Mental Status, the Intensive Care Unit, and Cimetidine

Abstract

A blind, prospective study of the association between cimetidine treatment and altered mental status (MS) was evaluated in 217 surgical intensive care patients stratified by the degree of renal or hepatic dysfunction, or both. The cimetidine and noncimetidine groups did not differ in blood chemistries, physiologic-metabolic data or concurrent medications. There was a correlation between treatment with cimetidine and changes in MS (P < 0.0001). The MS changes with cimetidine ranged from 33% for neither hepatic nor renal dysfunction to 80% for both renal and liver dysfunction to 80% for both renal and liver impairment. The magnitude of MS change was influenced by disease and serum concentration, with patients with both renal and liver disease having the greatest MS change at the highest serum concentrations. The type of MS change was also disease specific. All MS change cleared within 24-36 h of stopping the drug. Apparently, both dose and underlying disease state are important factors in determining the nature and severity of cimetidine-associated mental status changes.