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May 1983

Folate Status in Patients Receiving Maintenance Doses of Sulfasalazine

Author Affiliations

From the Department of Medicine, Southern California Permanente Medical Group, San Diego (Dr Longstreth), and the Department of Basic and Clinical Research, Scripps Clinic and Research Foundation, La Jolla, Calif (Dr Green).

Arch Intern Med. 1983;143(5):902-904. doi:10.1001/archinte.1983.00350050056012

• 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.

{Arch Intern Med 1983;143:902-904)