Absorption and Side‐Effects after Peroral Administration of Sustained Release Iron Tablets

Abstract

Three studies were done in 13 iron deficient patients. In the 1st study, the absorption from 100 mg ferrous sulfate (Ferro-Retard) after 3 and 5 h was comparable to the absorption from 176 mg ferrous gluconate in rapidly disintegrating tablets (Ferronicum). In the 2nd study, the serum Fe elevation in 14 blood donors with normal Hb after administration of ferrous sulfate (100 mg Fe2+) in Ferro-Retard or Duroferon Duretter seemed to be equal when tested on the 4th day after donation of 450 ml blood. The Fe absorption, measured by the elevation of serum iron 5 and 8 h after administration of sustained release tablets, proved to be better on the 11th and especially on the 16th day than on the 4th day after donation. Side effects were investigated in the 3rd study. In 113 subjects the total number of complaints was unusually high both before and after administration of placebo, rapidly disintegrating and sustained release ferrous sulfate tablets. The selection of participants and other methodological factors were probably of importance. Comparisons between different studies of side-effects should always be carried out with caution.