Trospium

Trospium is a prescription antimuscarinic agent used to treat overactive bladder, particularly symptoms such as urge urinary incontinence, urinary urgency, and frequency. It is available as trospium chloride in immediate-release and extended-release formulations.

Pharmacology and mechanism of action: Trospium is a quaternary ammonium compound that acts as a competitive antagonist of muscarinic acetylcholine receptors. It preferentially blocks peripheral M3 receptors in the detrusor muscle, reducing involuntary bladder contractions and helping to alleviate overactive bladder symptoms. Because of its charged structure, trospium penetrates the central nervous system poorly, which lowers the risk of central anticholinergic effects such as cognitive changes compared with some other antimuscarinics.

Pharmacokinetics: Trospium is taken orally and is predominantly excreted unchanged in the urine, with metabolism playing a minor role. Its limited central nervous system exposure contributes to a more favorable CNS safety profile in many patients, though peripheral anticholinergic effects remain common.

Forms and dosing considerations: Trospium is available in immediate-release and extended-release forms. Dosing regimens vary by formulation, renal function, and tolerability, and clinicians tailor therapy accordingly. The medication is generally dosed with meals to optimize tolerability and absorption.

Contraindications and precautions: Trospium is contraindicated in patients with urinary retention, gastric retention, or uncontrolled narrow-angle glaucoma. It should be used with caution in the elderly and in patients with severe renal impairment, given predominant renal excretion. As with other anticholinergics, trospium can cause dry mouth, constipation, blurred vision, and other anticholinergic effects; concomitant use with other anticholinergic agents can increase these risks.