Tetrabenazine

May be taken with or without food.

Patient with untreated or inadequately treated depression, actively suicidal, congenital long QT syndromes, history of cardiac arrhythmias; prolactin-dependent tumours (e.g. pituitary or breast cancer). Lactation. Concomitant use within 14 days of discontinuing MAOIs.

Patient with history of depression or prior suicide attempts or ideation. Patient at risk of aspiration pneumonia. May exacerbate symptoms of parkinsonism. Hepatic impairment. Pregnancy. Patient taking strong CYP2D6 inhibitors. Patient Counselling This drug may cause dizziness, sedation or somnolence, if affected, do not drive or operate machinery. Monitoring Parameters Monitor for signs or symptoms of depression or suicide ideation, parkinsonism, neuroleptic malignant syndrome, orthostatic hypotension. Perform CYP2D6 genotyping for evaluation of metabolism status (doses >50 mg/day).

Significant: Esophageal dysmotility, dysphagia and aspiration; parkinsonism (e.g. bradykinesia, hypertonia, rigidity), akathisia, restlessness, agitation, somnolence (high dose), QTc prolongation, orthostatic hypotension, hyperprolactinaemia. Cardiac disorders: Bradycardia. Gastrointestinal disorders: Dysphagia, nausea, vomiting, diarrhoea, constipation, epigastric pain, dry mouth. Nervous system disorders: Ataxia, dystonia, dizziness, amnesia, tremor, agitation. Psychiatric disorders: Anxiety, insomnia, confusion, disorientation, nervousness. Reproductive system and breast disorders: Irregular menstrual cycle.
Potentially Fatal: Neuroleptic malignant syndrome, suicidal ideation and behaviour.

May enhance the adverse effects of tetrabenazine with reserpine. Increased risk of QT prolongation with antipsychotics (e.g. chlorpromazine, thioridazine), antibiotics (e.g. gatifloxacin, moxifloxacin), or class IA and III antiarrhythmics (e.g. quinidine, procainamide, amiodarone, sotalol). May diminish the effect of levodopa. Additive sedative effects with CNS depressants (e.g. neuroleptics, hypnotics, opioids). May increase risk of dopamine depletion and parkinsonism with neuroleptic agents (e.g. haloperidol, metoclopramide, chlorpromazine). May increase risk of orthostatic hypotension with antihypertensive agents (e.g. β-blockers). Increased serum concentrations of the active metabolites of tetrabenazine (α-HTBZ, β-HTBZ) with concomitant use of strong CYP2D6 inhibitors (e.g. fluoxetine, paroxetine, quinidine).

Neuromuscular Disorder Drugs

N07XX06 - tetrabenazine ; Belongs to the class of other nervous system drugs.