Observations on Cases of Thrombocytopenic Purpura Due to Quinine, Sulphamezathine, and Quinidine

(RECEIVED FOR PUBLICATIONMARCH 26,1953) Toxicpurpura occurringin personswhohave previously beensensitized bydrug-taking often manifests itself withgreatrapidity ina matterof a few hours.Thrombocytopenia whichmay accompany this typeofpurpuracan alsooccur in a very short time. Ifthenatural life-span of platelets isaboutfivedays(Lawrence andValentine,1947;HirschandGardner, 1952)thenthis rapid onsetofthrombocytopenia seemstoindicate a peripheral destruction ofplatelets rather thana central failure ofproduction. Experiments by Ackroyd(Ackroyd, 1949a, b,andc,1951) on the bloodofpatients recovering from"sedormid" purpura demonstrated it vitrothe probable mechanism ofplatelet destruction in thiscondition.He hasshownthat"sedormid " addedto bloodfromhispatients in concentrations suchas mightbe attained invivocausedagglutination, and,inthepresenceofcomplement, lysis ofthe platelets. He foundthata plasmafactor was necessaryforthisaction, andthatinthepresence ofcomplement and"sedormid "plasma fromhis patient wouldcause agglutination and lysis of normalplatelets. We havecarried outsimilarinvestigations on three cases ofthrombocytopenic purpurawhich appeared toberelated aetiologically tosensitizationbyquinine, sulphamezathine, andquinidine.