REFLEXES OF THE CUTANEOUS MICROCIRCULATION IN AMITRIPTYLINE AND IN FLUOXETINE TREATED PATIENTS

Cutaneous microcirculation was investigated in 30 major depressed inpa tients receiving either 150 mg amitriptyline (n = 15) or 30 mg fluoxet ine (n = 15) as monotherapy, and in 15 normal control subjects matched for age and sex. The laser Doppler flux (LDF) was recorded while rest ing and under the condition of a sudden deep breath (''inspiratory gas p response''). In normal subjects this autonomic function test caused a marked decrement of LDF signal, which rapidly returned to the baseli ne value. In both groups of drug treated patients the decrements of LD F signal after a sudden deep breath did not differ from those found in the normal control subjects, However, in the amitriptyline-treated pa tients the return of LDF-signal to the baseline values was significant ly delayed (P = 0.0007), while patients treated with fluoxetine showed the same behaviour as normal subjects. With a discriminant analysis u sing the results of the inspiratory gasp responses, 100% of the amitri ptyline treated patients were correctly classified. Since both groups of depressed patients revealed comparable depression scores, the diffe rences found are probably due to the side effects of amitriptyline. Po ssible clinical implications of these findings are discussed.