Folate status in patients receiving maintenance doses of sulfasalazine.
Hematologic studies, including serum and RBC folate assays, were done on 45 outpatients with chronic colitis who either took sulfasalazine (n = 27) or did not use it (n = 18). Overall, sulfasalazine users and nonusers had similar mean hemoglobin, hematocrit, serum folate, and RBC folate levels. However, within the drug users, RBC folate was inversely correlated with drug dose; serum folate was not. Patients taking 2 g or more of sulfasalazine daily had lower mean RBC folate levels (221.2 +/- 27.3 ng/mL) than patients either taking less (371.7 +/- 35.0 ng/mL) or nonusers (330.3 +/- 30.3 ng/mL). Mean corpuscular volume was also related to drug dose but not to RBC folate. Although maintenance sulfasalazine use rarely causes clinically significant folate deficiency, subclinical tissue depletion occurs as a dose-related effect.
D003092:Colitis / Q000188:drug therapy*; D004912:Erythrocytes / Q000032:analysis*; D005492:Folic Acid / Q000097:blood / Q000378:metabolism*; D005494:Folic Acid Deficiency / Q000139:chemically induced; D006801:Humans; D012460:Sulfasalazine / Q000009:adverse effects / Q000627:therapeutic use*
D012460:Sulfasalazine; D005492:Folic Acid