How a Diuretic Might Help Treat Autism
It seems like an unlikely match, but researchers have discovered that a common diuretic, which is used to manage excessive fluid accumulation and high blood pressure, might help treat autism. News of the discovery has been published in Translational Psychiatry.
What's the link between diuretics and autism?
Investigators have pieced together various bits of data to show the relationship between diuretics and autism. Here's a brief summary of how it works.
Previous research has indicated that a brain chemical called GABA (gamma-aminobutyric acid), which inhibits neurons (brain cells) in healthy individuals, is changed in people who have autism. Experts also know that when GABA's effects are reversed, which can occur if there is a high concentration of chloride in the cells, the result is excitement rather than a calming effect, which has been seen in some people with epilepsy who are given valium.
In fact, rather than reduce seizures, the drug can aggravate them. But when researchers administered a diuretic to these patients, the seizures were reduced. What does this have to do with autism?
Valium is not prescribed to children who have autism because the drug can trigger greater agitation. This suggests high chloride concentrations are present in autism, and that a diuretic may be helpful in lowering chloride levels, as it is in epilepsy.
Therefore, a scientific team under guidance of Yehezkel Ben-Ari, founder and honorary director of INMED (Institut de Neurobiologie de la Mediterranee), INSERM, conducted a randomized, controlled trial involving 60 children (ages 3 to 11 years) who had autism or Asperger's syndrome. The children were administered either a placebo or 1 mg of a diuretic called bumetanide for three months and nothing for the fourth month.
Bumetanide is a diuretic (water pill) that belongs to class known as loop diuretics, which also includes furosemide (Lasix) and torsemide (Demadex). Loop diuretics block the kidney from retaining fluid and cause a great deal of urination, which also involves a loss of electrolytes (e.g., calcium, magnesium, potassium, and sodium).
What the study showed
All the children were monitored for four months and the severity of their autistic disorders were rated before treatment, at the end of treatment, and one month after treatment ended. Here's what the researchers observed:
- After 3 months of treatment, children who had taken bumetanide has improved significantly on a test called the Childhood Autism Rating Scale (CARS), which rates behavior. The improvement was from severe symptoms to mild to moderate symptoms.
- Children who had taken the placebo did not show any significant difference in CARS score after 3 months
- Among children who took the diuretic, there was a 77 percent improved on the Clinical Global Impression (CGI) test, which rates severity of illness and changes over time and effectiveness of medication, compared with 33 percent among those who took placebo.
- Children who took the diuretic showed a modest improvement on the Autism Diagnostic Observation Schedule--Generic (ADOS-G) indicator. This is a standardized assessment tool of communication, social interaction, play, and imaginative use of materials for children believed to have autism spectrum disorder.
- Side effects were limited. Bumetanide causes a loss of potassium, and six children required supplementation with potassium and one additional child was withdrawn from the study because of abnormally low potassium.
Aside from an earlier and smaller (5 patients) open-label pilot study, this effort was the first to administer the diuretic bumetanide to individuals with autism. As the authors noted, even though the diuretic is not a cure for autism, it did result in an improvement in more than three-quarters of children treated, indicating there is enough interest to do further research.
Lemonnier E et al. A randomised controlled trial of bumetanide in the treatment of autism in children. Translational Psychiatry 2012 Dec 11; 2:e202