LAUSR

The review by Erumbala et al. [1] correctly proposing magnesium sulphate (MgSO4) as the first intravenous bronchodilator missed vital points of its pharmacological actions. The i.v. drug reduces or eliminates tachycardia and palpitation side-effects of β2-agonists [2–5]. As well as relaxing smooth muscle of the bronchi, vasculature, gut and uterus, MgSO4 slows cardiac atrial conduction [6, 7], and was used in the past to revert supraventricular tachycardia and fast atrial fibrillation [8, 9]. There is no evidence to be found for the 20–30 min infusion rate for i.v. MgSO4 of 40–75 mg.kg−1, and this infusion time will not create a sufficiently high serum level to relax bronchial smooth muscle. In acute-severe and life-threatening asthma i.v. MgSO4 followed by i.v. β2-agonist is safe [10]; an infusion time of 5 min for MgSO4 has evidence for the safety of this speed of injection in obstetric [11] and cardiac literature, albeit in adults. Intravenous magnesium sulphate allows safer intravenous β2-agonist delivery in acute-severe and life-threatening asthma attacks https://bit.ly/3veUpfC