Abstract: This invention relates to a process for the treatment of patients suffering from drepanocytosis, comprising administering to said patients a therapeutically effective dosage of a pyridine derivative having the formula: ##STR1## in which X is oxygen or sulfur; R is oxygen or a phenyl optionally substituted with at least a halogen, lower alkyl, lower alkoxy, nitro, amino, sulfonylamino, aryl, carboxy, alkoxycarbonyl, cyano, hydroxymethyl or methylenedioxy group; styryl, naphthyl, thienyl or benzhydryl optionally substituted with at least a halogen, lower alkyl, lower alkoxy, aryl, nitro, amino, sulfonylamino, carboxyl, alkoxycarbonyl, cyano, hydroxymethyl or methylenedioxy group; benzoyl optionally substituted with at least a halogen, lower alkyl, lower alkoxy, nitro, amino or sulfonylamino group; R.sub.1 and R.sub.2 each represent at least one atom or group selected from hydrogen, halogen, hydroxy, lower alkyl, lower alkoxy, nitro or amino; R.sub.