Review of: Ghaleiha A et al, J Child Adolesc Psychopharmacol 2016;26(9): 784–791.

The only medication treatments approved for autism spectrum disorder (ASD) are the antipsychotics risperidone and aripiprazole, which are indicated specifically to manage irritability associated with ASD. There’s been some interest in minocycline, which is a second-generation tetracycline antibiotic, for various psychiatric disorders, including depression, schizophrenia, and Parkinson’s disease. Why would an antibiotic be helpful in psychiatry? Minocycline crosses the blood-brain barrier and may have neuroprotective effects. A recent study tested whether minocycline might be useful as an adjunct to risperidone for ASD.

Ghaleiha and colleagues conducted a 10-week, randomized, double-blind, placebo-controlled trial with 46 children with ASD, aged 4–12. Participants were randomly assigned to receive either risperidone plus minocycline 50 mg twice a day, or risperidone plus placebo. Risperidone was titrated up to 1 mg or 2 mg a day based on the body weight. Each child was evaluated at baseline, week 5, and week 10. Based on the Aberrant Behavior Checklist scale, patients assigned to minocycline plus risperidone showed significantly more improvement on measures of irritability and hyperactivity/noncompliance. There were no differences between the groups in the other measures of ASD, such as lethargy/social withdrawal, stereotypic behavior, inappropriate speech, and side effect profiles. The minocycline group showed at least partial response (> 25% irritability reduction) or complete response (> 50% irritability reduction) when compared to placebo’s 65.5% at the end of the study. No serious side effects were reported, and frequency of side effects were comparable between the groups.

CCPR’s Take
Adding minocycline 50 mg twice a day to risperidone may help with symptoms of irritability and hyperactivity. And though not tested in this trial, adding the antibiotic might theoretically allow us to use a lower dose of risperidone, leading to potentially fewer side effects. The study was small and needs replication, but given the good tolerability of minocycline, this is a strategy you might want to try for some of your kids with ASD.