The aim of this study was to review our “real-world” experience with the vesicular monoamine transporter 2 (VMAT2) inhibitors tetrabenazine (TBZ), deutetrabenazine (DTBZ), and valbenazine (VBZ) for treatment of hyperkinetic movement disorders. Access and adherence to VMAT2 inhibitors may be limited by insurance and regulatory issues, inexperience with their use by the prescribing physician, lack of efficacy, or side effects.
We performed a retrospective chart review, supplemented with a questionnaire, of all our patients treated with a VMAT2 inhibitor between January 1, 2017, and August 30, 2018.
We identified 135 patients (57.8% male) and 178 prescriptions for VMAT2 inhibitors (TBZ, n = 45 [25.3%]; DTBZ, n = 104 [58.4%]; VBZ, n = 29 [16.3%]). Tourette syndrome/tics was the most common diagnosis (n = 67 [49.6%]) for which VMAT2 inhibitors were prescribed. The VMAT2 inhibitor mean treatment durations (range; SD) and daily dosages (range; SD) were as follows: TBZ (n = 31), 5.1 months (1–19; 3.9) at 48.8 mg (12.5–112.5; 29.6); DTBZ (n = 51), 8.0 months (0.25–16.5; 4.4) at 34.4 mg (6–96; 20.7); and VBZ (n = 20), 6.0 months (0.1–16; 5.6) at 64 mg (40–160; 35.3). The VMAT2 inhibitors effectively controlled hyperkinetic movement disorders as measured by a 1- to 4-point Likert scale (1 = normal or mildly ill, 4 = severely ill) comparing illness severity before starting and while on treatment (score of 1 in 13.0%–26.7% vs 60.9%–71.9% of patients). Side effects were mild and improved or resolved following dose reduction, drug cessation, or addition of adjunctive medications.
The VMAT2 inhibitors are effective and safe in a range of hyperkinetic movement disorders but are not readily accessible by patients in the United States for indications not approved by the Food and Drug Administration.
Parkinson's Disease Center and Movement Disorders Clinic, Department of Neurology, Baylor College of Medicine, Houston, TX.
Address correspondence and reprint requests to Joseph Jankovic, MD, Department of Neurology, Baylor College of Medicine, 7200 Cambridge, Suite 9A, Houston, TX 77030; E-mail: firstname.lastname@example.org
Conflicts of Interest and Source of Funding: J.J. has received research and/or training grants from Adamas Pharmaceuticals, Inc; Allergan, Inc; Biotie Therapies; CHDI Foundation; Civitas/Acorda Therapeutics; Dystonia Coalition; Dystonia Medical Research Foundation; F. Hoffmann-La Roche Ltd; Huntington Study Group; Kyowa Haako Kirin Pharma, Inc; Medtronic Neuromodulation; Merz Pharmaceuticals; Michael J. Fox Foundation for Parkinson Research; National Institutes of Health; Neurocrine Biosciences; NeuroDerm Ltd; Parkinson's Foundation; Nuvelution; Parkinson Study Group; Pfizer Inc; Prothena Biosciences Inc; Psyadon Pharmaceuticals, Inc; Revance Therapeutics, Inc; Sangamo BioSciences, Inc; St Jude Medical; and Teva Pharmaceutical Industries Ltd. J.J. has served as a consultant or as an advisory committee member for Adamas Pharmaceuticals, Inc; Allergan, Inc; Merz Pharmaceuticals; Pfizer Inc; Prothena Biosciences; Revance Therapeutics, Inc; and Teva Pharmaceutical Industries Ltd. He has received royalties or other payments from Cambridge; Elsevier; Future Science Group; Hodder Arnold; Medlink: Neurology; Lippincott Williams and Wilkins; and Wiley-Blackwell. N.N. has no conflicts of interest to declare.
Author Contributions: N.N.: Conception, design, organization, execution, and writing of the first and subsequent drafts. J.J.: Conception, design, organization, execution, review and critique, and writing of the second and subsequent drafts.