutynin immediate release, with fewer episodes and lower severity of dry mouth and a lower discontinuation rate 3.