Inhaled β2 agonist, such as albuterol, is the drug of choice for acute severe exacerbation of asthma. In cases of mild to moderate exacerbations, metered-dose inhalation (MDI) of a β2 agonist in conjunction with a spacer may be used. In more severe exacerbations, nebulized β2 agonist has been demonstrated to be most effective. In case of severe exacerbation with non- reponsiveness to β2 agonist inhalation/anticholinergic therapy, parenteral β2 agonist such as terbutaline may be administered. Ipratropium may also be utilized in cases of severe exacerbation.^[1] Steroid therapy remains the mainstay of therapy in the treatment of acute and sub-acute phases of exacerbation. Steroids speed in the resolution of airway obstruction and prevent a late-phase response; hence, shown to provide highly beneficial outcomes to patients with acute exacerbation presenting to the emergency department.^[2][3]

When an asthma attack is unresponsive to a patient’s usual medication, other treatments are available to the physician or hospital. These include:^[4]

• Oxygen to alleviate the hypoxia (but not the asthma per se) that results from extreme asthma attacks.
• Nebulized salbutamol or terbutaline (short-acting beta-2-agonists), often combined with ipratropium (an anticholinergic).
• Systemic steroids, oral or intravenous (prednisone, prednisolone, methylprednisolone, dexamethasone, or hydrocortisone). Some research has looked into an alternative inhaled route.^[5]
• Other bronchodilators that are occasionally effective in cases of non-responsiveness to initial drugs include:

• Intravenous salbutamol.
• Nonspecific beta- agonists, injected or inhaled (epinephrine, isoetharine, isoproterenol, metaproterenol).
• Anticholinergics, IV or nebulized, with systemic effects (glycopyrrolate, atropine, ipratropium).
• Methylxanthines (theophylline, aminophylline).
• Inhalation anesthetics that have a bronchodilatory effect (isoflurane, halothane, enflurane).
• The dissociative anesthetic ketamine, often used in endotracheal tube induction.
• Magnesium sulfate, intravenous.

• Intubation and mechanical ventilation, for patients in or approaching respiratory arrest.
• Heliox, a mixture of helium and oxygen, may be used in a hospital setting. It has a more laminar flow than ambient air and moves more easily through constricted airways.