Treatment of Pediatric Movement Disorders
Medication: Tetrabenazine and Reserpine
Tetrabenazine (Nitoman®, Xenazine®) and reserpine act by depleting the supply of dopamine, norepinephrine, and serotonin in nerve terminals, thereby decreasing the amount available for release. Tetrabenazine may also block both D1 and D2 receptors. These medicines are sometimes useful in dystonia, but reserved for severe cases due to the high rate of side effects. Tetrabenazine has also been reported to be useful in chorea and tic disorders. In addition, tetrabenazine has many of the beneficial effects of neuroleptics, without causing tardive dyskinesia. Both tetrabenazine and reserpine may cause parkinsonism; signs of parkinsonism must be carefully watched for, since mild parkinsonian bradykinesia may be difficult to detect in a child with generalized dystonia. Both medications may cause a decrease in blood pressure (hypotension). This effect is particularly profound with reserpine; in children, this medication must usually be started while in the hospital under frequent blood pressure monitoring. Tetrabenazine may cause drowsiness and, in rare cases, neuroleptic malignant syndrome.