Adult: For the symptomatic treatment of urge urinary incontinence, urinary frequency and urgency: As conventional tab: 20 mg bid. As extended-release cap: 60 mg once daily in the morning. Reassess the need for continued therapy at regular intervals of 3-6 months. Elderly: ≥75 years As conventional tab: 20 mg once daily based on patient tolerability.
Renal Impairment
CrCl (mL/min)
Dosage
<30
As conventional tab: 20 mg once daily or 20 mg on alternate days. As extended-release cap: Not recommended.
Hepatic Impairment
Severe: Contraindicated.
Administration
Should be taken on an empty stomach. Take 1 hr before meals or on an empty stomach.
Contraindications
Existing or predisposition to urinary retention, gastric retention, severe gastrointestinal conditions (e.g. toxic megacolon), uncontrolled angle-closure glaucoma, myasthenia gravis, tachyarrhythmia. Severe hepatic impairment.
Special Precautions
Patient with bladder outflow obstruction, gastrointestinal obstructive disorders (e.g. pyloric stenosis), intestinal atony, ulcerative colitis, autonomic neuropathy, controlled/treated angle-closure glaucoma, hiatus hernia associated with reflux oesophagitis, conditions wherein fast heart rates are undesirable (e.g. CHF, coronary artery disease, hyperthyroidism); Alzheimer's disease. Extended-release cap: Not recommended for use in severe renal impairment. Renal and mild to moderate hepatic impairment. Elderly. Pregnancy and lactation.
Adverse Reactions
Significant: Decreased gastrointestinal motility; increased risk of urinary or gastric retention; CNS effects (e.g. drowsiness, dizziness, blurred vision, confusion, hallucinations). Cardiac disorders: Tachycardia. Eye disorders: Dry eyes. Gastrointestinal disorders: Constipation, dyspepsia, dry mouth, nausea, abdominal pain, abdominal distention, flatulence, dysgeusia. General disorders and administration site conditions: Fatigue. Musculoskeletal and connective tissue disorders: Back pain. Nervous system disorders: Headache. Renal and urinary disorders: UTI. Respiratory, thoracic and mediastinal disorders: Nasal dryness. Skin and subcutaneous tissue disorders: Dry skin. Potentially Fatal: Angioedema of face, lips, tongue or larynx.
This drug may cause dizziness, drowsiness, confusion, hallucinations, and/or blurred vision; if affected, do not drive or operate machinery.
Monitoring Parameters
Check the voiding patterns at baseline and periodically during treatment. Monitor renal function, postvoid residual (PVR) urine volume and UTI prior to therapy initiation; anticholinergic effects (e.g. dry mouth, constipation, dizziness).
Overdosage
Symptoms: Dry mouth, tachycardia, and micturition disorders. Management: Supportive and symptomatic treatment. Perform gastric lavage and administer activated charcoal. May administer local pilocarpine in patients with glaucoma. Catheterisation may be considered in patients with urinary retention. In severe cases, a parasympathomimetic agent (e.g. neostigmine) may be given. Administer β-blockers (e.g. 1 mg IV propranolol) and monitor ECG and blood pressure in case of insufficient response, pronounced circulatory instability and/or tachycardia.
Drug Interactions
Other agents that are eliminated by active tubular secretion (e.g. procainamide, pancuronium, vancomycin, morphine, tenofovir) may increase the serum concentration of trospium chloride and/or the coadministered drug. May decrease the exposure and peak serum levels with metformin immediate-release tab. May potentiate the effects of agents with anticholinergic action (e.g. amantadine, TCAs). May enhance the tachycardic effect of β-sympathomimetics. May decrease the efficacy of prokinetic agents (e.g. metoclopramide).
Food Interaction
Reduced absorption and bioavailability when taken with food, particularly high-fat meals. May cause additive sedative effects (e.g. drowsiness) with alcohol.
Action
Description: Trospium chloride is a quaternary ammonium antimuscarinic agent which antagonises the effects of acetylcholine at muscarinic receptors located in the cholinergically innervated organs. It also reduces the contractile tone of smooth muscles in the urinary bladder. Pharmacokinetics: Absorption: Incompletely absorbed from the gastrointestinal tract. Reduced absorption and bioavailability with food, particularly high-fat meals. Bioavailability: Conventional tab: Approx 10% (range: 4-16%). Time to peak plasma concentration: 4-6 hours. Distribution: Volume of distribution: 395->600 L. Plasma protein binding: 48-85%. Metabolism: Hypothesised to be metabolised via ester hydrolysis with subsequent conjugation of benzylic acid to form azoniaspironortropanol with glucuronic acid. Excretion: Mainly via faeces (85%); urine (approx 6%; approx 60% as unchanged drug and approx 10% as the spiroalcohol metabolite). Elimination half-life: 10-20 hours (conventional tab); approx 35 hours (extended-release cap). Primarily eliminated via active tubular secretion.
Chemical Structure
Trospium chloride Source: National Center for Biotechnology Information. PubChem Compound Summary for CID 5284631, Trospium chloride. https://pubchem.ncbi.nlm.nih.gov/compound/Trospium-chloride. Accessed Jan. 26, 2021.