Pharmacology bronchodilators

The desired outcome in the pharmacological treatment of asthma is to prevent or relieve the reversible airway obstruction and airway hyperresponsiveness caused by the inflammatory process. Therefore, categories of medications include bronchodilators and anti-inflammatory drugs. 

Early IPL studies focused mostly on the metabolism of the bronchodilators and corticosteroids or the pharmacological activity of bronchodilators on the ex vivo preparation. Recently, the absorptive transfer of beclomethasone dipro-prionate (BDP) has been measured following administration to the human lung reperfusion model by two different commercially available inhalers for which human pharmacokinetic data are available for comparison [43],... 

Pharmacology These agents are used to produce bronchodilation. They relieve reversible bronchospasm by relaxing the smooth muscles of the bronchioles in conditions associated with asthma, bronchitis, emphysema, or bronchiectasis. Bronchodilation may additionally facilitate expectoration. 

Pharmacology Ipratropium for oral inhalation is an anticholinergic (parasympatholytic) agent that appears to inhibit vagally mediated reflexes by antagonizing the action of acetylcholine. The bronchodilation following inhalation is primarily a local, site-specific effect, not a systemic one. 

Pharmacology Amphetamines are sympathomimetic amines with CNS stimulant activity. CNS effects are mediated by release of norepinephrine from central noradrenergic neurons. Peripheral activities include elevation of systolic and diastolic blood pressures and weak bronchodilator and respiratory stimulant action. Pharmacokinetics ... 

The most consistent pharmacological effect produced by marijuana is tachycardia, which is closely associated with the blood levels of A -THC. There is relatively little effect on blood pressure unless large quantities of marijuana are smoked, in which case there can be marked orthostatic hypotension. Cannabinoids are also vasodUatory, which results in the characteristic conjunctival reddening following marijuana smoking. They also reduce intraocular pressure and are capable of producing bronchodilation. 

The general pharmacological actions of adrenomimet-ics are described in detail in Chapter 10. The principal pharmacological effects that may be observed in humans treated for bronchospasm are bronchodilation, tachycardia, anxiety, and tremor. Stimulating Pz-adreno-ceptors produces all of these effects either directly or indirectly. 

The drugs most used for management of asthma are adrenoceptor agonists, or sympathomimetic agents (used as "relievers" or bronchodilators) and inhaled corticosteroids (used as "controllers" or anti-inflammatory agents). Their basic pharmacology is presented in detail elsewhere (see Chapters 9 and 39). In this chapter, we review their pharmacology relevant to asthma. 

Xanthine derivatives are a group of chemically similar compounds that exert a variety of pharmacologic effects. Common xanthine derivatives include theophylline, caffeine, and theobromine (Fig. 26-2) these compounds are frequently found in various foods and beverages (tea, coffee, soft drinks). Theophylline and several theophylline derivatives are also administered therapeutically to produce bronchodilation in asthma and other forms of reversible airway obstruction (bronchitis, emphysema).65,79 Theophylline and caffeine are also potent CNS stimulants, and some of the more common side effects of these drugs are related to this CNS excitation (see Adverse Side Effects, later in this chapter). 

Bronchial smooth muscle contains B2 receptors that cause relaxation. Activation of these receptors results in bronchodilation (see Chapter 20 Drugs Used in Asthma and Table 9-3). The blood vessels of the upper respiratory tract mucosa contain receptors the decongestant action of adrenoceptor stimulants is clinically useful (see Clinical Pharmacology). 

Dihydropyridines, are very attractive targets because of their wide range of pharmacological activities they have been reported for their vasodilating, antihypertensive, bronchodilating, anti-atherosclerotic, antioxidant, hepatoprotective,... 

This is most effectively achieved by physiological antagonism of bronchial muscle contraction, namely by stimulation of adrenergic bronchodilator mechanisms. Pharmacological antagonism of specific bronchoconstrictors is less effective either because individual mediators are not on their own responsible for a large part of the bronchoconstriction (acetylcholine, adenosine, leukotrienes) or because the mediator is not even secreted during asthma attacks (histamine). 

The basic pharmacological action of Ephedrine is that of a sympathomimetic. It does not contain a catechol moiety and is effective after oral administration. The drug stimulates heart rate and cardiac output and variably increases peripheral resistance as a result, ephedrine usually increases blood pressure. Stimulation of the a-adrenergic receptors of smooth muscle cells in the bladder base may increase resistance to the outflow of urine. Activation of S-adrenergic receptors in the lungs promotes bronchodilation. Ephedrine stimulates the cerebral cortex and subcortical centers to produce its effects in narcolepsy and depressive states. 

Various preparations of the plant Cannabis saliva have been used since ancient times for their behavioral and pharmacological properties. R. Mechoulam, The Pharmohistory of Cannabis Saliva, 1-19 (1986). More recently, it has been demonstrated that the active plant constituents, known as cannabinoids, produce a variety of effects including bronchodilation, increased heart rate, reduced intraocular pressure, analgesia, antiemesis, alteration in body temperature, as well as anticonvulsant and psychotropic activities. (W. L. Dewey, Cannabinoid Pharmacology, Pharmacol. Rev., 38 45 (1986)). 

Geumei A, Miller WF, Paez PN, Gast LR. Evaluation of a new oral beta2 adrenoceptor stimulant bronchodilator, terbutahne. Pharmacology 1975 13(3) 201—211. 

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