From the Guidelines
Yes, subcutaneous methotrexate can be administered in the arm. The upper arm is one of several appropriate injection sites for subcutaneous methotrexate, along with the abdomen and thigh. When injecting in the arm, the outer area of the upper arm provides adequate subcutaneous tissue for proper administration. The injection should be given by pinching a fold of skin and inserting the needle at a 45-90 degree angle, depending on the patient's body composition and needle length. Patients should rotate injection sites to prevent tissue damage and maintain absorption consistency. The standard starting dose for methotrexate is typically 7.5-15 mg once weekly, with potential adjustments based on clinical response and tolerability. Subcutaneous administration often provides better bioavailability and may cause fewer gastrointestinal side effects compared to oral administration. Patients should be advised to follow proper injection technique, including hand washing, alcohol swabbing of the injection site, and proper disposal of needles in a sharps container. According to the most recent guideline evidence 1, oral methotrexate is conditionally recommended over subcutaneous methotrexate for patients initiating methotrexate, but switching to subcutaneous methotrexate is conditionally recommended over the addition of/switching to alternative DMARD(s) for patients taking oral methotrexate who are not at target.
Some key points to consider when administering subcutaneous methotrexate include:
- Using the outer area of the upper arm as an injection site
- Pinching a fold of skin and inserting the needle at a 45-90 degree angle
- Rotating injection sites to prevent tissue damage
- Following proper injection technique, including hand washing and alcohol swabbing of the injection site
- Starting with a dose of 7.5-15 mg once weekly, with potential adjustments based on clinical response and tolerability.
It's also important to note that subcutaneous administration may provide better bioavailability and fewer gastrointestinal side effects compared to oral administration, as suggested by studies 1. However, the most recent and highest quality study 1 should be prioritized when making decisions about methotrexate administration.
From the Research
Administration of Subcutaneous Methotrexate
- Subcutaneous (sc) methotrexate can be administered, but the specific injection site may vary [(2,3,4,5)].
- Studies have shown that subcutaneous methotrexate can be effective and well-tolerated for patients with rheumatoid arthritis [(2,3,4,5)].
- The bioavailability of subcutaneous methotrexate is higher and less variable than oral methotrexate [(4,5)].
Injection Sites for Subcutaneous Methotrexate
- While the studies do not specifically mention the arm as an injection site, they do mention administration into the abdomen and thigh 5.
- It is essential to follow the recommended administration guidelines and consult with a healthcare professional for specific instructions on injection sites [(2,3,4,5)].
Efficacy and Tolerability of Subcutaneous Methotrexate
- Subcutaneous methotrexate has been shown to be effective in treating rheumatoid arthritis, with a numerically higher response rate and fewer adverse events compared to oral methotrexate [(2,4)].
- Patients who switched from oral to subcutaneous methotrexate experienced improved efficacy and tolerability [(3,4)].