Fluvoxamine or Placebo in the Treatment of Panic Disorder and Relationship to Blood Concentrations of Fluvoxamine

A six-week double-blind placebo-controlled trial of fluvoxamine was undertaken in 46 patients suffering from panic disorder with or without agoraphobia diagnosed by DSM-III-R guidelines. Average daily dosage of fluvoxamine was 160 mg, with a highest permitted dose of 300 mg/day. Weekly evaluation included a diary in which the number, severity, and duration of full-blown and limited panic attacks and the duration and severity of anticipating fear, CAS, GAS, CGI, HAM-D, adverse effects and the number of capsules not taken were noted. Fluvoxamine was not significantly superior to placebo with regard to the main outcome criterion, i.e., the reduction in the number of panic attacks, but it was significantly more effective with regard to the diminution in the number of limited panic attacks and showed a tendency to significance in respect of GAS and CGI. Plasma levels of fluvoxamine were measured at the end of week one and at the end of the study. Most patients with complete remission at the end of the study were found in the verum group with plasma fluvoxamine levels ranging from 10 to 100ng/ml. It is suggested that therapeutic response might be maximized by monitoring fluvoxamine concentrations in blood.