These drugs cause an autoimmune response (the body attacks its own cells) producing symptoms similar to those of systemic lupus erythematosus (SLE).

[citation needed] A predisposing factor to developing DIL is N-acetylation speed, or the rate at which the body can metabolize the drug.

[3] These metabolites (byproducts of the interactions between the drug and constituents in the body) of hydralazine are said to have been created when white blood cells have been activated, meaning they are stimulated to produce a respiratory burst.

[4] Respiratory burst in white blood cells induces an increased production of free radicals and oxidants such as hydrogen peroxide.

Approximately 5% of the patients who have taken hydralazine over long periods of time and in high doses have shown DIL-like symptoms.

The most common medications associated with drug induced lupus are hydralazine, procainamide, isoniazid, methyldopa, chlorpromazine, quinidine, and minocycline.