How Otrexup Is Administered
Otrexup delivers methotrexate subcutaneously via a single-use, prefilled auto-injector. Users press the device firmly against clean, dry skin on the abdomen or thigh, hold for 2 seconds until a click sounds, and the full dose injects automatically. It comes in strengths from 7.5 mg to 25 mg per 0.4 mL, injected once weekly. Do not inject into the same site consecutively.
What Conditions Does Otrexup Treat?
Otrexup treats active rheumatoid arthritis in adults, polyarticular juvenile idiopathic arthritis in children 2 years and older, and severe psoriasis in adults unresponsive to other therapies. Off-label, it's used for some cancers under medical supervision.
Proper Dosing Guidelines
Dosing starts at 7.5 mg weekly for rheumatoid arthritis and psoriasis, up to 25 mg based on response. For juvenile arthritis, it's 10 mg/m² weekly, capped at 25 mg. Take folic acid supplements to reduce side effects. Skip missed doses; do not double up. Storage: Refrigerate at 36-46°F (2-8°C); allow to warm to room temperature before use.
Step-by-Step Injection Instructions
- Wash hands and choose injection site (avoid scars, bruises, or belly button).
- Remove cap; do not touch needle.
- Press and hold device against skin until click; count to 10.
- Dispose in sharps container; do not recap.
Full instructions are in the prescribing information or patient guide from the manufacturer.
Common Side Effects and Precautions
Watch for nausea, fatigue, mouth sores, hair loss, or liver issues. Serious risks include infections, lung problems, or birth defects—avoid pregnancy and use contraception. Get blood tests regularly to monitor. Inform doctor of alcohol use, vaccinations, or other drugs like NSAIDs, as interactions occur.
How Otrexup Differs from Oral Methotrexate
Otrexup bypasses stomach absorption issues, providing consistent blood levels for better efficacy in non-responders to pills. It's more expensive but convenient for weekly home use.
[1] Otrexup Prescribing Information
[2] Antares Pharma (Manufacturer) Patient Resources
[3] Drugs.com Otrexup Details