Nausea, vomiting, epigastric pain, diarrhea. Headache, irritability, insomnia, muscle twitching, clonic & tonic generalized convulsions. Palpitation, tachycardia, extrasystoles, flushing, hypotension, ventricular arrhythmias. Tachypnea, potentiation of diuresis, alopecia, rash.