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. Trospium chloride 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 trospium chloride was administered while fasting. Therefore, it is recommended that trospium chloride 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 trospium chloride (0.5 to 50 ng/mL) were incubated with human serum in vitro. The 3H-trospium chloride ratio of plasma to whole blood was 1.6:1. This ratio indicates that the majority of 3H-trospium chloride is distributed in plasma. The apparent volume of distribution for a 20 mg oral dose is 395 (± 140) liters.The metabolic pathway of trospium 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.
Heart valve dysplasia is a congenital heart defect which affects the aortic, pulmonary, mitral, and tricuspid heart valves. Dysplasia of the mitral and tricuspid valves can cause leakage of blood or stenosis.Dysplasia of the mitral and tricuspid valves - also known as the atrioventricular (AV) valves - can appear as thickened, shortened, or notched valves. The chordae tendinae can be fused or thickened. The papillary muscles can be enlarged or atrophied. The cause is unknown, but genetics play a large role. Dogs and cats with tricuspid valve dysplasia often also have an open foramen ovale, an atrial septal defect, or inflammation of the right atrial epicardium. In dogs, tricuspid valve dysplasia can be similar to Ebsteins anomaly in humans.Mitral valve stenosis is one of the most common congenital heart defects in cats. In dogs, it is most commonly found in Great Danes, German Shepherd Dogs, Bull Terriers, Golden Retrievers, Newfoundlands, and Mastiffs. Tricuspid valve dysplasia is most common in the Old English Sheepdog, German Shepherd Dog, Weimaraner, Labrador Retriever, Great Pyrenees, and sometimes the Papillon. It is inherited in the Labrador Retriever.The disease and symptoms are similar to progression of acquired valve disease in older dogs. Valve leakage leads to heart enlargement, arrhythmias, and congestive heart failure. Heart valve dysplasia can be tolerated for years or progress to heart failure in the first year of life. Diagnosis is with an echocardiogram. The prognosis is poor with significant heart enlargement. == References ==