title: Immunomodulatory drugs (natalizumab), worsening of multiple sclerosis, rebound effect and similitude.
abstract: BACKGROUND
  Homeopathic treatment is based on the principle of similitude ('like cures like') administering to sick individuals substances that cause similar symptoms in healthy individuals, employing the paradoxical or biphasic action of the organism as therapeutic response. This homeostatic, vital or secondary action of the organism is scientifically explained by the rebound effect of drugs, resulting in worsening of symptoms after enantiopathic treatment withdrawal. Natalizumab reduces relapses in patients with active multiple sclerosis (MS), but recent studies report severe worsening of MS after suspension of treatment, as a consequence of the rebound effect.
  
  
  METHODS
  Extending this source of evidence, this work reviews research that demonstrates secondary worsening of MS after discontinuation of natalizumab, a human monoclonal antibody that suppresses the disease inflammatory activity as primary action.
  
  
  RESULTS
  Several studies refer to the immune reconstitution inflammatory syndrome (IRIS) as a plausible explanation of reactivation of MS after withdrawal of natalizumab: a rebound effect or secondary action of the organism in response to the primary immunosuppression caused by the drug.
  
  
  CONCLUSIONS
  Relapses of MS after discontinuation of natalizumab treatment indicate rebound of disease activity, supporting the homeopathic principle and warning healthcare professionals about this serious iatrogenic event.
authors.affiliation: Department of Internal Medicine, Faculty of Medicine, University of São Paulo, São Paulo, Brazil. marcus@homeozulian.med.br
authors.forename: Marcus Zulian
authors.initials: MZ
authors.lastname: Teixeira
mesh_terms: D061067:Antibodies, Monoclonal, Humanized / Q000008:administration & dosage / Q000009:adverse effects*; D006705:Homeopathy / Q000009:adverse effects*; D006801:Humans; D007155:Immunologic Factors / Q000008:administration & dosage / Q000009:adverse effects*; D039441:Integrin alpha4 / Q000276:immunology; D009103:Multiple Sclerosis / Q000188:drug therapy*; D000069442:Natalizumab
chemical_list: D061067:Antibodies, Monoclonal, Humanized; D007155:Immunologic Factors; D000069442:Natalizumab; D039441:Integrin alpha4
keywords: Homeopathy; Immune reconstitution inflammatory syndrome; Law of similars; Multiple sclerosis; Natalizumab; Paradoxical reaction; Pharmacodynamic action of homeopathic remedy; Rebound effect