What the label lists and what reports show
Trospium side effects
Trospium's FDA label: “The most common adverse reactions (greater than or equal to 1%) with trospium chloride are dry mouth (20.1%), constipation (9.6%), and headache (4.2%).” FAERS holds 2,273 reports naming it through July 30, 2026; the reaction reported most often, leaving out the conditions it is used for, product-use terms and outcomes, is fall (178 reports).
- Generic listed
Check it at the source: the trospium FDA label on DailyMed (effective December 30, 2025, Glenmark Pharmaceuticals Inc., USA); the FDA FAERS public dashboard.
What does the patient leaflet say about side effects?
From the patient leaflet: What are the possible side effects of trospium chloride tablets?Trospium chloride tablets may cause allergic reactions that may be serious. Symptoms of a serious allergic reaction may include swelling of the face, lips, throat or tongue. If you experience these symptoms, you should stop taking trospium chloride tablets and get emergency medical help right away. The most common side effects with trospium chloride tablets are: • dry mouth; • constipation; • headache. Trospium chloride tablets may cause other less common side effects, including: • trouble emptying the bladder; • blurred vision; and drowsiness. Do not drive or operate heavy machinery until you know how trospium chloride tablets affect you. Alcohol can worsen the drowsiness caused by drugs such as trospium chloride tablets. • heat prostration. Due to decreased sweating, heat prostration can occur when drugs such as trospium chloride tablets are used in a hot environment. […]
Source: FDA drug label, Glenmark Pharmaceuticals Inc., USA, effective December 30, 2025 (SPL set d5c837a4-d1c6-4615-b7ad-27f3162a03aa), via openFDA; the full label on DailyMed
What does the label list?
From the label: adverse reactionsThe most common adverse reactions (greater than or equal to 1%) with trospium chloride are dry mouth (20.1%), constipation (9.6%), and headache (4.2%).
Table 1: Incidence (%) of adverse reactions with Trospium Chloride Tablets, reported in ≥ 1% of all patients treated with Trospium Chloride Tablets and more frequent with Trospium Chloride Tablets (20 mg twice daily)…
This table is printed in the TROSPIUM CHLORIDE label published by Padagis US LLC of April 30, 2023; the label quoted above does not print one.
| Adverse Reaction | Placebo (N=590) | Trospium Chloride Tablets 20 mg twice daily (N=591) |
|---|---|---|
| Dry mouth | 34 (5.8) | 119 (20.1) |
| Constipation | 27 (4.6) | 57 (9.6) |
| Abdominal pain upper | 7 (1.2) | 9 (1.5) |
| Constipation aggravated | 5 (0.8) | 8 (1.4) |
| Dyspepsia | 2 (0.3) | 7 (1.2) |
| Flatulence | 5 (0.8) | 7 (1.2) |
| Headache | 12 (2.0) | 25 (4.2) |
| Fatigue | 8 (1.4) | 11 (1.9) |
| Urinary retention | 2 (0.3) | 7 (1.2) |
| Dry eyes | 2 (0.3) | 7 (1.2) |
Rows and numbers as the label prints them, under its own column headings (the first rows of a longer table where it runs on). A reaction in a trial table is not necessarily caused by the medicine, and trials differ from everyday use.
From the label: adverse reactions, continuedThe most common adverse reactions (greater than or equal to 1%) with trospium chloride are dry mouth (20.1%), constipation (9.6%), and headache (4.2%). ( 6.1 ) To report SUSPECTED ADVERSE REACTIONS, contact Glenmark Pharmaceuticals Inc., USA at 1 (888) 721-7115 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch. 6.1 Clinical Trials Experience Because clinical trials are conducted under widely varying conditions, the adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in clinical practice. The safety of trospium chloride was evaluated in controlled clinical trials in a total of 2975 patients, who were treated with trospium chloride (N=1673), placebo (N=1056) or active control medications (N=246). Of this total, 1181 patients participated in two, 12-week, U.S., efficacy and safety studies and a 9-month open-label extension. Of this total, 591 patients received trospium chloride 20 mg twice daily. In all controlled trials combined, 232 and 208 patients received treatment with trospium chloride for at least 24 and 52 weeks, respectively. In all placebo-controlled trials combined, the incidence of serious adverse events was 2.9% among patients receiving trospium chloride 20 mg twice daily and 1.5% among patients receiving placebo. …
Source: FDA drug label, Glenmark Pharmaceuticals Inc., USA, effective December 30, 2025 (SPL set d5c837a4-d1c6-4615-b7ad-27f3162a03aa), via openFDA; the full label on DailyMed
What do FAERS reports show?
2,273 reports list trospium among the medicines taken, each a report of something that happened, not proof the medicine caused it; 177 are coded as a death and 901 as a hospital stay. Counts follow how widely a medicine is used and watched, and they are not a measure of how risky it is. Of the 22 reactions below, 6 are named by the same term (in US spelling) in the label's adverse reactions, warnings or patient leaflet; a reaction the label does not name may still be there under another word, and a report does not show that the medicine caused it.
Reports received each year
The 25 most reported reactions
Source: FDA Adverse Event Reporting System (FAERS) via openFDA, reports through July 30, 2026; reactions as MedDRA preferred terms
What next?
- Trospium: the full record
- label, generics, price, shortages, recalls
- Report a side effect to the FDA
- MedWatch
- Side effects hub
- the most reported medicines and reactions