Beta2-adrenergic agonists

The mode of action of theophylline is different from that of Beta2-adrenergic agonists and anticholinergic agents, so it is still used in the treatment of selected patients with asthma or chronic obstructive pulmonary disease. 

Rennard SI, Anderson W, ZuWallack R, Broughton J, Bailey W, Friedman M, Wisniewski M, Rickard K. Use of a long-acting inhaled beta2-adrenergic agonist, salmeterol xinafoate, in patients with chronic obstructive pulmonary disease. Am J Respir Crit Care Med 2001 163(5) 1087-92. 

Selective beta2-adrenergic agonists have fewer side effects then epinephrine and are given by aerosol or as a tablet. These include albuterol (Proventil, Ventolin), isoetharine HCl (Bronkosol), metaproterenol sulfate (Alupent), sandeterol (Serevent), and Terbulahne SO4 (Brethine). 

Kobilka, B. K. (2002). Agonist-induced conformational changes in the beta2 adrenergic receptor. / Pept. Res. 60, 317-321. 

Krumins, A. M., and Barber, R. (1997). The stability of the agonist beta2-adrenergic receptor-Gs complex Evidence for agonist-specific states. Mol. Pharmacol. 52, 144-154. 

Synonym Formoterol fumarate Trade name Oxeze Indications Asthma, bronchospasm Category Adrenergic beta2-receptor agonist Half-life 10-14 hours... 

Category Adrenergic beta2-receptor agonist Half-life 3-4 hours... 

Inhalational selective beta2-adrenergic receptor agonists (albuterol, terbutaline, fenoterol, and bitolterol) have a rapid onset of action and are effective for 3 to 6 hours. Formoterol and salmeterol are longer-acting agents (12 hours) and may prove useful in treating nocturnal symptoms. 

Fenoterol (200 to 400 meg by inhalation), a beta2-adrenergic receptor agonist, is being used in patients with moderate to severe asthma, with chronic obstructive pulmonary disease, in protection against exercise-induced asthma, and for acute treatment of asthma attack. However, no apparent advantage of fenoterol over equipotent doses of albuterol or terbutaline has been demonstrated in clinical trials (see also Figure 94). 

The uterus contains both alpha- and beta2-adrenergic-receptor sites. Stimulation of the alpha-receptor site causes contraction stimulation of the beta2-receptor site causes relaxation. Therefore, beta2-receptor agonists such as rito-drine hydrochloride (Yutopar) and terbutaline sulfate (Brethine) are used to suppress premature labor. 

Dobutamine is a betaj, beta2 and alphaj adrenergic agonist and carvedilol is a non-selective beta blocker, but at low doses it is primarily a selective betaj adrenergic antagonist and it is also an alphaj antagonist. It was proposed that the drop in blood pressure was caused by vasodilation due to vascular beta2 receptor activation, which was not blocked by low doses of carvedilol. ... 

Fig. 6. In vitro P2AR expression. Relative expression of on P2AR in transgenic cells after exposure to p-agonist varies according to genotype at positions 16 and 27. Expression is relative to untreated cells of the same genotype. (Data from McGraw DW, Forbes SL, Kramer LA, et al. Polymorphisms of the 5 leader cistron of the human beta2-beta(2)-adrenergic receptor regulate receptor expression. J Clin Invest 1998 102 1927-32.)...

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