Unwanted symptoms in depressed patients treated with viloxazine: an algorithm for identification of illness-related symptoms.

Ninety-six depressed outpatients from 5 centres were given viloxazine 200-400 mg/day. The treatment produced significant clinical improvement as evaluated by the Hamilton Rating Scale for Depression. Thirteen patients dropped-out because of possible side effects. Many untoward symptoms were described by all the patients. To distinguish between illness-related symptoms (IRSs) and potential side effect symptoms (SESs) a new approach was taken, using an algorithm that provides a decision strategy based on the time course both of the symptom and the illness. By this procedure, 90 of the 187 claimed untoward symptoms were identified as IRSs. Of the 97 potential SESs, only 36 were spontaneously volunteered, and the remaining 61 symptoms were elicited on specific questioning. Whenever possible, volunteered potential SESs were assessed to determine the relationship between the drug treatment and the adverse reaction. It was found that only a few instances of gastric disturbance and exacerbation of anxiety were probably viloxazine-related.