Ans. is 'a' i.e., DantroleneNeurological side effects of Neuroleptic DrugsReactionFeaturesTime of Maximal RiskProposedMechanismTreatmentAcute dystoniaSpasm of muscles of tongue, face, neck, back, may mimic seizures; not hysteria1 to 5 daysUnknownAntiparkinsonian ages are diagnostic and curativeAkathisiaMotor restlessness; not anxiety or "agitation"5 to 60 daysUnknownReduce dose or change drug; antiparkinsonian agents, benzodiazepines or propranolol may helpParkinsonismBradykinesia, rigidity, variable tremor, mask facies, shuffling gait5 to 30 days; can recur even after a single doseAntagonism of dopamineAntiparkinsonian agents helpfulNeurolepticmalignantsyndromeCatatonia, stupor, fever unstable blood pressure myoglobinemia; can be fatalWeeks; can persist for days after stopping neurolepticAntagonism of dopamine may contributeStop neuroleptic immediately; dantrolene orbromocriptine may help; antiparkinsonism agents not effectivePerioral tremor"rabbitsyndrome"Perioral tremor (may be a late variant of parkinsonism)After months or years of treatmentUnknownAntiparkinsonian agents often helpTardivedyskinesiaOral-facial dyskinesia; widespread choreo- athetosis or dystoniaAfter months or years of treatment (worse on withdrawal)Excess function of dopamine hypothesizedPrevention crucial; treatment unsatisfactory