Oral methotrexate may not be the best route of delivery, say researchers who found the drug was more effective as an initial therapy in early RA if it was given subcutaneously.

The observational comparative effectiveness trial of 666 patients with early disease (417 oral, 249 s/c) participating in the CATCH study found that at one year 49% of the patients treated with subcutaneous MTX had changed treatment compared with 77% treated with oral MTX.

Patients on subcutaneous MTX — at an average dose of 22.3mg vs 17.2mg/week — also had a lower mean DAS-28 score over the first year and a small difference in achieving remission.

However no difference was seen in sustained remission or HAQ-DI, the study authors reported in the Annals of the Rheumatic Diseases. 

Their finding could be related to the differences in bioavailability between the two methods of administration, the researchers from several institutions in Canada suggested.

“Whether oral or subcutaneous MTX should be the first treatment choice warrants further study, there is certainly little evidence to support oral MTX as the preferred route of delivery as has previously been recommended,” they conclude.