LUPUS ANTICOAGULANT IN THE ELDERLY MAY BE ASSOCIATED WITH BOTH QUININE AND QUINIDINE USAGE

Thirty-one patients aged over 60 yrs and with lupus anticoagulant (LA) were reviewed for their drug intake. Twenty-three (73%) were taking c inchona alkaloids, 10 (32%) quinine for night cramps, 11 (35%) quinidi ne for cardiac arrhythmia and 2 (6%) were taking both. These frequenci es of drugs usage differed significantly from age and sex matched cont rols (p<0.001). Five patients had features suggestive of the antiphosp holipid syndrome. Repeat testing showed persistent LA activity in all but 2 of 5 patients in whom the relevant drug had been ceased. This is the first description of a possible causal association between LA and quinine therapy.