Adding an IV steroid will augment the action of the bronchodilators by reducing inflammation surrounding the airways.
Terbutaline sulfate: is a beta-adrenergic receptor agonist which can be given as an alternative to Salbutamol to reverse bronchospasm.
Beclomethasone: A surface acting steroid dispensed in aerosolized form. It is used in the long-term treatment of chronic asthma to prevent recurrent attacks. It can not be used for acute attacks.
Prednisolone: In this scenario since the patient has history of recent vomiting, she will not be able to take oral prednisolone. A parentral hydrocortisone or intramuscular methylprednisolone are better alternatives.
Disodium cromoglycate: is a mast cell stabilizer used to decrease the occurrence and severity of asthma attacks. Once bronchospasm is established it has little use.