Beta-adrenergic agonists administration

Metaproterenol (Alupent, Metaprel) [Bronchodilator/ Beta-Adrenergic Agonist] Uses Asthma reversible bronchospasm Action Sympathomimetic bronchodilator Dose Adults. Neb 0.2-0.3 mL in 2.5-3.0 mL of NS Peds. Neb 0.1-0.2 mL/kg of a 5% soln in 2.5 mL NS Caution [C, /-] Contra Tach, other arrhythmias Disp Aerosol 0.65 mg/inhal soln for inhal 0.4, 0.6% tabs 10, 20 mg syrup 10 mg/5 mL SE Nervousness, tremors (common), tach, HTN Interactions T Effects W/ sympathomimetic drugs, xanthines T risk of arrhythmias W/ cardiac glycosides, halothane, levodopa, theophylline, thyroid hormones T HTN W/ MAOIs effects W/ BBs EMS Separate additional aerosol use by 5 min fewer 3i effects than isoproterenol longer-acting monitor lung sounds before/after administration... 

I. Pharmacology. Epinephrine is an endogenous catecholamine with alpha- and beta-adrenergic agonist properties, used primarily in emergency situations to treat anaphylaxis or cardiac arrest. Beneficial effects include inhibition of histamine release from mast cells and basophils, bronchodilation, positive inotropic effects, and peripheral vasoconstriction. Epinephrine is not active after oral administration. Subcutaneous injection produces effects within 5-10 minutes, with peak effects at 20 minutes. Intravenous or inhalational administration produces much more rapid onset. Epinephrine is rapidly inactivated in the body, with an elimination half-life of 2 minutes. 

Neve K A, Molinoff PB. Effects of chronic administration of agonists and antagonists on the density of beta-adrenergic receptors. Am J Cardiol 1986 57(12) 17F-22F. 

I. Pharmacology. Norepinephrine is an endogenous catecholamine that stimulates mainly alpha-adrenergic receptors. It is used primarily as a vasopressor to increase systemic vascular resistance and venous return to the heart. Norepinephrine is also a weak beta-1-adrenergic receptor agonist, and it may increase heart rate and cardiac contractility in patients with shock. Norepinephrine is not effective orally and is erratically absoihed after subcutaneous injection. After intravenous administration, the onset of action is nearly immediate, and the duration of effect is 1-2 minutes after the infusion is discontinued. 

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