After oral administration, less than 10% of the dose is absorbed. Mean absolute bioavailability of a 20 mg dose is 9.6% (range: 4.0 to 16.1%). Peak plasma concentrations (Cmax) occur between 5 and 6 hours post-dose. Mean Cmax increases greater than dose-proportionally; a 3-fold and 4-fold increase in Cmax was observed for dose increases from 20 mg to 40 mg and from 20 mg to 60 mg, respectively. AUC exhibits dose linearity for single doses up to 60 mg.<unk>  exhibits diurnal variability in exposure with a decrease in Cmax and AUC of up to 59% and 33%, respectively, for evening relative to morning doses. Administration with a high fat meal resulted in reduced absorption, with AUC and Cmax values 70 to 80% lower than those obtained when<unk>  was administered while fasting. Therefore, it is recommended that<unk>  should be taken at least one hour prior to meals or on an empty stomach. Protein binding ranged from 50 to 85% when concentration levels of<unk>  (0.5 to 50 ng/mL) were incubated with human serum in vitro. The 3H-trospium<unk>  ratio of plasma to whole blood was 1.6:1. This ratio indicates that the majority of 3H-trospium<unk>  is distributed in plasma. The apparent volume of distribution for a 20 mg oral dose is 395 (± 140) liters. The metabolic pathway of<unk>  in humans has not been fully defined. Of the 10% of the dose absorbed, metabolites account for approximately 40% of the excreted dose following oral administration. The major metabolic pathway is hypothesized as ester hydrolysis with subsequent conjugation of benzylic acid to form azoniaspironortropanol with glucuronic acid. Cytochrome P450 is not expected to contribute significantly to the elimination of<unk> . Data taken from in vitro human liver microsomes investigating the inhibitory effect of<unk>  on seven cytochrome P450 isoenzyme substrates (CYP1A2, 2A6, 2C9, 2C19, 2D6, 2E1, and 3A4) suggest a lack of inhibition at clinically relevant concentrations. The plasma half-life for<unk>  following oral administration is approximately 20 hours. After oral administration of an immediate-release formulation of 14C-trospium<unk> , the majority of the dose (85.2%) was recovered in feces and a smaller amount (5.8% of the dose) was recovered in urine; 60% of the radioactivity excreted in urine was unchanged<unk> . The mean renal clearance for<unk>  (29 L/hour) is 4-fold higher than average glomerular filtration rate, indicating that active tubular secretion is a major route of elimination for<unk> . There may be competition for elimination with other compounds that are also renally eliminated.
Trospium chloride
Tiratricol
Octatropine methylbromide
Pilocarpine
Hyoscine butylbromide
Tolperisone
Cyfluthrin
Beclamide