All of the following drugs can cause neuroleptic malignant syndrome except:

Malignant neuroleptic syndrome It occurs rarely with high doses of potent agents; the patient develops marked rigidity, immobility, tremor, fever, semiconsciousness, fluctuating BP and hea rate; myoglobin may be present in blood-lasts 5-10 days after drug withdrawal and may be fatal. The neuroleptic must be stopped promptly and symptomatic treatment given. Though, antidopaminergic action of the neuroleptic may be involved in the causation of this syndrome; anticholinergics are of no help. Intravenous dantrolene may benefit. Bromocriptine in large doses has been found useful. Ref KD Tripati 8th ed.