Products
Trospium chloride is commercially available in the form of dragées (Spasmo-Urgenin Neo, Spasmex). It has been approved in many countries since 1983.
Structure and properties
Trospium chloride (C25H30ClNO3, Mr = 428.0 g/mol) is a quaternary amine that exists as a chloride salt. It is a fine, colorless to slightly yellow, crystalline substance. Trospium chloride has structural similarities to atropine and is derived from nortropanolol. It is hydrophilic due to its positive charge and therefore is unlikely to cross the blood–brain barrier into the brain and has a low potential for central adverse effects. On the other hand, the disadvantage of hydrophilicity is low absorption.
Effects
Trospium chloride (ATC A03AB20, ATC G04BD09) has parasympatholytic properties. It is a competitive inhibitor of muscarinic receptors on bladder wall muscles, which play an important role in urinary excretion and the pathogenesis of irritable bladder.
Indications
For the treatment of hyperactive bladder (detrusor hyperactivity).
Dosage
According to the drug label. Unlike newer parasympatholytics for irritable bladder, trospium chloride must be taken twice daily because there are no sustained-release preparations on the market in many countries. It should be taken before a meal on an empty stomach because food ingested at the same time has a negative effect on bioavailability.
Contraindications
- Hypersensitivity
- Urinary retention
- Narrow-angle glaucoma
- Tachyarrhythmia
- Myasthenia gravis
- Severe inflammatory bowel disease
- Toxic megacolon
- Renal failure requiring dialysis
Full precautions can be found in the drug label.
Interactions
Trospium chloride is poorly metabolized via CYP3A4 and has a low potential for pharmacokinetic interactions. Other anticholinergics may potentiate adverse effects.
Adverse effects
Adverse effects can be attributed largely to the anticholinergic properties of the drug. The most common adverse effects include dry mouth, constipation, abdominal pain, and nausea.
