Possible Therapy for Polio-Like Illness Is Not Effective
In new research on a potential treatment for acute flaccid myelitis, the antidepressant fluoxetine showed no efficacy. The study, published in the November 9, 2018 online issue of Neurology, contradicted suggestions that fluoxetine could be an effective therapy for the polio-like illness.
Previous research showed that enterovirus D68 (EV-D68) might cause the condition, which causes sudden muscle weakness in the arms, legs, or neck and difficulty swallowing and speaking. In those studies, fluoxetine had antiviral effects against EV-D68, but the trial published in Neurology suggests that the drug is ineffective.
“The lack of an efficacy signal for the treatments for acute flaccid myelitis evaluated in this study emphasizes the need for development and prospective evaluation of more effective treatment and prevention strategies for this potentially devastating condition,” said study author Kevin Messacar, MD, of Children’s Hospital Colorado in Aurora.
For the retrospective study, investigators funded by the National Institutes of Health (NIH) examined 56 children from 2½ to 9 years of age diagnosed with acute flaccid myelitis in 2015-2016 at 12 medical centers in the U.S. Before developing the illness, 91% of the children were sick—71% had fever and 73% had respiratory symptoms. Muscle weakness appeared an average of 8.5 days after the start of illness.
A group of 28 children in the study, who received more than 1 dose of fluoxetine, were compared to 26 children who did not receive the drug, including 2 who had only 1 dose.
Children’s arm and leg muscle strength was recorded as the measure of efficacy. At the first exams, there was no difference in strength between the 2 groups; 7 months later, the children who had taken fluoxetine had lower strength scores than those who did not receive the drug.
On a scale of 0 to 20 for muscle strength for all limbs, the strength scores of children who received fluoxetine worsened by 0.2 points, while those who did not receive the drug improved by 2.5 points.
Messacar noted that the study had several limitations: It looked back in time; patients were not chosen at random to receive the treatment; and doctors, patients and their families were aware that the children were receiving the drug. Also, the small number of patients may make it difficult to draw definite conclusions.