{"id":6589,"date":"2024-11-17T21:17:13","date_gmt":"2024-11-17T21:17:13","guid":{"rendered":"https:\/\/workhouse.sweetdishy.com\/?p=6589"},"modified":"2024-11-17T21:17:14","modified_gmt":"2024-11-17T21:17:14","slug":"pharmacotherapy-of-bronchial-asthma","status":"publish","type":"post","link":"https:\/\/workhouse.sweetdishy.com\/index.php\/2024\/11\/17\/pharmacotherapy-of-bronchial-asthma\/","title":{"rendered":"PHARMACOTHERAPY OF BRONCHIAL ASTHMA"},"content":{"rendered":"\n

Drug used in the treatment of bronchia asthma can be grouped into three main categories:<\/p>\n\n\n\n

    \n
  1. Bronchodilators
    a. \u03b2- Adrenergic agonists which include:
    \u0083 Non selective \u03b2-agonists e.g. adrenaline
    \u0083 Selective \u03b2-agonists e.g. salbutamol
    b. Methylxanthines; theophylline derivatives
    c. Muscranic receptor antagonists e.g. Ipratropium bromide<\/li>\n\n\n\n
  2. Mast cell stabilizers, e.g. cromolyn sodium, nedocromil, ketotifen<\/li>\n\n\n\n
  3. Antiinflammatory agents: corticosteroids<\/li>\n<\/ol>\n\n\n\n

    <\/p>\n\n\n\n

      \n
    1. \u03b2- ADRENERGIC AGONISTS (SYMPATHOMIMETIC AGENTS)<\/strong>
      a) Non- selective- \u03b2-agonists<\/li>\n<\/ol>\n\n\n\n
        \n
      • Epinephrine, ephedrine, isoprotenerol
        b). Selective \u03b2-agonists<\/li>\n\n\n\n
      • Salbutamol, terbutaline, metaproterenol, salmeterol, formaterol and etc

        Mechanism of Action<\/strong>
        \u03b2-Agonists stimulate adenyl cyclase and increase formation of cAMP in the airway tissues.
        They have got several pharmacological actions important in the treatment of asthma<\/li>\n\n\n\n
      • Relax smooth muscles<\/li>\n\n\n\n
      • Inhibit release of inflammatory mediator or broncho constricting substances from mast
        cells.<\/li>\n\n\n\n
      • Inhibit microvasculature leakage<\/li>\n\n\n\n
      • Increase mucociliary transport<\/li>\n\n\n\n

      • a. Non-selective \u03b2- agonists<\/strong><\/li>\n\n\n\n
      • <\/li>\n\n\n\n
      • Cause more cardiac stimulation (mediated by a \u03b21 receptor), they should be reserved for
        special situation.<\/li>\n\n\n\n
      • Epinephrine: very effective, rapidly acting bronchodilator especially preferable for the
        relief of acute attack of bronchial asthma.<\/li>\n\n\n\n
      • Administered by inhalation or subcutaneously.
        Side effects include arrhythmia and worsening of angina pectoris, increase blood pressure,
        tremors etc
        Contraindication:<\/strong> – hypertension, arrhythmia,
        Ephedrine:<\/strong> compared to epinephrine, it has longer duration of action but more pronounced
        central effect and lower potency. It can be given orally. The drug is currently infrequently used
        because of development of more efficacious and beta2-selective agents.
        b. Selective \u03b22- selective agonists<\/strong>
        Largely replaced non \u2013 selective \u03b22- agonists, are effective after inhaled or oral administration
        and have got longer duration of action. They are the most widely used sympathomimetics.
        Commonly used drugs both by oral and inhalation are Salbutamol, terbutaline, metaproterenol,
        pirbuterol and bitolterol.
        Salmeterol and formeterol are new generation, long acting \u03b22- selective agonists (with duration
        of action 12 hrs or more). These drugs appear to interact with inhaled corticosteroids to improve
        asthma control.
        Delivery of adrenoreceptor agonists through inhalation results in the greatest local effect on
        airway smooth muscle with least systemic toxicity.

        Side effects<\/strong>
        Tremors, anxiety, insomnia, tachycardia, headache, hypertension and etc.
        Contraindications:<\/strong> Sympathomimetics are contraindicated in patients with known
        hypersensitivity to the drugs
        Precautions: They should be used cautiously in patients with hypertension, cardiac dysfunction,
        hyperthyroidism, glaucoma, diabetes, pregnancy.<\/li>\n<\/ul>\n\n\n\n
          \n
        1. METHYLXANTHINES<\/strong><\/li>\n<\/ol>\n\n\n\n
            \n
          • The three important methylxanthines are theophylline, theobromine, and caffeine. The
            theophylline preparations most commonly used for therapeutic purposes is aminophylline
            (theophylline plus diethylamine).
            Mechanism of Action<\/strong>
            i. Competitively inhibit phosphodiesterase (PDE) enzyme leading to increased cAMP level.
            ii. They competitively inhibit the action of adenosine on adenosine (A1 and A2) receptors
            (adenosine has been shown to cause contraction of isolated airway smooth muscle and to
            provoke histamine release from airway mast cells.
            iii. Inhibit the release of histamines and leukotriens from the mast cells
            Of the three natural xanthines, agents theophylline is most selective in its smooth muscle
            effect, while caffeine has the most marked central effect.<\/li>\n\n\n\n

          • Pharmacokinetics<\/strong><\/li>\n\n\n\n

          • Only slightly soluble in water so has been administered as several salts containing varying
            amounts of theophylline base. Most preparations are well absorbed from gastro intestinal tract
            and metabolized by liver. Doses should be decreased in cases of liver disease and heart failure.<\/li>\n\n\n\n

          • Adverse Effects:<\/strong><\/li>\n\n\n\n

          • Anorexia, nausea vomiting, abdominal discomfort, headache, anxiety, insomnia, seizures,
            arrhythmias
            Theophylline is now largely reserved for patients in whom symptoms remain poorly controlled
            despite the combination of regular treatment with an inhaled anti- inflammatory agent and as
            needed use of a \u00df2 agonist.
            80<\/li>\n<\/ul>\n\n\n\n
              \n
            1. MUSCRANIC RECEPTOR ANTAGONISTS<\/strong>
              Mechanism of Action<\/strong>
              Muscarinic antagonist competitively inhibit effect of acetylcholine at muscarinic receptors \u2013
              hence block the contraction of air way smooth muscle and the increase in secretion of mucus
              that occurs in response to vagal activity e.g atropine sulfate
              Systemic adverse effects as a result of rapid absorption include urinary retention, tachycardia,
              loss of accommodation and agitation and local effects like excessive dryness of mouth limits the
              quantity of atropine used. Ipratropium bromide is poorly absorbed and does not readily enter the
              central nervous system thus permits the delivery of high doses to muscarinic receptor in the
              airways; hence, it can safely be used for bronchial asthma.
              Antimuscranic antagonist drugs appear to be slightly less effective than \u03b2- agonists agents in
              reversing asthmatic bronchospasm, The addition of ipratropium enhances the bronchodilation
              produced by nebulized albuterol in acute sever asthma. The antimuscarinic agents appear to
              be of significant value in chronic obstructive pulmonary diseases – perhaps more than asthma.
              They are useful as alternative therapies for patients intolerant of \u03b2 – agonists<\/li>\n\n\n\n
            2. ANTI-INFLAMMATORY AGENTS: CORTICOSTEROIDS<\/strong>
              Used both for treatment and prophylactic purposes
              Mechanism of action<\/strong>
              They are presumed to act by their broad anti inflammatory efficacy mediated in part by inhibition
              of production of inflammatory mediators. They also potentiate the effects of \u03b2- receptor agonists
              and inhibit the lymphocytic-eosinophilic airway mucosal inflammation
              Effects on airway<\/strong><\/li>\n<\/ol>\n\n\n\n
                \n
              • decreases bronchial reactivity<\/li>\n\n\n\n
              • increases airway caliber<\/li>\n\n\n\n
              • decreases frequency of asthma exacerbation and severity of symptoms
                The corticosteroids commonly used are hydrocortisone, predinisolone, beclomethasone,
                triamcinolone and etc.
                The drugs can be taken by inhalation as aerosol, oral, or an IV administration
                Because of severe adverse effects when given chronically, oral and parenteral corticosteroids
                are reserved for patient who need urgent treatment and those who have not improved with.
                bronchodilator. Aerosol treatment is the most effective way to decrease the systemic adverse
                effect of corticosteroid therapy. Abrupt discontinuation should be discouraged because of the
                fear of adrenal insufficiency. Doses should be decreased after improvement. Regular or
                controlled therapy is better maintained with aerosol corticosteroids.
                Clinical uses in bronchial asthma<\/strong><\/li>\n\n\n\n
              • Urgent treatment of severe asthma not improved with bronchodilator
                o IV, inhalation or oral.<\/li>\n\n\n\n
              • Nocturnal asthma prevention
                o oral or inhalation<\/li>\n\n\n\n
              • Chronic asthma
                o Regular aerosol corticosteroids
                Side effects:<\/li>\n\n\n\n
              • Suppression of the hypothalamic-pituitary-adrenal axis<\/li>\n\n\n\n
              • Osteoporosis<\/li>\n\n\n\n
              • Sodium retention and hypertension<\/li>\n\n\n\n
              • Cataract<\/li>\n\n\n\n
              • Impairment of growth in children<\/li>\n\n\n\n
              • Susceptibility to infection like oral candidiasis, tuberculosis<\/li>\n<\/ul>\n","protected":false},"excerpt":{"rendered":"

                Drug used in the treatment of bronchia asthma can be grouped into three main categories:<\/p>\n","protected":false},"author":1,"featured_media":6505,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[693],"tags":[],"class_list":["post-6589","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-drugs-action-on-the-respiratory-system"],"jetpack_featured_media_url":"https:\/\/workhouse.sweetdishy.com\/wp-content\/uploads\/2024\/11\/2779928.png","_links":{"self":[{"href":"https:\/\/workhouse.sweetdishy.com\/index.php\/wp-json\/wp\/v2\/posts\/6589","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/workhouse.sweetdishy.com\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/workhouse.sweetdishy.com\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/workhouse.sweetdishy.com\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/workhouse.sweetdishy.com\/index.php\/wp-json\/wp\/v2\/comments?post=6589"}],"version-history":[{"count":1,"href":"https:\/\/workhouse.sweetdishy.com\/index.php\/wp-json\/wp\/v2\/posts\/6589\/revisions"}],"predecessor-version":[{"id":6590,"href":"https:\/\/workhouse.sweetdishy.com\/index.php\/wp-json\/wp\/v2\/posts\/6589\/revisions\/6590"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/workhouse.sweetdishy.com\/index.php\/wp-json\/wp\/v2\/media\/6505"}],"wp:attachment":[{"href":"https:\/\/workhouse.sweetdishy.com\/index.php\/wp-json\/wp\/v2\/media?parent=6589"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/workhouse.sweetdishy.com\/index.php\/wp-json\/wp\/v2\/categories?post=6589"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/workhouse.sweetdishy.com\/index.php\/wp-json\/wp\/v2\/tags?post=6589"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}