Adverse events and tolerability of the combination of fluoxetine/lithium compared with fluoxetine.

Data from an intensive observational drug utilization study were analyzed to determine whether patients who received the combination of fluoxetine and lithium had more and different adverse events as compared with those receiving fluoxetine alone. In a matched cohort control design, we compared 110 patients per group. Results showed no significant difference in side effects between groups. Also, the incidence of "serotonergic" adverse events showed no significant differences between groups during the 7-week study period. In conclusion, the results show that the combination of fluoxetine/lithium is generally well tolerated in spite of a somewhat increased rate of minor side effects.