Subcutaneous methotrexate 'impressive in active RA | Arthritis Information

 Subcutaneous administration of methotrexate shows "impressive" efficacy in patients with rheumatoid arthritis (RA), research suggests.

The conclusion is based on a multicenter randomized controlled study involving 375 patients with RA and a Disease Activity Score in 28 joints of at least 4. None of the patients had previously received methotrexate or biologic agents.

The study treatment involved 24 weeks of methotrexate 15 mg/day given orally or by subcutaneous injection; dummy tablets and syringes were used so that treatment allocation was double-blinded.

By 24 weeks, the proportion of patients with a 20% improvement in the American College of Rheumatology (ACR) score was 78% in the subcutaneous group and 70% in the oral group, a statistically significant difference.

Indeed, significantly more patients taking subcutaneous than oral methotrexate achieved a 70% improvement in ACR score, at 41% versus 33%, respectively.

The ACR improvement criteria are clinically meaningful, say the authors, reflecting key disease measures such as swollen/tender joint count, blood markers of systemic inflammation, and patients' and physicians' assessments of disease activity, disability, and pain.

Importantly, tolerability was similar between the two treatments, except for diarrhea, which was more common with oral methotrexate, and loss of appetite, which was more common with subcutaneous therapy.

The study authors, led by J Braun (Rheumazentrum Ruhrgebiet, Herne, Germany), conclude that subcutaneous administration of methotrexate is superior to oral dosing, although the mechanisms underlying the difference are unclear.

"Subcutaneous administration [may be] especially useful in patients with active disease, as in our study population," Braun and co-authors write in the journal Arthritis and Rheumatism.

"The results of our study support the use of methotrexate as monotherapy in patients with RA, being the best of the currently available monotherapies for this condition."

Free abstract