From the cardiovascular system: ECG change (ST depression, QT interval prolongation), tachycardia, extrasystole, lability of blood pressure, sensations of hot flashes.
From the central nervous system: sleep disturbances (insomnia or increased drowsiness), dizziness, headache.
On the part of the digestive system: dry mouth, nausea, heartburn.
Others: allergic reactions, general weakness, increased sweating.