An elderly woman suffering from Schizophrenia is on antipsychotic medication. She developed purposeless involuntary facial and limb movements, constant chewing and puffing of cheeks. Which of the following drugs is least likely to be involved in this side effect?

The history here is suggestive of tardive dyskinesia. TARDIVE DYSKINESIA It is an EPSE of the antipsychotics Occurs months to years after staing antipsychotics Signs and symptoms: Lip smacking or chewing Tongue protrusion Choreiform hand movements Pelvic thrusting Prevalance: 5% of patients per year of antipsychotic exposure Risk factors: elderly females those with affective illness i.e., Bipolar disorder > Schizophrenia those who have had acute EPS early in treatment Clozapine is least likely associated with Tardive dyskinesia booster: Tardive dyskinesia is caused by supersensitivity of dopamine receptors. It can be treated with dopamine depletors like tetrabenazine.