To the Editor:
We thank Dr. Kapoor for his interest1 in our recent article on the use of subcutaneous methotrexate (MTX)2. He lists the rare side effects of this drug but fails to point out that oral MTX can also cause pneumonitis3, lymphoma4,5, and neurotoxicity6. There is no significant evidence of increased risk of side effects with subcutaneous MTX as opposed to the oral form.
We would also point out that anti-tumor necrosis factor (TNF-α) therapy has also been associated with rare but serious adverse events such as demyelination7, severe infusion reactions8, congestive heart failure9, and autoimmunity10. Therefore, these drugs and their side effects must be put into context. The longterm side effects of anti-TNF-α agents are still unknown. The balance of risks and benefits of biologic disease-modifying antirheumatic drugs can only be reliably determined when good longterm data on such effects are available.
Patient safety should not be compromised. The significant cost benefits must be taken into consideration, while at the same time keeping the risk to the patient to a minimum.
