Potential to interfere w/ activity of anticholinergics eg, atropine. Synergistic effect w/ succinylcholine, other neuromuscular-blocking agents, or cholinergic agonists (eg, bethanechol). Increase gastric acid secretions w/ NSAIDs eg, ibuprofen, naproxen. Increased AUC
0-24 & C
max w/ ketoconazole. Increased rate of elimination w/ CYP3A4 & CYP2D6 inducers eg, carbamazepine, dexamethasone, phenobarb, phenytoin, rifampin.