Table 1.
Oral drugs used in the treatment of dystonia.
| Dose | Adverse effects [De Boer et al. 2012] | |
|---|---|---|
|
Commonly used Anticholinergics | ||
| Trihexyphenidyl | Gradually increase to 12 mg in 4 weeks, up to 60–100 mg q.d. [Jankovic, 2006] | Dry mouth, blurred vision, constipation, urinary retention, confusion, memory loss, hallucinations, behavioural changes |
| GABA-mimetics | ||
| Baclofen | Gradually increase to 30 mg in 1 week, up to 40–180 mg q.d. [Greene, 1992] | Lethargy, dizziness, gastrointestinal complaints, urinary frequency |
| Clonazepam | Gradually increase in 2–4 weeks, up to 1.5–12 mg q.d. [Greene et al. 1988a] | Drowsiness, dizziness, ataxia, confusion |
| Dopaminergic agents | ||
| Levodopa (DRD) | Start with 100 mg levodopa + 25 mg decarboxylase inhibitor, increase up to 1000 mg. When after 1 month no effect, stop and reconsider diagnosis DRD [Jankovic, 2006] | Dyskinesia, sleepiness, orthostatic hypotension, nausea, gastrointestinal symptoms, hallucinations, behavioural changes |
| Rarely used | ||
| Tetrabenazine | Gradually increase in 7 weeks, up to 100 mg q.d., starting with 12.5 mg [Kenney et al. 2007] | Drowsiness, Parkinsonism, depression, akathisia |
| Apomorphine | 10–50 mg continuously SC, sometimes in combination with levodopa / lisuride [Langkafel et al. 1991] | Sedation, confusion, hallucinations, skin irritation |
| Lisuride | 0.4 to 5–12 mg q.d [Bassi et al. 1982; Quinn et al. 1985] | Dyskinesia, sleepiness, orthostatic hypotension, nausea, gastrointestinal symptoms, hallucinations, behavioural changes |
| Bromocriptine | 18–150 mg/day (mean 72.5 mg) [Stahl and Berger, 1981; Newman et al. 1985] | Nausea, vomiting, constipation, headache, sedation, dizziness |
| Clozapine | Gradually increase by 12.5–25 mg q.d., up to 300 mg q.d. [Karp et al. 1999] | Sleepiness, tachycardia, dizziness, constipation, granulocytopenia |
| Olanzapine | Gradually increase by 2.5 mg q.d., up to 15 mg q.d. [Lin and Chang, 2004] | Sleepiness, tachycardia, dizziness, constipation, granulocytopenia, weight gain |
| Tiapride | Start with 100 mg t.i.d. IV, continue with equal oral dose, up to 500 mg q.d. [Arlazoroff et al. 1991] | Hyperprolactinemia, sleepiness, dizziness, behavioural changes, headache, Parkinsonism |
| Risperidone | Start with 2 mg q.d., increase daily up to 8 mg q.d. [Wohrle et al. 2003] | Depression, weight gain, Parkinsonism, headache, insomnia |
| Orphenadrine | NA [Jacob, 1962] | Dry mouth, blurred vision, constipation, urinary retention, confusion, memory loss, hallucinations, behavioural changes |
| Haloperidol | Gradually increase by 0.5 mg q.d. to 1.5–14 mg q.d. [Gilbert, 1972] | Emotional deprivation, dystonia, Parkinsonism |
| Diphenidramine | Start with 50 mg q.i.d., increase up to 400 mg q.d. [Truong et al. 1995] | Somnolence, dizziness, dry mouth, tachycardia, urinary retention, constipation |
| Mexiletine | Start with 200 mg q.d., increase up to 450–1200 mg q.d. [Ohara et al. 1998; Lucetti et al. 2000] | Dizziness, heartburn, nausea, nervousness, trembling, unsteadiness |
| Chlorzoxazone | NA [Strang, 1967] | Dizziness, malaise, nausea, vomiting, liver dysfunction |
| Carbamazepine | Gradually increase up to 200–1200 mg q.d., starting with 200 mg q.d. [Geller et al. 1976] | Leukopenia, dizziness, ataxia, sleepiness, nausea, vomiting, skin rash |
| Levetiracetam | Gradually increase up to 1000 mg b.i.d. / 1500 mg t.i.d., starting with 500 mg q.d. [Zesiewicz et al. 2004; Sullivan et al. 2005; Yardimci et al. 2006] | Asthenia, sleepiness, ataxia, behavioural changes, depression, amnesia |
b.i.d., twice a day; DRD, dopa-responsive dystonia; IV, intravenously; NA, not available; q.d., per day; q.i.d., four times a day; SC, subcutaneous; t.i.d., three times a day.