Antimuscarinic delirium (AMD) is a common and dangerous toxicology condition caused by poisoning by medications and other chemicals that block muscarinic receptors. Physostigmine, the standard antidote for AMD, currently has very limited availability in the United States due to an interruption of production.
Recent case reports and small observational studies suggest that rivastigmine might be useful in the treatment of AMD, but there is not direct prospective evidence comparing rivastigmine to physostigmine or supportive care. In order to investigate the effectiveness of rivastigmine, the investigators propose a randomized, placebo-controlled clinical trial of rivastigmine for AMD. The investigators hypothesize that patients treated with rivastigmine for antimuscarinic delirium will experience more rapid resolution of agitation and delirium than those treated with placebo.