PATIENTS AT RISK OF HYDRALLAZINE-INDUCED LUPUS CAN BE IDENTIFIED

... Slow Acetylators, Especially Women, Seem To Be Most Susceptible Acetylator phenotyping is a useful way to. identify patients who risk exhibiting hydrallazine lupus. 'These are slow acetylators, especially females treated with more than 1 OOmg of hydralazine daily.' Of 25 women and 6 men in whom a lupus-like syndrome had occurred during trea~ment with hydrallazine ('Aspresolin'), 29 were slow acetylators. Dosage for 2/3 of the patients was I 00-200mg daily. Only 2 received more than 200mg/ day. Two were given less .than I OOmg/ day. The mean duration oftherapy at the onset of symptoms was 3 2 months.

'Large doses during prolonged periods are commonly considered to be necessary for the occurrence of the lupus syndrome. 'The daily dosage ofhydrallazine is low in this Swedish study compared with some reports and ... 'it seems unjustified to assume that the higher plasma concentrations of unchanged hydralazine in slow acetylators are responsible for the lupus syndrome.

Strandberg.!. et al.: Acta Me~ica Scandinavica 200: 367 (No 5, 1976)