Adult dose and durationIntravenous infusion, dosed by body weight, with a three-dose induction. SmPC verbatim, for fistulising, active Crohn's disease: "5 mg/kg given as an intravenous infusion followed by additional 5 mg/kg infusions at 2 and 6 weeks after the first infusion." Maintenance verbatim: "Additional infusions of 5 mg/kg every 8 weeks". - Stopped after three doses if nothing has changed. SmPC verbatim: "If a patient does not respond after 3 doses, no additional treatment with infliximab should be given."
Paediatric doseAge restriction: minimum 72 months
(The paediatric licence is Crohn's disease from 6 years, not fistulising disease specifically. SmPC verbatim: "Remsima is indicated for treatment of severe, active Crohn's disease in children and adolescents aged 6 to 17 years, who have not responded to conventional therapy", at "5 mg/kg given as an intravenous infusion followed by additional 5 mg/kg infusion doses at 2 and 6 weeks after the first infusion, then every 8 weeks thereafter." A child with a perianal fistula belongs with paediatric gastroenterology and surgery together.)
Dose sourceRemsima 100 mg powder for concentrate for solution for infusion (infliximab) SmPC sections 4.1, 4.2, 4.3 and 4.4 (eMC product 3709)
WhyTwo claims, both from documents that were opened, and the boundary between them matters. The disease article names the drug and rules out the obvious alternatives, verbatim: "Aminosalicylates and corticosteroids, which are commonly used first-line agents for intestinal Crohn disease, are ineffective for perianal fistulizing disease. Biological agents such as anti-tumor necrosis factor alpha drugs (infliximab) and monoclonal antibodies like adalimumab and ustekinumab remain the cornerstone of medical management." The SmPC's indication section names the same disease, verbatim: "treatment of fistulising, active Crohn's disease, in adult patients who have not responded despite a full and adequate course of therapy with conventional treatment (including antibiotics, drainage and immunosuppressive therapy)." The dose belongs to Crohn's-related perianal fistula only. A cryptoglandular fistula with no inflammatory bowel disease behind it is a surgical problem, and the article is explicit that "The management of anorectal fistula is almost always surgical". Egypt registers one infliximab product, REMICADE 100 mg powder for intravenous infusion at roughly 5,900 EGP a vial, and a course is several vials per infusion at adult body weights.
Cautions- RED FLAG - tuberculosis is excluded before the first infusion, not after it. SmPC verbatim: "Before starting treatment with infliximab, all patients must be evaluated for both active and inactive ('latent') tuberculosis." and "Appropriate screening tests, (e.g. tuberculin skin test, chest X-ray, and/or Interferon Gamma Release Assay), should be performed in all patients". The SmPC also warns that "in the majority of these reports tuberculosis was extrapulmonary". Latent tuberculosis is common in Egypt, so this is a real gate rather than a formality.
- Infection risk runs for months after the last infusion. SmPC verbatim: "Patients must be monitored closely for infections including tuberculosis before, during and after treatment with infliximab. Because the elimination of infliximab may take up to six months, monitoring should be continued throughout this period. Further treatment with infliximab must not be given if a patient develops a serious infection or sepsis." A blunted fever is part of the hazard - "suppression of TNF may mask symptoms of infection such as fever".
- Contraindicated outright in some patients. SmPC verbatim: "Patients with tuberculosis or other severe infections such as sepsis, abscesses, and opportunistic infections" and "Patients with moderate or severe heart failure (NYHA class III/IV)".
- An intravenous hospital drug, not a prescription pad drug. SmPC verbatim: "Remsima infusions should be administered by qualified healthcare professionals trained to detect any infusion-related issues." and "Infliximab has been associated with acute infusion-related reactions, including anaphylactic shock, and delayed hypersensitivity reactions".
- Drain the abscess first. The disease article has biologics frequently paired with an antibiotic - ciprofloxacin and metronidazole are the ones it names - where an abscess is present at the same time. An undrained perianal abscess under a TNF blocker is the worst of both.