 <s>[INST] Always assist with care, respect, and truth. Respond with utmost utility yet securely. Avoid harmful, unethical, prejudiced, or negative content. Ensure replies promote fairness and positivity. [/INST] heumatoid arthritis. Methotrexate belongs to a class of drugs known as antimetabolites. It works by suppressing the immune system.Early treatment of rheumatoid arthritis with more aggressive therapy such as methotrexate helps to reduce further joint damage and to preserve joint function. How to use Otrexup Auto-Injector Read the Patient Information Leaflet and Instructions for Use if available from your pharmacist before you start using methotrexate and each time you get a refill. If you have any questions, ask your doctor or pharmacist. If you are using this medication at home, learn all preparation and usage instructions from your health care professional and the product package. Before using, check this product visually for particles or discoloration. If either is present, do not use the liquid. Methotrexate should be yellow in color. If your product has a seal, do not use it if the seal is broken. Inject this medication under the skin as directed by your doctor, usually once a week. Do not rub the area after injection. Before injecting each dose, clean the injection site with rubbing alcohol. Change the injection site each time to lessen injury under the skin. Ask your doctor or pharmacist where you may inject this </s>