L. E. Böttiger

Because of the wide range of plasma factor VIII concentrations found in normal donors, and the inaccuracy of assays on concentrated material, the best basis on which to calculate the appropriate dose of concentrate for a given situation is the factor VIII concentration of the original plasma from which the cryoprecipitate was prepared. If this is known the dose can be calculated without waiting for the result of an assay performed on the reconstituted material, applying a correction factor to account for the expected recovery, as described above. In practice, however, it may not always be possible to assay the original plasma, and in such a case the following formula may be used as a rough guide:

Cases of drug-induced aplastic anaemia, haemolytic anaemia, thrombocytopenia, and agranulocytosis reported to the Swedish Adverse Drug Reaction Committee during the five-year period 1966-70 have been analysed and compared with cases of the same cytopenias from "all" causes. Oral diuretics were a dominant cause of drug-induced thrombocytopenia, methyldopa of haemolytic anaemia, and oxyphenbutazone of aplastic anaemia. Computer systems should help such studies, particularly in showing a changing pattern of complications and causes.