How to Use Otrexup Auto-Injector for Rheumatoid Arthritis
Otrexup delivers methotrexate subcutaneously once weekly for RA treatment, typically 7.5 mg to 25 mg based on doctor instructions. It comes in prefilled auto-injectors (0.4 mL to 1 mL doses). Always follow your prescription and consult your doctor or pharmacist before first use.[1]
Step-by-Step Injection Instructions
- Prepare: Wash hands. Choose an injection site (abdomen, thigh, or outer upper arm; rotate sites weekly). Clean skin with alcohol swab; let dry. Remove injector cap by twisting off (do not touch needle end).
- Position: Remove orange safety cap by pulling straight up (do not twist). Hold injector like a dart with needle end down.
- Inject: Place needle end flat against skin at 90-degree angle. Press button fully down and hold for 5 seconds (count slowly: "1-2-3-4-5"). You hear a click; needle retracts automatically.
- Finish: Dispose of used injector in FDA-approved sharps container. Do not recap.
Full visual guide in package insert or at Otrexup.com.[1][2]
Best Sites and Timing for RA Patients
Inject same day/time weekly (e.g., Sunday morning). For abdomen/thigh, pinch skin if needed; avoid 2 inches around navel or scars. Upper arm needs helper. Morning dosing minimizes nausea common in RA methotrexate therapy.[1][3]
What If the Injection Doesn't Work Right?
- No click or button sticks: Do not reuse; get new injector.
- Blood at site: Normal; apply pressure, no bandage needed.
- Leaking: Dose incomplete; contact doctor—may need supplemental dose.
- Pain/swelling: Ice briefly; report persistent issues.
Storage and Handling Before Use
Keep refrigerated (36-46°F); can store at room temp up to 77°F for 14 days max. Do not freeze or expose to heat/light. Check expiration; discard if discolored/particles present.[1]
Common RA Patient Mistakes to Avoid
Reusing injectors (single-use only), injecting same site repeatedly (causes irritation), or pressing button too soon (needle may not deploy). Folic acid supplements often prescribed alongside to reduce side effects like fatigue or mouth sores.[3][4]
When to Call Your Doctor
Before first dose, if pregnant/planning pregnancy (methotrexate contraindicated), or experiencing severe nausea, infection signs, or breathing issues. RA monitoring includes blood tests every 4-8 weeks.[4]
[1]: Otrexup Prescribing Information (FDA)
[2]: Otrexup Instructions for Use
[3]: Arthritis Foundation Methotrexate Guide
[4]: American College of Rheumatology RA Guidelines