Table 2.
Class | Names | Mechanism(s) of action | Most frequent side effects |
---|---|---|---|
Anticholinergic [84] | trihexyphenidyl benztropine |
block acetylcholine receptors | dry mouth, constipation, blurred vision, mild memory impairment |
Benzodiazepine [63] | clonazepam lorazepam diazepam |
potentiate the effects of GABA on GABAA receptors | drowsiness, disequilibrium |
GABAB receptor agonist [90] | baclofen | stimulates GABAB receptors | drowsiness, disequilibrium, weakness |
Dopamine precursor [91] | levodopa | converted to dopamine | nausea |
Dopamine receptor agonist [92] | bromocriptine | stimulates D2 dopamine receptors, 5-HT2 antagonist | nausea, lightheadness, drowsiness |
Neuroleptic [93] | pimozide haloperidol |
blocks dopamine receptors (D2 > D3 > D1 & D4) |
tardive dyskinesias** |
Monoamine depleter [93] | tetrabenazine | inhibits monoamine transporters in the brain | depression, drowsiness, Parkinsonism |
Anticonvulsant [81] | levetiracetam | binds to the synaptic vesicle protein SV2A | irritability, headaches |
Imidazopyridine [94] | zolpidem | binds to the benzodiazepine receptor 1 | drowsiness, dizziness, headache |
Atypical antipsychotic [95] | clozapine | blocks dopamine receptors (D4 ≫D1, D2, D3, & D5), partial 5-HT1A agonist, cholinergic and histaminergic antagonist | constipation, sedation, agranulocytosis |
Serotonin receptor antagonist [96] | cyproheptadine | 5-HT2 antagonist, antihistaminic | drowsiness, nausea |
Antiarrhythmic agent [97] | mexiletine | inhibits inward sodium currents | nausea, dizziness, tremor |
None of these medications are FDA approved treatments for blepharospasm
Tardive dyskinesias may be a permanent side effect