The most common side effect of Salbutamol Syrup 2 mg/5 mL is fine tremor of the hands, which may interfere with precise manual work. Tension, restlessness and a rapid heart-beat may also occur. There have been very rare reports of muscle cramps. Hypersensitivity reactions such as angioedema, urticaria, bronchospasm, hypotension and collapse have rarely been reported. Potentially serious hypokalemia may result from β2-agonist therapy. Occasional headaches have also been reported. As with other drugs in this class, rare reports of hyperactivity in children have been reported.