Peripheral adverse effects levidopa

Anorexia, nausea, and vomiting occur because of stimulation of the chemoreceptor trigger zone of the medulla. Tachycardia and ventricular extrasystoles result from dopaminergic action on the heart. Hypotension may also develop. Adrenergic action on the iris causes mydriasis, and, in some individuals, blood dyscrasias and a positive reaction to the Coombs test are seen. Saliva and urine are a brownish color because of the melanin pigment produced from catecholamine oxidation.