What is the appropriate infliximab (5 mg/kg intravenous) dosing schedule, pre‑infusion screening, premedication, monitoring, and safety precautions for a patient with moderate‑to‑severe plaque psoriasis?

Infliximab Infusion Protocol for Moderate-to-Severe Plaque Psoriasis

Dosing Schedule

Infliximab should be administered at 5 mg/kg intravenously at weeks 0,2, and 6 for induction, followed by maintenance dosing every 8 weeks thereafter. 1, 2

• For patients with inadequate response, consider increasing the dose to 10 mg/kg or shortening the maintenance interval to as frequently as every 4 weeks, though higher doses carry increased infection risk 1, 2
• Continuous maintenance therapy every 8 weeks is superior to intermittent (as-needed) therapy and should be planned as long-term treatment from the outset 3
• Patients typically show response by week 2, making infliximab the preferred choice when rapid disease control is needed 4
• Avoid intermittent therapy patterns, as they significantly increase the risk of serious infusion reactions (4% vs <1% with continuous therapy) 3

Pre-Infusion Screening

All patients must be evaluated for active tuberculosis and tested for latent TB infection prior to initiating infliximab and periodically during therapy. 2

• Screen for tuberculosis is essential; provide prophylactic treatment if latent TB is detected before starting infliximab 5
• Evaluate for hepatitis B virus infection, as reactivation can occur 1
• Assess for history of congestive heart failure, demyelinating disorders, and other autoimmune conditions 2
• Review for any active infections or immunosuppressive conditions 2

Premedication

Premedication may be administered at the physician's discretion and can include antihistamines (H1 ± H2 blockers), acetaminophen, and/or corticosteroids. 2

• The combination of acetaminophen, hydroxyzine, ranitidine, and methylprednisolone before infusion can reduce infusion reactions and prolong drug survival 1
• Approximately 20% of patients experience infusion reactions compared to 10% with placebo 2
• Anaphylaxis can occur at any time during infusion; appropriate personnel and medications must be available 2

Infusion Administration

The infusion should be prepared using aseptic technique by trained medical personnel under physician supervision. 2

• Reconstitute each 100 mg vial with 10 mL Sterile Water for Injection using a 21-gauge or smaller needle 2
• Direct the water stream to the glass wall of the vial, then gently swirl (do not shake) to dissolve 2
• Allow reconstituted solution to stand for 5 minutes; final concentration is 10 mg/mL 2
• Infusion reactions may include flu-like symptoms, headache, dyspnea, hypotension, fever, chills, gastrointestinal symptoms, and rashes 2

Monitoring During Infusion

For mild to moderate infusion reactions, slow or suspend the infusion, then reinitiate at a lower rate with therapeutic administration of antihistamines, acetaminophen, and/or corticosteroids. 2

• Discontinue infliximab immediately for severe infusion-related hypersensitivity reactions 2
• Patients who cannot tolerate infusion despite interventions should be discontinued from further treatment 2
• Management of severe reactions should be dictated by the signs and symptoms of the reaction 2

Ongoing Monitoring

Patients should be monitored for infections, malignancies, and other adverse effects at each treatment visit. 2

• Instruct patients to report any signs of infection, including symptoms of tuberculosis reactivation 2
• Monitor for signs of cytopenia (bruising, bleeding, persistent fever) 1
• Assess for new or worsening heart disease, neurological symptoms, or autoimmune disorders 2
• Consider that body mass index inversely correlates with drug levels; higher BMI patients may require dose adjustments 6
• Evaluate for development of antibodies to infliximab, which can lead to loss of clinical response and increased infusion reactions 1

Safety Precautions

Infliximab suppresses the immune system and increases the risk of serious infections, lymphoma, and other malignancies. 2

• The risk of serious infections increases at higher doses (>5 mg/kg) 2
• Patients should be closely monitored with regular follow-up visits 2
• Store unopened vials refrigerated at 2°C to 8°C; may be stored at room temperature up to 30°C for up to 6 months but cannot be returned to refrigeration 2
• Infliximab can be used with or without methotrexate; methotrexate reduces immunogenicity of infliximab 1

Expected Efficacy

At week 10, approximately 75-80% of patients achieve PASI 75 response with 5 mg/kg infliximab. 1, 5

• PASI 90 is achieved by 37-45% of patients at week 10 1
• Response is maintained through week 50 with continuous every-8-week dosing 2
• Infliximab is effective for plaque psoriasis, nail psoriasis, palmoplantar psoriasis, and psoriatic arthritis 1, 7