PARENTERAL IRON THERAPY - PROBLEMS AND PO SSIBLE SOLUTIONS

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 su crose complex, primarily in relation to anaphylactic/anaphylactoid rea ctions and common exanthemas. 1. In 206 patients of the department of general internal medicine in a city/teaching hospital tin association with the Swiss Foundation for Comprehensive Hospital Drug Monitoring C HDM), 4 probably allergic reactions to i.m. iron dextran were found, o ne with acute severe dyspnea, cyanosis and flush, 3 with slight genera lized, probably allergic reactions. Data from the USA on i.v. iron dex tran do not show marked differences in the frequency of ADRs as compar ed with our data with i.m. administration. 2. A group of 400 otherwise healthy patients of the obstetric department of Zurich University Hos pital were treated with i.v. iron sucrose for anemia due to iron loss during pregnancy or following childbirth. Seven generalized skin react ions, 4 in the form of flush and 3 of common exanthema, occurred. 3. I n a retrospective study on patients on maintenance hemodialysis with c hronic renal insufficiency and anemia, a questionnaire was answered by the medical heads of 17 selected hemodialysis units in Switzerland. R esponse 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, a nd one each with urticaria and vomiting/diarrhea. 4. The relatively go od tolerance of i.v. iron sucrose in patients with chronic renal failu re may be due either to reduced immune competence in patients with chr onic renal insufficiency and/or to the use of the preparation itself, or probably both. 5. In ADRs of allergic appearance to iron sucrose, t he 7 generalized skin reactions occurred on the first day of the injec tions, as did those under iron dextran. Preexisting hypersensitivity m ust be taken into consideration. 6. If our experience is confirmed, pr eventive measures with i.v. iron sucrose, mainly in patients with chro nic renal insufficiency, could be reduced.