Pharmacological and clinical basis of treatment of Familial Mediterranean Fever (FMF) with colchicine or analogues: an update.

Familial Mediterranean Fever (FMF), an autosomal recessive disorder, is characterised by recurrent attacks of fever and serositis, lasting 24-72 hours. Since 1972 colchicine has become the drug of choice for prophylaxis against FMF attacks and amyloidosis FMF-associated. Colchicine, an alkaloid neutral, is absorbed in the jejunum and ileum. It metabolised by liver and only small amounts are recovered unchanged in the urine. Really plasma half-life is prolonged in patients with liver or renal failure. Colchicine is able to prevent activation of neutrophils, binding beta-tubulin and making beta-tubulin-colchicine complexes; this way inhibits assembly of microtubules and mitotic spindle formation; moreover its mode of action includes modulation of chemokines, prostanoids production, inhibition of neutrophil and endothelial cell adhesion molecules. The minimal daily dose in adults is 1.0 mg/die, but in children there is not a definite dose. Since in vitro high dosages of colchicine stop mitosis, this drug might interfere with male and female fertility and with children growth, but, according to current guidelines and because of rare side effects of the drug, FMF patients are recommended to take colchicine. Since colchicine treatment is often complicated by frequent gastrointestinal side effects, by our experience, in order to improve colchicine tolerance we recommend: lactose-free diet and treatment of intestinal bacterial overgrowth and/or Hp-infection, assessed by breath tests. Since our data showed that 10-15% of FMF patients seem are non-responders or intolerant to colchicine, today we are working in the design of colchicine analogues which may have lesser toxicities and a larger therapeutic window.