Stuttering and Drugs

Much has been written about various drugs and stuttering. The following is not intended to be the final word on the subject. For those interested, there is much more information to be explored online, in texts, and in peer-reviewed journal articles. The information provided is only intended to provide some direction for interested persons to continue to research. A few suggested resources for researching

  • ERIC database
  • PubMed (interface for MEDLINE, National Library of Medicine's bibliographic database)
  • Scholar Google - a specialized search function that enables you to search specifically for scholarly literature, including peer-reviewed papers, theses, books, abstracts and technical reports from all broad areas of research. Features "cited by" which can lead to additional resources to explore.

Thomas David Kehoe has written a 17-page freely-available eBook Medications for Stuttering (2013)

Drug therapy FOR stuttering

From Mayo Clinic Staff: "Although some medications have been tried for stuttering, no drugs have been proved yet to help the problem." from "Treatments and drugs By Mayo Clinic Staff"

From the National Institutes of Health: "The U.S. Food and Drug Administration (FDA) has not approved any drug for the treatment of stuttering. However, some drugs that are approved to treat other health problems - such as epilepsy, anxiety, or depression - have been used to treat stuttering. These drugs often have side effects that make them difficult to use over a long period of time. In a recent study funded by the National Institute on Deafness and Other Communication Disorders (NIDCD), researchers concluded that drug therapy has been largely ineffective in controlling stuttering. Clinical trials of other possible drug treatments are currently under way." (

There is currently no "pink pill" that can "cure" stuttering. Many different drugs have been tried. Some have produced some results in alleviating some overt stuttering symptoms for some people (not all) who stutter. It is recommended that if you try any drugs to alleviate stuttering, you do so under the care of a qualified physician or psychiatrist.

  • Oliver Bloodsein and Ratner in the 6th edition of A Handbook on Stuttering, (2008), pp. 376-380 listed several drug studies that have been tried in the treatment of stuttering and report "varied results" and that "a frequent report is that the drug has more effect on the complexity or severity of stutters than on their frequency." (p. 376). Typically the drugs studied are primarily prescribed for other disorders, such as schizophrenia, Tourette syndrome, migraine headaches, high blood pressure, cardiovascular disorders, anxiety, depression, obsessive-compulsive disorder, panic, PTSD, seizure disorders. Many have unpleasant side effects including weight gain, sexual dysfunction, sedation, elevated lipid levels, triggering Type 2 diabetes, depression, etc. and people in research about their effects on stuttering at times dropped out of the studies. Among the drugs listed: haloperidol, pimozide, tiapride, risperidone, olanzapine, desipramine, clomipraine, paroxotine, fluoxetine (ed. prozac), propanolol, verapamil, clonodine, and carbazepine, and Botox. When some of the studies were completed, there were reports of relapse of stuttering. There was also mention that "over the years, favorable reports have also appeared about thiamin (Hale, 1951) and glutamic acid (Gatzmann, 1954) but information about their effectiveness is scanty." (p. 379)
  • Thiamin - Personal Correspondence, Martin Schwartz, PhD - May 2, 2015 - "In stuttering, the reciprocal inhibition between the lateral and posterior cricoarytenoids that must occur during transitions from voiced to voiceless consonants in speech is lost under conditions of stress and replaced by laryngeal spasms normally seen at the beginning and ending of the swallow reflex (adductory at the beginning; abductory at the end). These laryngeal spasms are the result of a decrease in GABA receptor function in the nucleus ambiguous, a condition that can be rectified for three out of ten young adult males who stutter if sufficient thiamin can be encouraged to cross the blood-brain barrier." (A free 92 page PDF that provides full details available at The Thiamin Protocol by Dr. Martin Schwartz
  • Pagaclone, a drug developed by Indevus Pharmaceuticals was tested first as a possible treatment for panic and anxiety disorders. However it was never commercialized. In 2006, a large-scale study began using Pagaclone to treat stuttering. Although several subjects reported varying degrees of improved fluency, the study was ended in 2011 and the drug is not currently marketed. Dr. Gerald Maguire, head of the research team studying pagaclone shared the following information, "Endo Pharmaceuticals has decided to focus on their core business of urology and pain management and will not continue the pagaclone stuttering research program. Our university will be starting our next pharmaceutical trial of asenapine in stuttering in the coming weeks. We are fortunate that Merck has funded this important double-blind trial in stuttering. The mechanism of asenapine, being a dopamine-antagonist, is more clearly defined in stuttering than the partial dopamine agonist of pagaclone." (
  • is a blog to "discuss medications taken by a patient for the speech problem stuttering. It is not medical advice, just a body of experiences from a patient trying to improve his own stuttering." The blogger shares his personal experience with Saphris (Asenapine) as well as Latuda (Lurasidone). He writes about side effects, stopped using both drugs for different reasons, and advises any attempts at medications is best also done in conjunction with speech therapy.
  • More information is available: Maguire GA, Franklin DL, Kirsten J. Asenapine for the treatment of stuttering: an analysis of three cases. Am J Psychiatry. 2011 Jun;168(6):651-2. doi: 10.1176/appi.ajp.2011.10121729.
  • Peter Reitze's StutterTalk has a series of podcasts about Medical Treatment of Stuttering including Pagaclone and Asenapine.
  • Propranolol - The above medications were prescribed to be taken on a more permanent basis I believe. One drug that some endorse as helpful on a "when needed" basis is Propranolol, sometimes called the "stage fright" medication.
  • Placebo - In some of the research studies, patients who were given a placebo also showed measurable gains in fluency.

Drugs that MAY have a side effect of causing stuttering

  • Shapiro. David Stuttering Intervention: A Collaborative Journey to Fluency Freedom (2nd edition). Pro Ed, 2011. (p. 123) lists references citing several drugs implicated as possibly causing stuttering symptoms including:
    • theophylline - a bronchodilator used for asthma
    • phenothiazine - a drug used to control psychosis and stuttering in people with schizophrenia
    • antidepressants
      • amitriptyline
      • dothiepin
      • desipramine
      • fluoxetine (prozac)
      • sertaline
    • neuroleptic agents
      • Perphenazine/desipramine combination
      • chlorpromazine/lithium combination
      • clozapine <limetrizamid - a radiopaque contrast medium</li
    • other drugs
      • theophylline
      • prochlorperazine
      • methylphenidate (Ritalin)
      • pemoline
      • levodopa
      • gabapentin
      • clorazepate
      • alprazolam
      • benzodiazepines
        • l-dopa
        • methylphenidate
      Shapiro also adds, "an ongoing concern is that most label warnings do not include information about the effects of medications on speech fluency" and encourages SLPs to inquire about any medication, especially if there was a sudden onset of any dysfluency. (p. 123)
  • Right Diagnosis "Medication causes list: The list of possible medications or substances mentioned in sources as possible causes of stuttering includes:
    • Olanzapine
    • Zyprexa
    • Zyprexa Zydis
    About medication causes: Another misdiagnosis possibility is that a particular medication or substance may be the real cause of the disease. Certain medications, chemicals, toxins or substances may possibly be underlying causes of Stuttering. Side effects of medications, or exposure to toxins, chemicals, or other substances may cause a symptom or condition. Hence, they become possible underlying causes of Stuttering but are often misdiagnosed or overlooked as a cause."
  • A case series of stuttering induced by the atypical neuroleptics olanzapine and clozapine. Olanzapine- and clozapine-induced stuttering. A case series. (PMID:15179972) Baer KJ, Haeger F, Sauer H Pharmacopsychiatry [2004, 37(3):131-134]
  • A Case of Drug Induced Stuttering by Don Mowrer and Jan Yount (1999 ISAD online conference) shared a case study of an individual with multiple sclerosis treated with multiple drugs.
  • Masand reported a drug induced stuttering resulting from desipramine. (Masand, P. (1992). Desipramine-induced oral-pharyngeal disturbances: Stuttering and jaw myoclonus (letter). Journal of Clinical Psychopharmacology, 12, 444-445.)
  • John Van Borsel, in a 2011 ASHA presentation, Acquired stuttering: differential diagnosis includes Pharmacogenic stuttering: types of drugs that can elicit stuttering:
    • Psychopharmaca
    • Anticonvulsants
    • broncho dialatator theophylline
  • The reader is referred to Alex F. Johnson, Barbara H. Jacobson's Medical Speech-Language Pathology: A Practitioner's Guide. Just finding a few pages through uncovered several drugs with possible side affects of stuttering including:
    • Sertraline (Zoloft)
    • Risperidone
    • Clozapine
    • Theophylline
    • Prochlorperazine
    • Methylphenidate
    • Pemoline
    • Levodopa
    • Alprazolam
  • The reader is also referred to Brady, John Paul MD, Drug-Induced Stuttering: A Review of the Literature, Journal of Clinical Psychopharmacology: February 1998 - Volume 18 - Issue 1 - pp 50-54

Illegal Drugs which may cause stuttering symptoms in some people

  • Ecstasy - YouTube disclosure by 20-year-old Jordy Hurdes
    Drugs which may alleviate or exacerbate overt stuttering symptoms in some people
  • Alcohol
    • "No researchers have studied the effects of alcohol on stuttering. Anecdotally, alcohol reduces stutterers' fears and anxieties (e.g., about talking to persons of the opposite sex) and so reduces stuttering. But alcohol reduces one's ability to use therapy techniques, so increases stuttering." (
    • Larry Molt, PhD, CCC-SLP/AUD responded to a question on the ISAD online conference in 1998 regarding the effect of administering alcohol. "Can any conclusions be drawn about the benefits and advantages? Molt's response "I'm not aware of any empirical research into the perceived vs. probable effects of self administration of ethanol. On the list-serves devoted to stuttering and in conversations, I have heard lots of anecdotal reports on the effects. My impressions (and these are only impressions, not research) is that a little over half of stuttering individuals report increased fluency when "under the influence", a smaller number report deleterious effects of ethanol, and an even smaller number report their fluency to be unaffected. I've also heard several theories proposed to account for this apparent discrepancy in ethanol's effects. Most commonly, theories suggest that those individuals for whom anxiety in speaking situations plays a role in eliciting stuttering may respond well to the anxyiolytic effects of alcohol, thus experiencing a fluency increase; for those who are able to maintain fluency by exerting additional motoric control strategies, the dyskinethesia associated with ethanol intoxication may disrupt their fluency. In addition, the appearance of a change in fluency (whether positive, neutral, or negative) may be a result of an altered perceptual state rather than an actual change in fluency. As these are only impressions that come from anecdotal reports, I feel that no conclusions can be drawn, especially in light of the discrepancy in results in the neuropharmacological literature between effects reported in open uncontrolled trials vs. those seen in double blind placebo controlled trials. It certainly would be interesting research to conduct, and I'm sure you might get more volunteers for this type of research than seen for many other types of research done with people who stutter! ;).(10/7/98)
  • Olanzapine
    • Olanzapine - the drug Olanzapine may cause stuttering behaviors in some peopleBaer KJ, Haeger F, Sauer H., Olanzapine- and clozapine-induced stuttering. A case series.
      Pharmacopsychiatry. 2004 May;37(3):131-4.

      ". . . . a case series of stuttering induced by the atypical neuroleptics olanzapine and clozapine. Patients receiving neuroleptic treatment were carefully screened for stuttering as a possible side effect. We have studied all patients in the outpatient department (800 per year) as well as most inpatients (1300 per year) within 3 years. Seven cases of drug-induced stuttering were observed. Six patients suffered from stuttering in association with olanzapine treatment, and one received clozapine. Stuttering arose on average 2-21 days after initiation of treatment and ceased 2-5 days after discontinuation." (abstract of article)
    • Olanzapine - the drug Olanzapine may elevate some stuttering behaviors in some people