Infliximab

1. See Also
   1. Etanercept (Enbrel)
   2. Adalimumab (Humira)
2. Indications
   1. Moderate to severe refractory Crohn's Disease
   2. Refractory Rheumatoid Arthritis
      1. Added to Methotrexate or with other agents
3. Contraindications
   1. Histoplasmosis
   2. Coccidioidomycosis
   3. Tuberculosis
4. Mechanism
   1. Anti-TNF alpha Monoclonal Antibody
      1. Monoclonal Antibody binds Tumor necrosis factor alpha
5. Pharmacokinetics
   1. Half life of 5 mg/kg single dose: 10 days
6. Disadvantages
   1. Cost: $2380/dose (cost to pharmacist)
7. Dose: Crohn's Disease
   1. Initial: 5 mg/kg IV infusion over 2 hours
   2. Repeat at 2 weeks and 6 weeks for fistulas
8. Dose: Rheumatoid Arthritis
   1. Initial: 3 mg/kg IV at 0 weeks, 2 weeks and 6 weeks
   2. Maintenance: 3 mg/kg IV every 8 weeks (6x/year)
   3. Dosing range is 3-10 mg/kg (typically higher doses than 3 mg needed with longterm use)
9. Efficacy: Crohn's Disease
   1. Significant response to remission even with fistulas
   2. Relapse may occur after 3 months
10. Adverse effects
    1. Safety of repeated use unknown
    2. Serum Sickness
    3. Lymphoma
    4. Opportunistic Infection
       1. Associated with granulomatous infection
          1. Tuberculosis
          2. Histoplasmosis
       2. Higher risk of infection than with Etanercept
          1. Wallis (2004) Clin Infect Dis 38:1261-5
11. Drug Interactions
    1. Acetaminophen
    2. Benadryl
    3. Solu-Medrol
    4. Epinephrine
12. References
    1. (1999) Med Lett Drugs Ther 41(1047): 19-20
    2. Maini (2000) Lancet