Bronchodilators anaphylaxis

Epinephrine Nonselective and agonist Bronchodilation plus all other sympathomimetic effects on cardiovascular and other organ systems (see Chapter 9) Anaphylaxis, asthma, others (see Chapter 9) rarely used for asthma (B 2-selective agents preferred) Aerosol, nebulizer, or parenteral see Chapter 9... 

Chemical mediators include histamines (proteins that are potent vasodilators), cytokines (small proteins that mediate and regulate the immune system, inflammatory response and hematopoiesis [red cell production]), serotonin (CNS neurotransmitter), ECF-A (eosinophil chemotatic factor of anaphylaxis) and leukotrines. Histamine and ECF-A are strong bronchoconstrictors that stimulate the contraction of bronchial smooth muscles. Cyclic adenosine monophosphate (cyclic AMP or cAMP) maintains bronchodilation. Histamines, ECF-A, and... 

It was early demonstrated that although cromoglycate was effective as an asthma prophylactic in man it had no pharmacological action either as a bronchodilator or as a competitive antagonist to the mediators of anaphylaxis. The Fisons workers concluded that it acted at a third point, the mediator release step it did not prevent the combination of antigen with antibody but inhibited the release of the mediators which normally follows formation of the antigen-antibody complex. 

The discovery of Intal(l, disodium cromoglycate, DSCC) a decade ago provided a new therapeutic approach to the treatment of asthma (1,2). Pharmacologically, Intal differs from previously used drugs in that it is not a bronchodilator, antihistamine, or antiinflammatory agent. Intal acts by inhibiting the release of the mediators of anaphylaxis and thus offers an alternative to the conventional approach which seeks to alleviate the symptoms of an allergic attack with bronchodilators (2). 

This profile of pharmacological activity confirms that the pyrimido-[4,5-b]quinoline ester XXXV inhibits the release of the mediators of anaphylaxis, and is neither a bronchodilator nor an antihistamine. 

There are other compounds in the literature which seem to have a potentially useful blend of bronchodilator and antiallergy action. Compound IX, having a cromolyn-type structure, is effective in the passive cutaneous anaphylaxis test in rats as well as in the histamine aerosol test in guinea pigs (22). It has less cardiovascular effects than theophylline but causes some CNS stimulation. Compound X is a recent compound which in animals appears to be more potent than theophylline in its bronchodilator/antiallergic actions and also appears to have greater broncho-selectivity (23, 24). 

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. 

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