Colchicine treatment in children with familial Mediterranean fever.

Prophylactic colchicine therapy has been shown to be a safe and effective method of eliminating the attacks and preventing the development of amyloidosis in patients with familial Mediterranean fever (FMF). However, information about effective dosages that control FMF attacks and prevent amyloidosis in childhood is not available. The aim of this study is to determine the 'effective colchicine dose' for children in terms of body weight and surface area. Sixty-two (34 male, 28 female) children with FMF were selected and colchicine treatment was initiated by giving 0.5-1 mg/day to each patient. The dose was gradually increased up to a maximum 2 mg/day in unresponsive patients; mean duration of therapy was 45.6 +/- 35.5 months. When the 'optimal effective dosage' (i.e. the one that reduced the frequency of attacks and ESR, CRP and fibrinogen levels during the attack-free period) was achieved, the optimal effective dose was calculated according to the body weight and body surface area for each patient. Based on these values 'mean colchicine dose' was computed for the study group and values for different age groups were evaluated. Mean colchicine doses according to the body weight and surface area of the whole group were found to be 0.03 +/- 0.02 mg/kg/day and 1.16 +/- 0.45 mg/m(2)/day, respectively. It was shown that children less than 5 years of age might need colchicine doses as high as 0.07 mg/kg/day or 1.9 mg/m(2)/day. These dosages are approximately 2.5-3 times more than the 'mean colchicine dose' for children aged 16-20 years. These results clearly show that small children need higher doses of colchicine in order to control their attacks. Thus, we conclude that colchicine, when given according to body weight or body surface area, would be more effective in childhood.