Speech dysfunction due to trazodone-fluoxetine combination in traumatic brain injury

New serotonin reuptake inhibitors are available for the treatment of affective disorders and sleep dysfunction in traumatic brain injury TBI patients Commonly reported serotonergic side effects include nausea headache dizziness nervousness and orthostatic hypotension Trazodone a non selective serotonin reuptake inhibitor is often used in conjunction with fluoxetine a selective ser otonin reuptake inhibitor in order to combat the insomnia associated with fluoxetine Successful use of this combination is generally limited by the cumulative serotonergic side effects of the two medica tions This paper describes the first reported case of speech dysfunction as a complication of combined trazodone and fluoxetine use A 43 year old male suffered bilateral wrist fractures and a moderate TBI during a fall Within 1 week of adding fluoxetine to trazodone the patient developed new onset dysarthria and speech blocking Upon discontinuation of fluoxetine speech returned to normal Possible mechanisms include inhibition of hepatic metabolism unmasking of caudate nucleus injury increased noradrenergic activity or previously unreported serotonergic effects This case illustrates the importance of monitoring drug combinations for unexpected side effects in the TBI population