Thursday April 12, 2007
Drug Induced Systemic Lupus Erythematosus (DISLE)

Today's pearl contributed by
Jennifer Burns, D.Pharm
Vassar Brothers Medical Center
Poughkeepsie, NY


As many as 10% of diagnosed cases of SLE are drug-related. From Critical Care perspective there are reports of acute DISLE like fulminating hydralazine-induced lupus pneumonitis 1 , acute acalculous cholecystitis and cardiac tamponade 2.

DISLE affects males and females almost equally, whites more often than blacks, and is more common in older patients than idiopathic SLE (Kale, 1985). The average age of SLE at the time of diagnosis is 35.8 whereas that of DISLE is 60.7 and 53.5 associated with procainamide and hydralazine, respectively. This is probably due to the more frequent use of antihypertensive and antiarrhythmic medication in the older population.

There appears to be a racial difference in the incidence of DISLE, with the percentage of DISLE patients who are white being 86 to 95% for hydralazine and 95% for procainamide; likewise 64% of the patients with idiopathic SLE are white (Stratton, 1985). Symptoms of DISLE are the same as in SLE but are less severe (Weinstein, 1980).

Drugs with a hydrazine or amino group linked to an aromatic ring, such as HYDRALAZINE, PROCAINAMIDE and ISONIAZID, are most often linked to DISLE (Reidenberg, 1981). Hydralazine, procainamide, and isoniazid have been demonstrated in controlled prospective studies to cause increased ANA titers or a SLE type illness.

In those patients receiving hydralazine, DISLE is rarely seen in daily doses less than 200 milligrams. Interestingly, there is good evidence that those patients who are identified as slow acetylators are at a higher risk of developing DISLE, but a correlation between idiopathic SLE and the acetylator phenotype is poorly understood (Totoritis, 1985)(Anon, 1974). In fact, the drugs most often implicated in DISLE are all metabolized in the liver by acetylation (eg, hydralazine, procainamide, anticonvulsants, INH).


Reference:

1. Fulminating hydralazine-induced lupus pneumonitis - Arthritis Care & Research - Volume 55, Issue 3 , Pages 501 - 506

2. Acute acalculous cholecystitis and cardiac tamponade in a patient with drug-induced lupus - Rheumatology 2001; 40: 709-711