Use of tacrine has been associated with elevations in serum transaminases. Use extreme caution in current evidence of history of abnormal liver function tests. May cause loose stools, nausea and/or vomiting. May be associated with neutropenia. Cholinesterase inhibitors may have vagotonic effects which may cause bradycardia and/or heart block with or without history of cardiac disease. Tacrine may cause bradycardia and/or heart block (use with caution in sick-sinus syndrome, bradycardia, or conduction abnormalities). Use with caution in risk of ulcer disease (e.g. previous history or NSAID use); may increase gastric acid secretion, in COPD and/or asthma, in history of seizure disorder, and in bladder outlet obstruction or prostatic hyperplasia. Cholinomimetics may cause or worsen outflow obstructions, including possible exacerbation of BPH symptoms. May exaggerate neuromuscular blockade effects of depolarizing neuromuscular-blocking agents such as succinylcholine. Abrupt discontinuation or dosage decrease may worsen cognitive function.