Adverse effects of lithium therapy in the acutely ill elderly patient.

The incidence of adverse effects of lithium therapy was compared between inpatients age 65 and older and those under the age of 65 to determine if the elderly patients were more susceptible to adverse effects. A retrospective chart review was utilized to determine the respective incidences. While there is no significant difference between the groups with regard to overall incidence of adverse effects, there is a significantly greater (p less than 0.02) incidence of moderate to severe adverse effects in the elderly. An attempt was made to determine what predisposes the elderly patient to this apparent increased sensitivity, but due to sample size, only trends could be determined. Methods of decreasing the frequency of lithium toxicity in the elderly are suggested.