Table 2.
Most frequently prescribed drugs for chorea in Huntington’s disease (HD)
| Drug | Adverse effects | Contraindications | Drug interactions |
|---|---|---|---|
| Tetrabenazine | Depression, somnolence, parkinsonism, insomnia, akathisia, anxiety, nausea | Active depression or suicidal ideation, psychosis, impaired hepatic function, concomitant use of MAO-inhibitors | Reduce tetrabenazine dose with concomitant use of fluoxetine and paroxetine |
| Olanzapine | Sedation, weight gain, dry mouth, Parkinsonism | None specific | Drugs that induce CYP1A2 enzymes (carbamazepine, omeprazole, rifampin) may reduce olanzapine plasma levels. CYP1A2 inhibitors (estrogens, fluvoxamine) may increase plasma levels |
| Risperidone | Parkinsonism, akathisia, sedation, hyperprolactinemia | None specific | Drugs that induce CYP3A4 enzymes (carbamazepine, phenobarbital, phenytoin) may reduce risperidone plasma levels. Fluoxetine and paroxetine can increase plasma concentration |
| Tiapridea | Sedation, parkinsonism | Prolactin-dependent tumors, history of QT-prolongation | Concomitant use of levodopa or other dopamine agonists is contraindicated. Sedative effect of tiapride can be increased in combination with antidepressants, benzodiazepines and opioids |
| Quetiapine | Weight gain, dry mouth, parkinsonism, sedation, akathisia | History of QT-prolongation, neutropenia | CYP3A4 inhibitors (clarithromycin, erythromycin, ketoconazole) can increase quetiapine plasma levels. Increase quetiapine dose with concomitant use of CYP3A4 enzyme inducers (carbamazepine, rifampin, phenytoin, glucocorticoids) |
| Aripiprazole | Sedation, parkinsonism, akathisia, cardiac arrhythmias | None specific | CYP2A4 or CYP2D6 inhibitors (ketoconazole, quinidine, fluoxetine, paroxetine) can inhibit aripiprazole elimination and cause increased blood levels. Concomitant use of serotonergic drugs can increase risk of serotonergic syndrome |
| Clozapine | Orthostatic hypotension, sedation, weight gain, increased seizure risk, agranulocytosis | Myeloproliferative disorders, history of agranulocytosis, uncontrolled epilepsy, paralytic ileus, or hepatic dysfunction | Reduce dose when combining with fluvoxamine and paroxetine. Drugs that induce cytochrome P450 enzymes may decrease clozapine plasma levels |
| Haloperidol | Tardive dyskinesia, sedation, parkinsonism, akathisia, tachycardia | Coma, history of QT prolongation or other clinical significant cardiac diseases | CYP3A4 or CYP2D6 isoenzymes inhibitors (venlafaxine, fluvoxamine, sertraline, buspirone, and alprazolam) Rifampin or carbamazepine can reduce haloperidol plasma levels. |
| Sulpiride | Sedation, parkinsonism, hyperprolactinemia, akathisia, weight gain | Pheochromocytoma, prolactin-dependent tumors (such as pituitary tumors, breast cancer) | Concomitant use of levodopa or other dopamine agonists is contraindicated |
| Amantadine | Insomnia, hallucinations, anxiety, agitation, cardiac arrhythmias, dry mouth | Refractory epilepsy, psychosis, acute glaucoma | Adverse effects of anticholinergic drugs may be increased with concomitant use of amantadine. Quinine can reduce the renal clearance of amantadine |
Drugs listed in this table are the most commonly prescribed drugs for the treatment of chorea based on international surveys among HD experts and registered HD patients (Priller et al. [11], Orth et al. [25], Burgunder et al. [10]). Most commonly reported adverse effects, contraindications, and drug interactions are described (Brown et al. [64], Videnovic [59])
aTiapride is only available in European countries