A 60-year-old woman with longstanding schizophrenia has disabling orofacial choreoathetoid movements after years of antipsychotic therapy. Which drug, approved for tardive dyskinesia, acts by reversibly inhibiting vesicular monoamine transporter 2 (VMAT2)?
- A Pramipexole
- B Valbenazine ✓
- C Rasagiline
- D Entacapone
Correct answer: B. Valbenazine
Explanation
Valbenazine and its active metabolite are reversible inhibitors of VMAT2, reducing packaging of dopamine into synaptic vesicles and decreasing dopamine release, which improves involuntary movements of tardive dyskinesia. Deutetrabenazine shares this mechanism. Pramipexole is a dopamine agonist, rasagiline an MAO-A inhibitor, and entacapone a COMT inhibitor; all three are antiparkinsonian drugs and would be expected to worsen dyskinesias. Traditional teaching favoured tetrabenazine, another VMAT2 inhibitor, for the same indication.
Reference: Katzung Basic and Clinical Pharmacology, 15th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.