Makindo Medical Notes

Always check the BNF entry for Abatacept for the most up-to-date dosing and safety advice. Abatacept is a specialist drug used in inflammatory arthritis where standard DMARDs have failed.

⚙️ Mode of Action

• 🛡️ T-cell activation inhibitor.
• It is a soluble fusion protein: CTLA-4 linked to the Fc portion of IgG1 (CTLA4-Ig).
• Prevents co-stimulatory signalling needed for full T-cell activation → dampens autoimmune inflammation.

💊 Indications

• 🤲 Moderate-to-severe Rheumatoid Arthritis (specialist use only).
• 🧴 Psoriatic Arthritis (specialist use only).

📌 Dosing (must always check BNF or product literature)

Regimen	Notes (Dose, Frequency, Route)
Adults ≤60 kg	500 mg — IV — every 2 weeks ×3 doses, then every 4 weeks
Adults 60–100 kg	750 mg — IV — every 2 weeks ×3 doses, then every 4 weeks
Adults ≥101 kg	1000 mg — IV — every 2 weeks ×3 doses, then every 4 weeks
Subcutaneous	125 mg once weekly — SC — review after 6 months if no response

💡 Response should be assessed at 6 months → discontinue if ineffective.

🔀 Interactions

• 📋 See BNF for full list.
• ⚠️ Risk of infection ↑ with other immunosuppressants.

⚠️ Cautions

• 🧫 Screen for latent infections (e.g. TB, hepatitis) before treatment.
• 👶 Effective contraception required during therapy and until 14 weeks after last dose.
• 💉 Vaccinations: avoid live vaccines during treatment.

🚫 Contraindications

• ❌ Severe or uncontrolled infection.

💥 Side Effects

• 🤧 Respiratory: cough, URTIs.
• 💊 GI: nausea, diarrhoea, vomiting, oral ulceration, abdominal discomfort.
• 🤕 Headache, dizziness, hypertension.
• 🦠 Increased risk of infection.
• 🌸 Skin reactions and rashes.

📚 References

• BNF – Abatacept
• SmPC (electronic medicines compendium)