Optimal administration and dosage of methotrexate

Methotrexate (MTX) has been used for the treatment of rheumatic diseases, especially rheumatoid arthritis (RA), for some decades now. Although it had been known from pharmacokinetic studies for quite some time already that the bioavailability of MTX is superior when administered parenterally rather than orally, this had never been formally proven to be clinically relevant. In a recent randomised clinical trial, the two ways of administration have been directly compared. The fact that the patient group that received MTX s.c. had better clinical outcome than the oral group can be considered as proof that this hypothesis has now been confirmed. Although this result does not mean that every patient will be in need of parenteral administration of MTX, it suggests that very active patients and those with a worse prognosis may have more benefit from this strategy.