Bronchodilators leukotriene antagonists

Antiasthmatics Bronchodilators Anti-inflammatories Leukotriene antagonists... 

Subgroups of Antiasthmatic Drugs Drugs useful in asthma include bronchodilators (smooth muscle relaxants) and anti-inflammatory drugs (Figure 20-2). Leukotriene antagonists may have both bronchodilator and anti-inflammatory properties. 

Figure 20-2. Subgroups of drugs discussed in this chapter. Leukotriene antagonists are shown as a separate category because it is not yet clear whether their benefits are primarily as bronchodilators or as antiinflammatory agents.

Zalirlukast, a cysteinyl leukotriene antagonist, has shown therapeutic efficacy in cough-variant asthma, even in patients unresponsive to inhaled bronchodilators and corticosteroids (Dicpinigaitis et al. 2002), whist a similar drug, montelukast has also... 

Leukotrienes are rapidly produced and released during a Type I reaction (Fig. 3). They are responsible for a massive bronchoconstriction in allergic bronchial asthma and attract leukocytes, thus being proinflamma-tory. Consequently, antagonists of the LTC recqDtor have been proven useful in the therapy of bronchial asthma, often in combination with bronchodilators (example montelukast). 

Leuko trienes are bronchoconstrictive substances released by the body during the inflammatory process. When leukotriene production is inhibited, bronchodilation is facilitated. Zileuton acts by decreasing tire formation of leukotrienes. Although the result is tire same, montelukast and zafirlukast work in a manner slightly differently from that of zileuton. Montelukast and zafirlukast are considered leukotriene receptor antagonists because they inhibit leukotriene receptor sites in the respiratory tract, preventing airway edema and facilitating bronchodilation. 

Acetazolamide is a carbonic anhydrase inhibitor that reduces aqueous humour production and is therefore indicated in glaucoma to reduce the intraocular pressure. Salbutamol is a selective, short-acting beta2-agonist used as a bronchodilator in asthma. Tolbutamide is a short-acting sulphonylurea used in type 2 (non-insulin dependent) diabetes mellitus. Chlorpromazine is an aliphatic neuroleptic antipsychotic drug used in schizophrenia. Zafirlukast is a leukotriene-receptor antagonist that is indicated in the prophylaxis of asthma but should not be used to relieve acute severe asthma. 

C.l. 52040) is a dye used as a diagnostic agent, toluidine blue O toluidine blue, tolycaine (ban. inn] is an amide series local anaesthetic which has been used mainly in dentistry, tomelukast [inn. usan] is a tetrazole derivative, a LEUKOTRIENE receptor ANTAGONIST with BRONCHODILATOR and ANTIASTHMATIC properties. 

Leukotriene receptor antagonists are a relatively new class of drugs that directly bind to leukotriene receptors in the lung preventing the inflammatory actions of leukotrienes particularly in the late phase of asthma. They are used in cases of asthma where there is a poor response to bronchodilators alone. 

PATIENTS TAKING LEUKOTRIEN E RECEPTOR ANTAGONISTS AN D LEUKOTRIEN E PORMATION IN H10ITORS. The nurse should never administer diese during an acute astiuna attack. These agents are used for die man ment of chronic asduna and are not bronchodilators. If used during an acute attack, diese dni may worsen die attack. 

Bronchodilators include sympathomimetics, especially selective agonists, muscarinic antagonists, methylxanthines, and leukotriene receptor blockers. 

Zafirlukast is an oral leukotriene receptor antagonist (LTRA) for the treatment of asthma, often used in conjunction with an inhaled steroid and/or long-acting bronchodilator. Zafirlukast blocks the action of the cysteinyl leukotrienes on the CysLTl receptors, thus reducing constriction of the airways, build-up of mucus in the lungs and inflammation of the breathing passages. 

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