Epinephrine should be administered as soon as the diagnosis is made. For this reason, intravenous epinephrine is given slowly in low doses. Continuous infusion may subsequently be needed to sustain the blood pressure. Useful in refractory anaphylaxis induced by beta-blocker therapy. Hypotension should be treated with intravenous fluids to expand the intravascular volume.
Antihistamines are useful as second-line therapy when a prolonged course is suspected.
Corticosteroids may not be helpful in immediate management of anaphylaxis but can be useful in treating prolonged urticaria or a late-phase response. Bronchospasm should be treated with inhaled beta2 agonists, with the option of using intravenous aminophylline in resistant cases. Some success has been achieved with glucagon, which may increase cardiac cyclic AMP, thereby enhancing cardiac output. Another option for refractory bronchospasm is 1 mg of atropine sulfate given by intravenous push. Beta blockers act as a competitive inhibitor of catecholamines, and beta2 agonists given in high doses may counteract this effect.