Peripheral vasodilation resulting to small increase in heart rate, palpitations & tremor. Headache, hypersensitivity reactions (angioedema, urticaria, hypotension & collapse), bronchospasm, cough, mouth & throat irritation, hypokalaemia, muscle cramps, hyperactivity, restlessness, dizziness & cardiac arrhythmias including atrial fibrillation, supraventricular tachycardia & extrasystoles, myocardial ischaemia.