9As described in detail by Ben-Chetrit in the previous chapter, colchicine is the mainstay of the treatment of familial Mediterranean fever (FMF) [ 1 , 2 ]. If used daily for lifelong, it controls the febrile attacks in the majority of the patients and prevents the development of amyloidosis, the most serious complication of the disease.Colchicine is very effective as shown in controlled trials [ 3 ] and within the therapeutic range. Side effects are rare and/or mild, so that it can be used even during pregnancy and lactation, plus it is very cheap; however, even colchicine has some limitations in the treatment of FMF:1. Response to therapy: A small proportion of patients with FMF continue to experience attacks despite proper dose and good compliance to colchicine. Overall, it has been accepted that colchicine prevents febrile attacks in more than 60 % of patients and signifi cantly reduces the number of attacks in another 20-30 %. Five to ten percent of patients do not respond to therapy [ 4 , 5 ].Compliance is a main issue among patients who report attacks under colchicine treatment. Approximately 40 % of the patients are not compliant and receive lower than the dose needed to control the infl ammatory attacks and thus prone to high risk of amyloidosis [ 6 ]. Therefore, it is very important to check the compliance and the daily dose before diagnosing the patient as unresponsive to colchicine therapy. Recently the data that comes from the Eurofever Registry which collects information on patients with various autoinfl ammatory diseases, including FMF, showed that among the 121 FMF patients on colchicine, 62 % reported complete, 36 % partial, and 2 % no response [ 7 ]. In another recent report, only 5 % of the compliant patients on proper dose of colchicine continued to experience frequent attacks [ 8 ].