Respiratory Drugs (NCM 106 Finals 2) PDF

DRUGS AFFECTING THE THE RESPIRATORY SYSTEM RESPIRATORY SYSTEM  The bronchial tubes are composed of three layers: Cartilage, muscle,...

DRUGS AFFECTING THE THE RESPIRATORY SYSTEM RESPIRATORY SYSTEM  The bronchial tubes are composed of three layers: Cartilage, muscle, and epithelial cells.  The respiratory system  The cartilage keeps the tube open,  Includes air passages, but it becomes progressively less pulmonary vessels, the lungs, abundant as the bronchi divide and and breathing muscles, aids get smaller. the body in the exchange of gases between the air and  The muscles keep the bronchi open; blood, and between the blood the muscles in the bronchi become and the body’s billions of cells smaller and less abundant, with only a few muscle fibers remaining in the terminal bronchi and alveoli.  Functions:  The epithelial cells are very similar in 1. Inhalation and Exhalation structure. 2. Exchange of gas between the lungs and the  The alveoli at the end of the bloodstream bronchioles form the respiratory 3. Exchange of gas between membrane. These structures are the bloodstream and body functional units of the lungs where tissues gas exchange occurs 4. Air vibration in the vocal cords creates sounds 5. Olfaction  The lungs are two spongy organs that fill the chest cavity, separated by the mediastinum, which contains the  The upper respiratory tract - The heart, esophagus, thymus gland, and upper portion is composed of the various blood vessels and nerves. nose, mouth, pharynx, larynx, and trachea.  The lungs are made up of the bronchial tree, the alveoli, the blood  The lower respiratory tract - The supply to the lungs, the blood lower portion is made up of the coming from the right ventricle to the bronchial tree, smallest bronchioles alveoli for gas exchange, and elastic and the alveoli. tissue.  a specific antigen (e.g. pollen,  The left lung - two lobes or sections. mold, dust) with a vigorous inflammatory response.  The right lung - three lobes.  nasal congestion, sneezing, stuffiness, and watery eyes UPPER RESPIRATORY TR ACT CONDITIONS  Sinusitis  The Common Cold  It occurs when the epithelial lining of the sinus cavities  Viruses cause the common becomes inflamed. cold. They invade the tissues of the upper respiratory tract,  The resultant swelling often initiating the release of causes severe pain due to histamine and prostaglandins pressure against the bone, and causing an inflammatory which cannot stretch, leading response. As a result, the to blockage of the sinus mucous membranes become passage. engorged with blood, the tissues swell, and the goblet  The danger of a sinus cells increase the production infection is that, if it is left of mucus. untreated, microorganisms can travel up the sinus  sinus pain, nasal congestion, passages and into brain runny nose, sneezing, watery tissue eyes, scratchy throat, and headache.  Pharyngitis and Laryngitis  Seasonal Rhinitis  Infections of the pharynx and larynx, respectively.  an inflammation of the nasal cavity, commonly called hay  Caused by common bacteria fever or allergic rhinitis or viruses.  This condition occurs when  Frequently seen with the upper airways respond to influenza, which is caused by a variety of different viruses  and produces uncomfortable substances into the lower respiratory symptoms or other respiratory tract inflammations along with fever, muscle aches and pains, and malaise  Bronchitis  Acute bronchitis occurs when LOWER RESPIRATORY TR ACT bacteria, viruses, or foreign CONDITIONS materials infect the inner layer of the bronchi.  Atelectasis  There is an inflammatory reaction at the site of the infection, resulting in swelling,  The collapse of alveoli, can occur increased blood flow in that as a result of outside pressure area, and changes in capillary against the alveoli—for example, permeability, leading to from a pulmonary tumor, a leakage of proteins into the pneumothorax or a pleural area effusion.  It occurs as a result of airway blockage, which prevents air from  Asthma entering the alveoli, keeping the lung expanded.  It is characterized by reversible bronchospasm,  This occurs when a mucous plug, inflammation, and hyperactive edema of the bronchioles, or a airways. collection of pus or secretions occludes the airway and prevents  The hyperactivity is triggered the movement of air. by allergens or nonallergic inhaled irritants or by factors such as exercise and  Pneumonia emotions.  The trigger causes an  Inflammation of the lungs immediate release of caused either by bacterial or histamine, which results in viral invasion of the tissue or bronchospasm in about 10 by aspiration of foreign minutes  Chronic Obstructive Pulmonary c) dextromethorphan hydrobromide Disease d) hydrocodone bitartrate  It is a permanent, chronic obstruction of airways, often  Pharmacokinetics: Antitussives are related to cigarette smoking. absorbed well in the GI tract, metabolized in the liver, and  It is caused by two related excreted in urine. disorders— emphysema and chronic bronchitis—both of which result in airflow  Pharmacodynamics: obstruction on expiration, as well as overinflation of the a. Benzonatate lungs and poor gas exchange  relieves cough caused by pneumonia, bronchitis, the common cold, and chronic pulmonary diseases such as DRUGS ACTING ON THE UPPER emphysema. RESPIRATORY TRACT  It can also be used during bronchial diagnostic tests such as bronchoscopy when patients  Antitussive must avoid coughing.  Decongestants  Antihistamine b. Dextromethorphan  Expectorants  the most widely used cough  Mucolytics suppressant ANTITUSSIVES  Contraindications:  patients who need to cough to  Antitussive drugs suppress or inhibit maintain the airways (e.g., coughing. postoperative patients and those  -used to treat dry nonproductive who have undergone abdominal cough. or thoracic surgery)  patients who are hypersensitive  The major antitussives include: to or have a history of addiction a) Benzonatate to narcotics (codeine, b) codeine hydrocodone). Codeine is a  narcotic and has addiction promoting drainage of secretions potential. and improved airflow.  Pregnancy and lactation  They are used to relieve the symptoms of swollen nasal  Adverse Reactions: Dizziness, membranes resulting from: Sedation, Headache, Nasal congestion, Burning in the eyes, GI a) allergic rhinitis upset or nausea, Constipation, Skin b) vasomotor rhinitis rash, itching, Chills, Chest numbness c) sinusitis e) common cold  Nursing Responsibilities May be classified as:  Report ineffectiveness of the a. Topical Nasal Decongestants drug to the prescriber  Encourage the patient to b. Oral Decongestants perform deep-breathing exercises c. Topical Steroid Nasal  Tell the patient taking an Decongestants opioid antitussive to avoid driving and drinking alcohol.  Decongestants are usually adrenergics or sympathomimetics DECONGESTANTS (imitate the effects of the sympathetic nervous system to cause vasoconstriction, leading  Decongestants decrease the to decreased edema and overproduction of secretions by inflammation of the nasal causing local vasoconstriction to membranes.) the upper respiratory tract.  This vasoconstriction leads to a shrinking of swollen mucous membranes and tends to open clogged nasal passages, providing relief from the discomfort of a blocked nose and  TOPICAL NASAL Rebound congestion occurs when the DECONGESTANTS nasal passages become congested as the drug effect wears off. As a result, patients tend to use more drug to  sympathomimetics decrease the congestion, thus initiating a vicious cycle of congestion–drug–  oxymetazoline (Afrin, and others), congestion, which leads to abuse of the phenylephrine (Coricidin, and decongestant.) many others), tetrahydrozoline (Tyzine), and xylometazoline (Otrivin).  Nursing Considerations  available as over-the-counter  Assess for any allergy. (OTC) preparations.  Monitor pulse, blood pressure, and cardiac auscultation to  available as nasal sprays that are assess CV and used to relieve the discomfort of sympathomimetic effects. nasal congestion  Perform bladder percussion to monitor for urinary retention  Pharmacokinetics: onset of related to sympathomimetic action is immediate, metabolized effects. in the liver and excreted in the  Evaluate nasal mucous urine. membrane to monitor for lesions that could lead to systemic absorption and to  Contraindications: lesion or evaluate decongestant effect. erosion in the mucous  Caution the patient not to use membranes that could lead to the drug for longer than 5 systemic absorption, glaucoma, days. hypertension, diabetes, thyroid disease, coronary disease, or prostate problems  Adverse Effects: local stinging and burning, increased pulse and blood pressure; urinary retention, use for longer than 3 to 5 days can lead to a rebound congestion.  ORAL DECONGESTANTS  Caution the patient not to use the drug for longer 1 week  pseudoephedrine (Triaminic Allergy Congestion, and many combination TOPICAL NASAL STEROID products) DECONGESTANTS  Taken orally to decrease nasal congestion related to the common  beclomethasone (Beconase, and cold, sinusitis, and allergic rhinitis. others), budesonide (Pulmicort Respules), flunisolide (generic),  Pharmacokinetics: Generally well fluticasone (generic), and absorbed and reaches peak levels triamcinolone (generic). quickly—in 20 to 45 minutes, widely distributed in the body, metabolized  treatment of allergic rhinitis and in the liver, and primarily excreted in to relieve inflammation after the the urine. removal of nasal polyps, effective in patients who are no longer getting a response with other  Contraindications: glaucoma, decongestants. hypertension, diabetes, thyroid disease, coronary disease, and  Pharmacokinetics: onset of prostate problems. action is not immediate, may actually require up to 1 week to  Adverse Effects: feelings of anxiety, cause any changes. If no effects restlessness, tremors, hypertension, are seen after 3 weeks the drug arrhythmias, sweating, and pallor, should be discontinued. rebound congestion  Contraindications: presence of  Nursing Considerations acute infections.  Assess for any allergy.  Cautions: avoid exposure to any  Monitor blood pressure, pulse, airborne infection, such as and auscultation to assess CV chickenpox or measles stimulations.  Evaluate respiration and adventitious sounds to  Adverse Effects: local burning, monitor drug effectiveness. irritation, dryness of the mucosa,  Monitor urinary output to and headache evaluate for urinary retention.  Nursing Considerations diphenhydramine (Benadryl, and others), hydroxyzine  Have the patient clear the (Vistaril, and others), meclizine nasal passages before (Antivert), promethazine using the drug to improve (Phenergan), and triprolidine its effectiveness. (generic).  Encourage the patient to continue using the drug regularly, even if results  Second-generation are not seen immediately, antihistamines include azelastine because benefits may take (Astelin), cetirizine (Zyrtec), 2 to 3 weeks to appear. desloratadine (Clarinex),  Monitor the patient for the fexofenadine (Allegra), development of acute levocetirizine (Xyzal), and infection that would require loratadine (Claritin) medical intervention  Therapeutic Actions and ANTIHISTAMINES Indications: block the effects of histamine at the histamine-1 receptor sites, decreasing the  Antihistamines block the release allergic response. They also have or action of histamine, a chemical anticholinergic (atropine-like) and released during inflammation that antipruritic effects, increases secretions and narrows airways. Antihistamines are found  Pharmacokinetics: well in multiple OTC preparations that absorbed orally, with an onset of are designed to relieve action ranging from 1 to 3 hours, respiratory symptoms and to treat metabolized in the liver, with allergies. excretion in the feces and urine.  First-generation antihistamines  Contraindications: Lactation include brompheniramine (J- and pregnancy, hepatic and renal Tan), carbinoxamine (Histex, impairment, arrhythmias. Palgic), chlorpheniramine (Aller- Chlor, and others), clemastine  Adverse Effects: drowsiness, (Tavist Allergy), cyproheptadine sedation, drying of the respiratory (generic), dexchlorpheniramine and GI mucous membranes, GI (generic), dimenhydrinate upset and nausea, (Dimentabs, and others),   Therapeutic Actions: Guaifenesin enhances the output  Nursing Considerations of respiratory tract fluids by reducing the adhesiveness and  Administer drug on an empty surface tension of these fluids, stomach, 1 hour before or 2 allowing easier movement of the hours after meals, to increase less viscous secretions. the absorption of the drug.  Suggest sugarless candies or  Pharmacokinetics: rapidly lozenges to relieve dry mouth. absorbed, with an onset of 30  Provide skin care as needed if minutes and a duration of 4 to 6 skin dryness and lesions hours. become a problem to prevent skin breakdown.  Contraindications: known  Avoid alcohol while taking allergy to the drug, pregnancy these drugs because serious and lactation and with persistent sedation can occur coughs which could be indicative of underlying medical problems. Adverse Effects: GI EXPECTORANTS symptoms (e.g., nausea, vomiting, anorexia), headache, dizziness  They increase productive cough to clear the airways  Nursing Considerations  They liquefy lower respiratory tract secretions, reducing the  Caution the patient not to viscosity of these secretions and use these drugs for longer making it easier for the patient to than 1 week and to seek cough them up. medical attention if the cough persists after that  Expectorants are available in time to evaluate for any many OTC preparations, making underlying medical them widely available to the condition. patient without advice from a  Advise the patient to take health care provider. small, frequent meals to alleviate some of the GI  Currently, the only available discomfort. expectorant is guaifenesin  Advise the patient to avoid (Mucinex, and others) driving or performing  dangerous tasks if endotracheal tube or dizziness and drowsiness tracheostomy. It is metabolized in occur to prevent patient the liver and excreted somewhat injury. in the urine.  Alert the patient that these drugs may be found in  Contraindications: Caution OTC preparations and that should be used in cases of acute care should be taken to bronchospasm, peptic ulcer, and avoid excessive doses esophageal varices because the increased secretions could aggravate the problem. M UCOLYT ICS  Adverse Effects: GI upset, stomatitis, bronchospasm, and occasionally a rash.  They increase or liquefy respiratory secretions to aid the clearing of the airways in high- risk respiratory patients who are  Nursing Considerations coughing up thick, tenacious secretions.  Avoid combining with other drugs in the nebulizer to  Mucolytics include acetylcysteine avoid the formation of (generic) and dornase alfa precipitates and potential (Pulmozyme). loss of effectiveness of either drug  Therapeutic Actions and  Dilute concentrate with Indications: Acetylcysteine sterile water if buildup affects the mucoproteins in the becomes a problem that respiratory secretions by splitting could impede drug apart disulfide bonds that are delivery. responsible for holding the mucus  Note that patients material together. The result is a receiving acetylcysteine by decrease in the tenacity and face mask should have the viscosity of the secretions residue wiped off the facemask and off their face with plain water to  Pharmacokinetics: The prevent skin breakdown medication may be administered by nebulization or by direct instillation into the trachea via an DRUGS ACTING ON THE LOWER RESPIRATORY SMOOTH MUSCLE RESPIRATORY TRACT  Oxygen is inhaled through the  Bronchodilators/Antiasthmatis mouth or nose  Xanthines  Travels down the bronchi and  Sympathomimetics bronchioles to be exchanged with  Anticholinergics CO2, which is a waste product in the body, exchanges CO2 for O2  Drugs Affecting Inflammation at the alveolar capillaries  Inhaled Steroids  Now those capillaries are pretty  Leukotriene Receptor fragile. When that exchange is Antagonists compromised, that's when we need the respiratory medications.  Smooth muscle is found in the walls of the bronchi and bronchioles  Bronchioles are smooth muscle tubes that impact flow of air through dilating or constricting  Bronchial spasms are when the smooth muscle just clamps down on those airways and the patients are unable to get a breath in.  ASTHMA PATIENTS HAVE 2 5. Airways are hyperreactive, AIRWAY PROBLEMS inflamed, and have excess mucus 1. Bronchoconstriction  Smooth muscle contraction CLINICAL SYMPTOMS OF ASTHMA 2. Inflammation  Immune response triggered by response to allergens  Exposure to triggers leads to  Airways become inflamed bronchospasm  Excess mucus  Narrowed airway  Airways are even more narrowed  Hard to catch your breath It is important to identify the patient’s  Breath sounds - wheezes, triggers! or a high-pitched whistling sound on inhaling  Cough  May feel dizzy or light- INFLAMMATION PROCESS headed 1. Patient is exposed to an allergen Recognize, be alert and watch for and it binds to IgE antibodies on signs and symptoms of a patient mast cells having an asthma attack! 2. Mast cells release their mediators (histamine, leukotrienes, BRONCHODILATORS prostaglandins). 3. Mast cell mediators cause  These are medications used to bronchoconstriction and the facilitate respiration by dilating inflammatory cells infiltration the airways. (eosinophils, leukocytes, macrophages)  They are helpful in symptomatic relief or prevention of bronchial 4. These inflammatory cells respond asthma and for bronchospasm (release their cytokines, associated with COPD. leukotrienes, interleukins)  Several of the bronchodilators mist for inhalation. If a patient is are administered orally and using a hand-held device or a absorbed systemically, giving mask, he or she should sit upright them the potential for many or in a semi-Fowler’s position and systemic adverse effects. place the correct amount of liquid (drug dose) in the nebulizer  Other medications are chamber, which is attached to a administered directly into the compressed gas system. The airways by nebulizers. These patient should breathe slowly and medications have the advantage deeply during the treatment. of fewer systemic adverse reactions.  Bronchodilators include xanthines, sympathomimetics, and anticholinergics. INHALERS  An inhaler is a device that allows a canister containing the drug to be inserted into a metered dose device that will deliver a specific amount of the drug when the patient compresses the canister. The inhaler has a mouthpiece and may also have a spacer, which is used to hold the dose of the drug while the patient inhales. This is advantageous if the patient has difficulty compressing the canister and inhaling at the same time or if inhaling is difficult.  A nebulizer uses compressed air to change a liquid drug into a fine BETA 2 ADRENERGIC AGONISTS  Long-acting agents  Used with anti-  Used for the treatment of inflammatory agents, symptoms associated with specifically inhaled asthma and chronic obstructive corticosteroids, to help pulmonary disease (COPD). control asthma a. Short-acting beta2-adrenergic agonists include:  PHARMACOKINETICS  albuterol (systemic, inhalation)  levalbuterol (inhalation)  Beta2 -adrenergic agonists  terbutaline (systemic) are minimally absorbed from the GI tract. b. Long-acting beta2-adrenergic agonists include:  After inhalation, beta2 - adrenergic agonists  albuterol (oral, systemic) appear to be absorbed  formoterol (inhalation) over several hours from  salmeterol (inhalation) the respiratory tract.  Arformoterol  Olodaterol  They’re extensively metabolized in the liver to inactive compounds.  Short-acting inhaled beta 2- adrenergic agonists  PHARMACODYNAMICS  The drugs of choice for  Beta2 -adrenergic agonists fast relief of symptoms in relax smooth muscle in the asthmatic patients airways and allow increased airflow to the lungs.  they are primarily used as a need basis or prn basis for asthma and COPD  XANTHINES effects within minutes, widely distributed and metabolized in the liver and excreted in the urine  Come from a variety of naturally occurring sources.  Contraindications and  These drugs were once the main Cautions: Pregnancy and treatment choices for asthma and lactation, patient with GI bronchospasm. However, problems, coronary disease, because they have a relatively respiratory dysfunction, renal or narrow margin of safety and hepatic disease, alcoholism, or interact with many other drugs, hyperthyroidism they are no longer considered the first-choice bronchodilators.  Xanthines are available for oral and parenteral use; the  aminophylline (generic), caffeine parenteral drug should be (Caffedrine, and others), switched to the oral form as soon dyphylline (generic), and as possible because the systemic theophylline (generic) effects of the oral form are less acute and more manageable.  Indications: have a direct effect  Adverse Effects: Therapeutic on the smooth muscles of the theophylline levels are from 10 to respiratory tract, both in the 20 mcg/mL. With increasing bronchi and in the blood vessels, levels, predictable adverse xanthines work by directly effects are seen, ranging from GI affecting the mobilization of upset, nausea, irritability, and calcium within the cell. They do tachycardia to seizures, brain this by stimulating two damage, and even death prostaglandins, resulting in smooth muscle relaxation, which increases the vital capacity that  Nursing Considerations has been impaired by bronchospasm or air trapping.  Administer oral drug with food or milk to relieve GI irritation if  Pharmacokinetics: rapidly GI upset is a problem. absorbed from the  Nicotine increases the gastrointestinal (GI) tract when metabolism of xanthines in given orally, reaching peak levels the liver; xanthine dose must within 2 hours. If given IV, peak be increased in patients who  continue to smoke while using bronchospasm, including that xanthines. caused by anaphylaxis; it is also  Provide periodic follow-up, available for inhalation. Because including blood tests, to epinephrine is associated with monitor serum theophylline systemic sympathomimetic levels. effects, it is not the drug of choice for patients with cardiac conditions. SYMPATHOMIMETICS  Pharmacokinetics: available only  Drugs that mimic the effects of as an inhalant include the sympathetic nervous system. arformoterol, formoterol, indacaterol and salmeterol.  One of the actions of the sympathetic nervous system is  Albuterol and dilation of the bronchi with metaproterenol - inhaled increased rate and depth of and oral forms. respiration.  Terbutaline – inhalant, oral and parenteral agent.  albuterol (Proventil HFA, and  Ephedrine - oral and others), ephedrine (generic), parenteral form (for IV, IM, epinephrine (EpiPen), formoterol and subcutaneous use). (Foradil), indacaterol (Arcapta),  These drugs are rapidly metaproterenol (generic), distributed after injection; salmeterol (Serevent), and they are transformed in the terbutaline (generic). liver to metabolites that are excreted in the urine. The inhaled drugs are  Therapeutic Actions and rapidly absorbed into the Indications: Most are beta2- lung tissue. selective adrenergic agonists.  Contraindications and That means that at therapeutic Cautions: cardiac disease, levels their actions are specific to the beta2- receptors found in the vascular disease, arrhythmias, bronchi diabetes, and hyperthyroidism, pregnancy and lactation  Epinephrine, the prototype drug,  Adverse Effects: CNS is the drug of choice in adults and stimulation, GI upset, cardiac children for the treatment of acute arrhythmias, hypertension,  bronchospasm, sweating, pallor,  Pharmacokinetics: These drugs and flushing are available for inhalation. Onset of action of 15 minutes when inhaled. Its peak effects occur in 1 to 2 hours, and duration of 3 to ANTICHOLINERGICS 4 hours.  Adverse Effects: dizziness,  Patients who cannot tolerate the headache, fatigue, nervousness, sympathetic effects of the dry mouth, sore throat, sympathomimetics might respond palpitations to the anticholinergic drugs ipratropium (Atrovent), tiotropium (Spiriva) Nursing Considerations  These drugs are not as effective  Provide small, frequent meals as the sympathomimetics but can and sugarless lozenges to relieve provide some relief to those dry mouth and GI upset. patients who cannot tolerate the  Advise the patient not to drive or other drugs. use hazardous machinery if nervousness, dizziness, and  Tiotropium was the first drug drowsiness occur with this drug approved for once-daily to prevent injury. maintenance treatment of,  Review the use of the inhalator bronchospasm associated with with the patient; caution the COPD patient not to exceed 12 inhalations in 24 hours to prevent serious adverse effects  Therapeutic Actions and Indications: Acts on the vagus nerve, which blocks or antagonizes the action of the neurotransmitter acetylcholine sites. Normally, vagal stimulation results on smooth muscle, causing contraction. By blocking the vagal effect, relaxation of smooth muscle in the bronchi occurs, leading to bronchodilation.  DRUGS AFFECTING little response to one agent INFLAMMATION and do very well on another.  It is usually useful to try  The second component of another preparation if one is treating obstructive pulmonary not effective within 2 to 3 disorders is to alter the weeks. inflammatory process that leads to swelling and further airway  Fixed combination drugs are narrowing. also available using some of these drugs  Effective treatment of asthma and COPD targets both components. FIXED COMBINATION  The drugs used to affect RESPIRATORY DRUGS inflammation are the inhaled steroids, the leukotriene receptors, and a mast cell  Advair Diskus and Advair HFA stabilizer (now only one OTC are combinations of fluticasone (a product is available), which can steroid) and salmeterol (a affect both bronchodilation and sympathetic agent). - asthma in inflammation patients 4 years of age and older.  Combivent is a combination of INHALED STEROIDS ipratropium (an anticholinergic agent) and albuterol (a sympathetic agent).  Found to be a very effective treatment for bronchospasm.  Symbicort is a combination of budesonide (a corticosteroid) and  Agents approved for this use formoterol (a sympathetic agent). include beclomethasone (Beconase AQ), budesonide  Anoro Ellipta combines (Pulmicort Respules, umeclidinium (an anticholinergic) Pulmicort Flexhaler), and vilanterol (a LABA). One fluticasone (FloventDiscus, inhalation a day for the Flovent HFA). maintenance treatment of COPD.  The drug of choice depends on the individual patient’s  Breo Ellipta combines fluticasone response; a patient may have (a corticosteroid) with the LABA  vilanterol. Once-daily inhalation  Nursing Considerations for the treatment of COPD and for the treatment of asthma  Have the patient use patients 18 years and older. decongestant drops before using the inhaled steroid to facilitate penetration of the  Therapeutic Actions and drug if nasal congestion is Indications: Inhaled steroids are a problem. used to decrease the inflammatory response in the  Have the patient rinse the airway. In an airway that is mouth after using the swollen and narrowed by inhaler because this will inflammation and swelling, this help to decrease systemic action will increase airflow and absorption and to help facilitate respiration. reduce the risk of oral thrush and decrease GI  Pharmacokinetics: rapidly upset and nausea absorbed from the respiratory tract, but they take from 2 to 3 weeks to reach effective levels, LEUKOTRIENE RECEPTOR and so patients must be ANTAGONISTS encouraged to take them to reach and then maintain the effective levels.  A newer class of drugs, this was developed to act more  Contraindications and specifically at the site of the Cautions: Inhaled steroids are problem associated with asthma. not for emergency use and not for use during an acute asthma  Zafirlukast (Accolate) was the attack or status asthmaticus. first drug of this class to be They should not be used during developed. pregnancy or lactation  Montelukast (Singulair) and  Adverse Effects: Sore throat, zileuton (Zyflo) are the other hoarseness, coughing, dry drugs currently available in this mouth, and pharyngeal and class laryngeal fungal infections are the most common  Therapeutic Actions and MAST CELL STABILIZER Indications: they selectively and competitively block (zafirlukast, montelukast) or antagonize  This prevents the release of (zileuton) receptors for the inflammatory and production of leukotrienes. bronchoconstricting substances when the mast cells are  Pharmacokinetics: These are stimulated to release these absorbed well in the GI tract, substances because of irritation metabolized in the liver, and or the presence of an antigen. excreted in urine.  Cromolyn (NasalCrom) is the  Contraindications: should be only drug still available in this used cautiously in patients with class, only available in an OTC hepatic or renal impairment form, and it is no longer because these conditions can considered part of the treatment affect the drug’s metabolism and standards because of the excretion; pregnancy and availability of more specific and lactation safer drugs  Adverse Effects: headache, dizziness, nausea, diarrhea, abdominal pain, elevated liver enzyme concentrations, vomiting.  Nursing Considerations  Evaluate liver and renal function tests to assess for impairments that could interfere with metabolism or excretion of the drugs.  Administer drug on an empty stomach, 1 hour before or 2 hours after meals;