Spasmolyt Drug Interactions

Pharmacodynamic interactions: The following potential pharmacodynamic interactions may occur: Potentiation of the effect of drugs with anticholinergic action (such as amantadine, tricyclic antidepressants), enhancement of the tachycardic action of β-sympathomimetics; decrease in efficacy of prokinetic agents (e.g. metoclopramide).
Since trospium chloride may influence gastrointestinal motility and secretion, the possibility cannot be excluded that the absorption of other concurrently administered drugs may be altered.
Pharmacokinetic interactions: An inhibition of the absorption of trospium chloride with drugs like guar, cholestyramine and colestipol cannot be excluded. Therefore, the simultaneous administration of these drugs with trospium chloride is not recommended.
Metabolic interactions of trospium chloride have been investigated in vitro on cytochrome P450 enzymes involved in drug metabolism (P450, 1A2, 2A6, 2C9, 2C19, 2D6, 2E1, 3A4). No influence on their metabolic activities was observed. Since trospium chloride is metabolised only to a low extent and since ester hydrolysis is the only relevant metabolic pathway, no metabolic interactions are expected.
Though trospium chloride was shown not to affect pharmacokinetics of digoxin, an interaction with other active substances eliminated by active tubular secretion cannot be excluded.