This letter is a response to the letter from Bhowmik and Tiwari [1] concerning the safety of sodium ferric gluconate complex (SFGC). Of all the formulations of intravenous iron, SFGC has been prospectively studied most extensively. The SFGC safety study [2] enrolled 2534 SFGC-naïve haemodialysis patients in 69 US centers. These patients were randomized in a double-blind crossover protocol to receive placebo or 125 mg of intravenous (IV) SFGC over 10 min without a test dose. One patient (0.04%) experienced a life-threatening reaction after SFGC infusion (back pain, nausea, vomiting, diaphoresis, wheezing), which fully responded to medical therapy and did not require discontinuation of their dialysis session or hospitalization. Drug intolerance, defined as any event that precluded re-exposure to study drug, occurred in 0.4% of SFGC-treated and 0.1% of placebo-treated patients (P = 0.02). There was no difference in the rate of serious adverse events following SFGC as compared to placebo.
In the surveillance study [3], 1321 haemodialysis patients received 13 151 infusions of SFGC at an investigator determined dose and infusion rate over a 9 month period. The majority of doses were given as 125 mg IV over 10 min. There were no life-threatening events. One patient (0.1%) experienced a serious adverse event (hypotension) felt to be related to rapid infusion of SFGC. This patient was successfully treated in the dialysis unit and went on to receive further doses of SFGC without complication. Five patients (0.4%) were drug intolerant due to: pruritus (three), vasodilatation (one) and loss of taste (one). This rate of intolerance was the same as seen in the safety study.
Coyne [4] compared anaphylactic reactions to iron products recorded in spontaneous reporting databases. In this analysis, SFGC had fewer reported events, both by events per dose and events per patient, as compared to iron dextran and iron sucrose. Conclusions of retrospective reviews of spontaneous adverse drug event reporting [5] cannot compare to prospective evaluations of drug safety. For SFGC, these studies have already been performed.
Conflict of interest statement. Dr Michael serves on the speaker's bureau and advisory board, and has received grant support for clinical trials, from Watson Pharmaceuticals, the maker of SFGC.
Thomas Jefferson University Division of Nephrology Philadelphia PA 19107 Email: beckie.michael{at}jefferson.edu
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