Table 3.
Vesicular monoamine transporter-2 (VMAT2) inhibitors
| VMAT2 inhibitor | Half-life | Dose range | T max | CYP2D6 metabolism | %Responders (≥50% ↓AIMS) [77,82] | NNT/NNH [69,75,80] | Approved indications |
|---|---|---|---|---|---|---|---|
| TBZ | 5.5 hr | 12.5−50 mg/d in divided doses | 1−1.5 hr | Genotyping required for doses > 50 mg/d | - | - | Huntington’s chorea |
| VBZ | 20 hr | 40−80 mg QD | 4−10 hr | Consider dose reduction for poor metabolizers | 40% (80 mg) 24% (40 mg) |
5/15−500 | TD |
| DTBZ | 8.6 hr | 6−24 mg BID with food | 3−4 hr | Maximum dose = 18 mg BID in poor metabolizers | 33% (36 mg) 35% (24 mg) |
7/34−100 | Huntington’s chorea, TD |
TBZ, tetrabenazine; VBZ, valbenazine; DTBZ, deutetrabenazine; QD, once daily; BID, twice daily; TID, Thrice daily; T max, time to maximum concentration; AIMS, Abnormal Involuntary Movement Scale; NNT/NNH, number needed to treat/number needed to harm; TD, tardive dyskinesia.