Salbutamol may cause fine tremor of skeletal muscles (particularly the hands), palpitations and muscle cramps. Tachycardia, tenseness, headaches and peripheral vasodilatation have been reported after large doses.
Salbutamol should be used with caution in patients with hyperthyroidism, cardiovascular disease, occlusive vascular disorders, hypertension and aneurysms. Hypokalaemia associated with high doses of Salbutamol may result in increased susceptibility to digitalis-induced cardiac arrhythmia. Tachyphylaxis with resistance may occur with prolonged use of high dosage. Care is necessary when treating patients with diabetes mellitus or closed angle glaucoma, and in those receiving antihypertensive therapy.
The symptoms with overdosage are angina, headache, nausea, vomiting, tremor etc. The preferred antidote for overdosage with Salbutamol is a cardio-selective beta-blocking agent but beta-blocking drugs should be used with caution in patients with a history of bronchospasm.