Primary granulocytopenia due to hypersensitivity to amidopyrine

Abstract

1. 1. In a series of 19 patients observed by us the onset of acute primary granulocytopenia was directly preceded by the use of amidopyrine alone or in combination with a barbiturate. A similar relationship has been reported in the literature and by personal communication in 52 additional cases. 2. 2. The administration of a single dose of amidopyrine to each of two patients who had recovered from the acute disease was followed by a rapid profound fall in the total and granulocyte counts. 3. 3. All patients under our observation who recovered from the acute disease and avoided the use of amidopyrine have had no recurrences over periods of from twelve to thirty-one months. 4. 4. Skin sensitivity to amidopyrine was demonstrated in two of these patients by patch testing, and systemic reactions with marked depression of the total and granulocyte counts and elevation of temperature were present in both after application of a 10 per cent solution of amidopyrine to the unabraded skin. 5. 5. On the basis of this evidence we believe that acute primary granulocytopenia can be caused by repeated administration of amidopyrine to persons who have developed allergic or anaphylactoid hypersensitivity to that drug. From analogy we believe that certain other drugs may be responsible for a similar granulocytic response.