[Parenteral iron therapy: problems and possible solutions]

Abstract

To investigate whether there are differences in the frequency of ADRs (adverse drug reactions) to parenteral iron preparations, we compared the results of 4 different data collections which contain observations in particular on i.m. or i.v. iron dextran and i.v. iron hydroxide sucrose complex, primarily in relation to anaphylactic/anaphylactoid reactions and common exanthemas. 1. In 206 patients of the department of general internal medicine in a city/teaching hospital (in association with the Swiss Foundation for Comprehensive Hospital Drug Monitoring--CHDM), 4 probably allergic reactions to i.m. iron dextran were found, one with acute severe dyspnea, cyanosis and flush, 3 with slight generalized, probably allergic reactions. Data from the USA on i.v. iron dextran do not show marked differences in the frequency of ADRs as compared with our data with i.m. administration. 2. A group of 400 otherwise healthy patients of the obstetric department of Zurich University Hospital were treated with i.v. iron sucrose for anemia due to iron loss during pregnancy or following childbirth. Seven generalized skin reactions, 4 in the form of flush and 3 of common exanthema, occurred. 3. In a retrospective study on patients on maintenance hemodialysis with chronic renal insufficiency and anemia, a questionnaire was answered by the medical heads of 17 selected hemodialysis units in Switzerland. Response was 100%. During around 8100 patient-years with approximately 160,000 ampoules of iron sucrose (with 100 mg elementary iron), not a single life threatening reaction was observed; only 5-7 situations of rapidly reversible blood pressure fall occurred, some 10 with flush, and one each with urticaria and vomiting/diarrhea. 4. The relatively good tolerance of i.v. iron sucrose in patients with chronic renal failure may be due either to reduced immune competence in patients with chronic renal insufficiency and/or to the use of the preparation itself, or probably both. 5. In ADRs of allergic appearance to iron sucrose, the 7 generalized skin reactions occurred on the first day of the injections, as did those under iron dextran. Preexisting hypersensitivity must be taken into consideration. 6. If our experience is confirmed, preventive measures with i.v. iron sucrose, mainly in patients with chronic renal insufficiency, could be reduced.