Side effects of minocycline treatment in patients with fragile X syndrome and exploration of outcome measures

Am J Intellect Dev Disabil. 2010 Sep;115(5):433-43. doi: 10.1352/1944-7558-115.5.433.


Minocycline can rescue the dendritic spine and synaptic structural abnormalities in the fragile X knock-out mouse. This is a review and preliminary survey to document side effects and potential outcome measures for minocycline use in the treatment of individuals with fragile X syndrome. We surveyed 50 patients with fragile X syndrome who received minocycline for at least 2 weeks and found that the most common reported side effect is gastrointestinal difficulty, including loss of appetite. The families reported an improvement in language and behavioral areas. Outcome measures in the design of future randomized clinical trials should include both behavioral and language measures. As with any other treatments, we emphasize that randomized clinical trials are needed to determine the efficacy of minocycline in fragile X syndrome.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Adolescent
  • Anti-Bacterial Agents / adverse effects*
  • Anti-Bacterial Agents / therapeutic use
  • Child
  • Child Behavior Disorders / diagnosis
  • Child Behavior Disorders / drug therapy
  • Child, Preschool
  • Female
  • Follow-Up Studies
  • Fragile X Syndrome / diagnosis
  • Fragile X Syndrome / drug therapy*
  • Humans
  • Infant
  • Language Development Disorders / diagnosis
  • Language Development Disorders / drug therapy
  • Male
  • Minocycline / adverse effects*
  • Minocycline / therapeutic use
  • Neuroprotective Agents / adverse effects*
  • Neuroprotective Agents / therapeutic use
  • Randomized Controlled Trials as Topic
  • Young Adult


  • Anti-Bacterial Agents
  • Neuroprotective Agents
  • Minocycline