LAS VEGAS – There currently is no Food and Drug Administration–approved medication for the symptomatic treatment of stuttering, but current evidence suggests that second-generation antipsychotics risperidone, olanzapine, and asenapine are beneficial, according to Gerald A. Maguire, MD.
At an annual psychopharmacology update held by the Nevada Psychiatric Association, Dr. Maguire, who is a stutterer himself, said current clinical trials in adults with childhood onset fluency disorder support the dopamine hypothesis of stuttering, where abnormal elevated cerebral dopaminergic activity is implicated.
“Individuals with stuttering who are given dopamine agonists show worsening of stuttering symptoms,” said Dr. Maguire, chair of psychiatry and neuroscience at the University of California, Riverside. “Striatal hypometabolism documented by PET imaging may be explained by the measured increased levels of presynaptic dopamine in people who stutter as compared to controls, as dopamine is an inhibitor of striatal metabolism.”Older studies found haloperidol to be effective for the treatment of stuttering, but long-term patient outlook is poor because of side effects such as sedation and sexual dysfunction. In a study led by Dr. Maguire, risperidone at a dose of 0.5-2 mg daily for 6 weeks was shown to decrease the percentage of syllables stuttered, time stuttered as a percentage of total time speaking, and overall stuttering severity, compared with placebo (J Clin Psychopharmacol. 2000;20[4]:479-82). A more recent study he also led found that olanzapine at a dose of 2.5-5 mg daily for 90 days showed a significant reduction in symptoms as measured by multiple tools, including the Stuttering Severity Instrument–Third Edition, the Clinical Global Impression scale, and the subject-rated self-assessment of stuttering scale (Ann Clin Psychiatry. 2004;16[2]:63-7).
Dr. Maguire, also associate dean of graduate medical education at the University of California, Riverside medical school, added that findings from several case reports suggest that asenapine and aripiprazole also are effective for managing stuttering symptoms. “Further studies of these drugs are warranted given better side-effect profiles as compared to other second-generation antipsychotics,” he said. There are ongoing investigations of other medications for the treatment of stuttering, including ecopipam, a D-1 dopamine receptor antagonist. An open-label study of ecopipam in adults who stutter is currently under way.
Dr. Maguire disclosed that he has received grant or research support from Intracellular, the Stanley Foundation, and Sunovion. He also is a consultant for Lundbeck, Otsuka, Sunovion, Takeda, and is a member of the speakers’ bureau or has received honoraria from Acadia, Lundbeck, Otsuka, Sunovion, Takeda, and Vanda.