SAN FRANCISCO—Co-prescription of folic acid in patients receiving low dose oral methotrexate (MTX) is recommended because it reduces adverse events and prolongs the use of the drug. A study on PLOS One suggests, however, that not enough is known about how often new users of methotrexate are co-prescribed folic acid or what factors are associated with its use.1

A study team led by researchers from the San Francisco VAMC and the University of California San Francisco sought to determine the prevalence, predictors of and persistence of folic acid use in a population-based cohort of MTX users, including those with psoriatic arthritis.

To do that, the researchers pulled data from the VHA’s national, administrative database that included pharmacy and laboratory information. The observational cohort study focused on veterans older than 65 who were new users of MTX. Overall, 2,467 incident users of MTX were reviewed.

Results indicated that 27% of patients were not prescribed folic acid through the VHA pharmacy within 30 days of MTX initiation. The report added that patients who did not see a rheumatologist were 23% less likely to receive folic acid compared to patients who did have a rheumatologist visit during the baseline period (RR (95% CI) 0.77 (0.72, 0.82).

Those results remained unchanged even after adjusting for demographic, clinical, and other factors (adjusted RR (95% CI) 0.78 (0.74, 0.85)). Furthermore, after 20 months, only 50% of patients continued to receive folic acid, the researchers emphasized.

“In a nationwide VHA cohort of new users of oral MTX, many patients did not receive folic acid or discontinued it over time,” study authors concluded. “Rheumatologists were more likely to prescribe folic acid than other providers. These data highlight the need to improve patient safety for users of methotrexate by standardizing workflows for folic acid supplementation.”

  1. Schmajuk G, Tonner C, Miao Y, Yazdany J, Gannon J, Boscardin WJ, Daikh DI, Steinman MA. Folic Acid Supplementation Is Suboptimal in a National Cohort of Older Veterans Receiving Low Dose Oral Methotrexate. PLoS One. 2016 Dec 15;11(12):e0168369. doi: 10.1371/journal.pone.0168369. eCollection 2016. PubMed PMID: 27977768; PubMed Central PMCID: PMC5158188.