Drug Therapy for Cough and Nasal Congestion Relief Explained
School
Northwestern State University of Louisiana**We aren't endorsed by this school
Course
FA 1040
Subject
Biology
Date
Dec 12, 2024
Pages
5
Uploaded by CoachGrousePerson668
Chapter 31Drug Therapy for Nasal Congestion and CoughCommon coldSinusitisoNasal congestionoCoughProductive versus nonproductiveNasal decongestantsoPrototype: Pseudoephedrine (Sudafed); oPseudoephedrine has restricted use due to illicit manufacturing of amphetamineRelief of nasal obstruction and dischargeAdrenergic (sympathomimetic) drugsConstrict arterioles Reduce blood flow to nasal mucosaAdverse Effects – dysrhythmia, urinary retentionContraindications – hypertension, CADInteractions – caffeine, some herbsoOxymetazoline (Afrin) - TopicalMaximum 3 day use or patient can experience rebound congestionAntitussives - Suppress dry, hacking, nonproductive coughoPrototype: Dextromethorphan (nonnarcotic)Action – depressing cough receptor in the medulla or throatAdverse effects – nausea, drowsinessoBenzonatate (Tessalon Perles)oCodeine & hydrocodone (Narcotic)oTopical - Throat lozenges, cough dropsExpectorantsoPrototype: Guaifenesin (Mucinex)RESPIRATORY
Action – reduces the viscosity of secretionsMucolyticsoPrototype: Acetylcysteine - inhaledoAction - Liquefy mucus in respiratory tract; administered by inhalationEffective immediately after direct instillationoAdverse effect – airway inflammation and bronchospasmCold remedies (combination products) – education of package readingoMany contain antihistamine, nasal decongestant, and analgesicoSome contain antitussives, expectorants, etc.oMany are over-the-counter (OTC) medicationsDrug Therapy to Decrease Histamine Effects and Allergic ResponseHistamine is released in an immune or inflammatory response and binds to histamine receptor sites causing (H1 receptors)oContraction of smooth muscle in bronchi & bronchiolesoStimulation of nerve endings causing bronchoconstriction & coughoIncreased permeability of veins & capillaries allowing fluid to flow into subcutaneous tissuesoIncreased secretion of mucous glandsoStimulation of peripheral nerve ending causing pain and pruritisoDilation of capillaries causing flushingFirst-Generation H1Receptor Antagonists – oldest, inexpensive, widely availableoPrevent/reduce most physiologic effects that histamine produces at receptor sitesoInhibit smooth muscle constriction in blood vessels, respiratory, GI tractoDecrease capillary permeabilityoDecrease salivation and tear formationPrototype: diphenhydramineoAction – block histamine at H1 receptor sitesoAdverse Effects – CNS depressionOther Drugs in this class – Chlorpheniramine, hydroxyzine (Vistaril), promethazine (Phenergan)oBlack Box Warning for promethazine because of severe chemical irritation and tissue damage when administered intravenously.RESPIRATORY
Second-Generation H1Receptor Antagonists (gained specificity)oPrototype: cetirizine (Zyrtec)Action – Competes with histamine for receptor sitesAdverse Effects -Do not readily enter the brain from the blood, reducing CNS adverse effectsoOther drugs in this class – Loratadine (Claritin)Third-Generation H1Receptor Antagonists oPrototype: fexofenadine (Allegra)Action - Bind preferentially to peripheral rather than central H1receptors, Does not cross blood-brain barrier reducing occurrence of adverse drug reactions like drowsiness and sedation, provides effective relief of allergic conditionsDrug Therapy for Asthma, Airway Inflammation, and BronchoconstrictionAsthma – Airway inflammation, Bronchoconstriction, Airway hyperresponsiveness, Mucosal edema, Excessive mucous production.oBeta2-Adrenergics Albuterol (prototype), Levalbuterol(Xopenex), Salmeterol (Serevent)Action - stimulate beta2-adrenergic receptors in the smooth muscle of bronchi and bronchioles. The receptors, in turn, stimulate the enzyme adenyl cyclase to increase production of cyclic AMP, the increased cyclicAMP produces bronchodilation.Administration of albuterol by MDI is associated with fewer systemic effects than administration of higher dosages orally or by nebulizer.Adverse Effect - Muscle tremor is the most frequent, Major adverse effects are excessive cardiac and CNS stimulation. Symptoms of cardiac stimulation include angina, tachycardia, and palpitations. Symptoms of CNS stimulation consist of agitation, anxiety, insomnia, seizures, and tremors. Other reported effects may include serious dysrhythmias and cardiac arrest.oAnticholinergics Ipratropium (prototype)Action - Block the action of acetylcholine in bronchial smooth muscle, Reduces bronchoconstrictive substance releaseRESPIRATORY
Adverse effects - Cough, nervousness, nausea, GI upset, headache, dizzinessoMethylxanthinesTheophylline – prototype, other drugs – AminophyllineAction – Relaxes bronchial smooth muscle tissue, promotes bronchodilation, suppresses airway responsiveness to stimuli (that would trigger bronchospasm).Therapeutic range 5-15 mcg/ml, toxic at 20mcg/ml (anorexia, nausea, vomiting, agitation, nervousness, insomnia, tachycardia, dysrhythmias, tonic-clonic seizures)anorexia, nausea, vomiting, agitation, nervousness, insomnia, tachycardia, dysrhythmias, tonic-clonic seizuresAdverse effects - anorexia, nausea, vomiting, agitation, nervousness, insomnia, tachycardia, dysrhythmias, tonic-clonic seizuresoAnti-inflammatory Agents - CorticosteroidsBeclomethasone (prototype), other drugs budesonide (Pulmicort), fluticasone (Flonase), mometasone (Nasonex) – Topical. Prednisone & methylprednisolone (Solu-medrol) are systemic corticosteroidsAction - Treat acute and chronic asthma, other bronchoconstrictive disorders, resulting in Mucous secretion, Airway mucosa edemaAdverse Effects – headache, fungal infection, dry mouthoLeukotriene modifier drugsMontelukast (prototype, Singulair) - Long-term treatment of asthmaAction - Prevent acute asthma attacks induced by leukotriences, improves symptoms & PFT, decreases nighttime symptoms, not used forACUTE ATTACKAdverse Effects – mild – headache, nausea, psychomotor hyperactivityoImmunosuppressant monoclonal antibodiesOmalizumab (prototype, Xolair) – used to treat severe, persistent allergic asthmaAction – Inhibits IgE binding, limiting activation and release of mediatorsin allergic responseAdverse Effect – local reaction at injection site, headache, nausea, fatigueRESPIRATORY
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