Amiodarone
Severe
Database
Drug interaction classified as: synergy
Source: DDInter
Drug reference
Solifenacin
Muscarinic acetylcholine receptor antagonist (anticholinergic) · Agent for Overactive Bladder; Urinary Antispasmodic
Also known as Solifenacin succinate, Vesicare, Vesikare
START
Assess for urinary retention risk (BPH, neurogenic bladder), gastric emptying disorders, narrow-angle glaucoma risk. Check post-void residual if BPH suspected. Start 5mg daily.
TYPICAL MAX
10mg/day. Anticholinergic side effects are dose-limiting. In renal impairment (CrCl <30), max 5mg/day.
STOP IF
Urinary retention, acute angle-closure glaucoma symptoms (eye pain, blurred vision, halos), severe constipation/ileus, anaphylaxis, angioedema.
WATCH
Post-void residual in men with BPH (retention risk). Cognitive effects in elderly—anticholinergic burden may worsen dementia. Constipation is common—advise fiber and hydration. Dry mouth can be severe. CYP3A4 inhibitors increase levels.
CDSCO approvedATC G04BD08
KDIGO 2024 + manufacturer label
- ONSET
- 30min · Onset ~30 min
- PEAK
- 5.5h · Tmax 3-8 hours
- t½
- 2.3d · t½ ~45-68 hours
- DURATION
- 1d · 24 hours (QD)
EXCRETION
Renal as metabolites (~69%)
route + CYP
INTERACTIONS
12 major
SEVERE in our sources
PREGNANCY
Limited data; use only if clearly needed. Animal studies show no teratogenicity at therapeutic doses.
FDA category + note
Top interactionssee all 12 →
- AmiodaroneSevereDatabaseDDInter
- AmisulprideSevereDatabaseDDInter
- AmprenavirSevereDatabaseDDInter
- AnagrelideSevereDatabaseDDInter
Available in India
52 branded formulations and 19 fixed-dose combinations. Look up specific brands in the Drugs workspace.
Mechanism
Competitive antagonist of M3 muscarinic receptors in bladder detrusor muscle, inhibiting involuntary detrusor contractions and increasing bladder capacity. Selective for M3 over M2 receptors (M3:M2 ratio ~3:1). Minimal CNS penetration.
Indications
Overactive bladder (OAB) with symptoms of urge urinary incontinence, urgency, and frequency
Dosing
- Adult
- 5mg PO daily initially; may increase to 10mg daily after 4 weeks if tolerated and response inadequate. Take with or without food.
- Pediatric
- Not established in children.
- Renal adjustment
- CrCl ≥30: no adjustment. CrCl <30: max 5mg/day.
- Hepatic adjustment
- Mild (Child-Pugh A): no adjustment. Moderate (Child-Pugh B): max 5mg/day. Severe (Child-Pugh C): contraindicated.
- Geriatric
- Start 5mg daily; increased anticholinergic side effects; monitor for cognitive impairment and constipation.
- Max dose
- 10mg/day
Pharmacokinetics
Onset
OAB symptom improvement within 1-2 weeks; maximal benefit 4-8 weeks
Peak effect
Tmax 3-8 hours; steady-state in ~10 days
Duration
24 hours (QD dosing)
Half-life
~45-68 hours (long half-life allows QD dosing; accumulation over 1-2 weeks)
Bioavailability
~90% (not affected by food)
Protein binding
~98% (albumin, alpha-1-acid glycoprotein)
Metabolism
Extensive hepatic via CYP3A4 to inactive metabolites; some via glucuronidation
Excretion
~69% renal (metabolites); ~23% fecal
Contraindications
- Urinary retention
- Gastric retention
- Uncontrolled narrow-angle glaucoma
- Severe hepatic impairment (Child-Pugh C)
- Hypersensitivity to solifenacin
Side effects
Common
Dry mouthConstipationBlurred visionUrinary retentionDyspepsiaNasopharyngitisUpper respiratory infection
Serious
- Urinary retention requiring catheterization
- Acute narrow-angle glaucoma
- Gastric retention / ileus
- Angioedema
- Anaphylaxis
- Cognitive impairment / confusion (elderly)
Pregnancy & lactation
Pregnancy
Limited data; use only if clearly needed. Animal studies show no teratogenicity at therapeutic doses.
Lactation
Excretion in breast milk unknown; use with caution during breastfeeding.
Drug interactions
Amisulpride
Severe
Database
Drug interaction classified as: synergy
Source: DDInter
Amprenavir
Severe
Database
Drug interaction classified as: metabolism
Source: DDInter
Anagrelide
Severe
Database
Drug interaction classified as: synergy
Source: DDInter
Arsenic Trioxide
Severe
Database
Drug interaction classified as: synergy
Source: DDInter
Atazanavir
Severe
Database
Drug interaction classified as: metabolism
Source: DDInter
Bedaquiline
Severe
Database
Drug interaction classified as: synergy
Source: DDInter
Bepridil
Severe
Database
Drug interaction classified as: synergy
Source: DDInter
Boceprevir
Severe
Database
Drug interaction classified as: metabolism
Source: DDInter
Cabozantinib
Severe
Database
Drug interaction classified as: synergy
Source: DDInter
Ceritinib
Severe
Database
Drug interaction classified as: metabolism
Source: DDInter
Chloroquine
Severe
Database
Drug interaction classified as: synergy
Source: DDInter
Related guidelines
Ask House about Solifenacin
Continue into a citation-backed clinical answer with the drug context already attached.
Sources: Goodman & Gilman 14e, Katzung, BNF·Verified: 2026-05-19 · House clinical team·Cockpit curated: 2026-05-19