[Durgical](https://durgical.com/en/) › [DurgiPedia](https://durgical.com/en/durgipedia/) › [Pharmacology](https://durgical.com/en/pharmacology/) › [Overactive bladder agents](https://durgical.com/en/pharmacology/classes/overactive-bladder-agents/) › Trospium # Trospium ## Overactive bladder agents? Overactive bladder agents A quaternary antimuscarinic for overactive bladder. It barely enters the brain and is cleared by the kidneys, so central side effects are less likely. Updated Nov 1, 2026 Also called: Trospium chloride ## Quick facts **Group** [Overactive bladder agents](https://durgical.com/en/pharmacology/classes/overactive-bladder-agents/) **Target** Muscarinic M3 (and M2) receptors of the bladder (antagonist) **Used for** Overactive bladder **Key effects** Dry mouth · Constipation · Headache **Monitor** Urinary retention · Bowel habit · Kidney function **ATC** G04BD09 No doses: the clinician sets them by the current guideline. On this page - The basics Mechanism of action - Indications - Adverse effects - Pharmacokinetics - Memory aid - Safety Contraindications - Key interactions - What is monitored - Administration and safety - Pregnancy and breastfeeding - Nursing care - Study Test yourself - Connections Connections ## Mechanism of action ◎**Muscarinic M3 (and M2) receptors of the bladder (antagonist)**Trospium ⓘ No trospium-bound structure exists. The figure shows tiotropium, another quaternary muscarinic antagonist, in the acetylcholine pocket of the rat M3 receptor, the subtype that contracts the bladder; the pocket is nearly identical in the human receptor. **Target in 3D:** Muscarinic M3 (and M2) receptors of the bladder (antagonist). PDB structure 4DAJ (RCSB PDB, public domain). [View the structure at RCSB PDB](https://www.rcsb.org/structure/4DAJ) · Drag to rotate · pinch to zoom Trospium blocks muscarinic receptors in the detrusor muscle of the bladder, so acetylcholine released by parasympathetic nerves causes weaker involuntary contractions; urgency, frequency and urge incontinence improve. As a quaternary ammonium compound it is charged, crosses the blood-brain barrier poorly and is less likely to cause confusion than tertiary agents such as oxybutynin. - Trospium blocks muscarinic receptors in the detrusor - Weaker involuntary bladder contractions: less urgency - Quaternary charge: little entry into the brain - Renal tubular secretion: caution in kidney disease ## Indications - Overactive bladder with urge incontinence, urgency and frequency [Overactive bladder and urge incontinence →](https://durgical.com/en/conditions/overactive-bladder-and-urge-incontinence/) ## Adverse effects ### Common - Dry mouth (the most common) - Constipation - Headache - Dry eyes and nose ### Serious (rare, important) - Urinary retention, especially with bladder outflow obstruction - Gastric retention in GI obstruction - Angioedema of the face, lips, tongue or larynx - Somnolence, confusion or hallucinations (uncommon) ## Contraindications - Urinary retention - Gastric retention - Uncontrolled narrow-angle glaucoma - Hypersensitivity to trospium ## Key interactions **Drugs actively secreted by the kidney** May compete for tubular secretion and change levels of either drug **Metformin** Lower trospium exposure **Other anticholinergic drugs** Added dry mouth, constipation and urinary retention ## What is monitored - Urinary retention and post-void residual if obstruction is suspected - Bowel habit - Kidney function ## Administration and safety - Given with water on an empty stomach, at least one hour before meals - Extended-release and immediate-release forms are different products ## Pregnancy and breastfeeding Human data are lacking; it is used only if the benefit outweighs the risk. ## Nursing care - Asks about difficulty passing urine and a weak stream - Watches for constipation and dry mouth and suggests mouth care - Reports swelling of the face, lips or tongue at once - Checks kidney function before and during treatment ## Pharmacokinetics **Absorption** Incompletely absorbed by mouth (a charged quaternary amine); taken on an empty stomach **Elimination** Mainly by the kidneys, partly by active tubular secretion; exposure rises in severe renal impairment ## Memory aid «TROSPium stays OUTSIDE the brain»: quaternary, renal, empty stomach; the bladder calms without confusion. ## Test yourself Think of the answer, then tap the question to see it. ## Why does trospium cause fewer central side effects than oxybutynin? It is a quaternary amine that crosses the blood-brain barrier poorly. ## How is trospium mainly eliminated? By the kidneys, partly through active tubular secretion. ## What is one contraindication of trospium? Urinary retention, gastric retention or uncontrolled narrow-angle glaucoma. [Add to my cards (3)](https://durgical.app/estudiar/?add=/en/pharmacology/trospium/) [More Pharmacology questions →](https://durgical.com/en/practice/?f=pharmacology) ## Connections ## Related drugs 3 - [Oxybutynin](https://durgical.com/en/pharmacology/oxybutynin/) - [Solifenacin](https://durgical.com/en/pharmacology/solifenacin/) - [Tolterodine](https://durgical.com/en/pharmacology/tolterodine/) ## Related conditions 1 - [Overactive bladder and urge incontinence](https://durgical.com/en/conditions/overactive-bladder-and-urge-incontinence/) [← Back to the class: Overactive bladder agents](https://durgical.com/en/pharmacology/classes/overactive-bladder-agents/) Educational content on how drugs work; not a prescribing guide and no substitute for a health professional's advice. No doses are given. Sources: [DailyMed - TROSPIUM CHLORIDE tablet](https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=fcb13b21-e4a2-461b-b3cb-0daedc722050) (DailyMed (U.S. National Library of Medicine), 2026); [Trospium: MedlinePlus Drug Information](https://medlineplus.gov/druginfo/meds/a604037.html) (MedlinePlus (U.S. National Library of Medicine), 2026); [ATCDDD - ATC/DDD Index](https://atcddd.fhi.no/atc_ddd_index/?code=G04BD09) (WHO Collaborating Centre for Drug Statistics Methodology, 2026). ## **Spotted a mistake?** We are always improving for the community. Tell us what is wrong and our team will review it. Report a mistake Representative model, for educational purposes only. --- Source: https://durgical.com/en/pharmacology/trospium/ License: CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). Cite as: DurgiPedia (durgical.com), https://durgical.com/en/pharmacology/trospium/