Term
| can ear wax trigger the cough reflex? |
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Definition
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Term
| what are some common causes of a cough and their corresponding therapies? |
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Definition
| chronic bronchitis (avoid exposure to irritant chemicals, stop smoking), postnasal drip due to sinusitis (antibx, decongestants such as anticholinergics - seromucus glands of nose primarily cholinergic, and H1 blockers), postnasal drip due to allergy (avoid allergens, inhaled corticosteroids), GERD (elevate head of bed, high protein/low fat, no eating 2-3 hrs before bed, H2 blockers), CHF (digoxin, furosemide) |
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Term
| how should secondary coughing be approached? |
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Definition
| tx of the primary disorder |
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Term
| when are antitussives appropriate? |
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Definition
| when the cough is non-productive |
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Term
| how are the antitussives classified? what are the classifications? |
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Definition
| according to their M/A: alteration of mucociliary factors, decrease afferent input, supress cough center, decrease efferent limb, decrease respiratory muscles, and mucolytics |
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Term
| what are the two antitussive subcategories under the alteration of mucociliary factors heading? |
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Definition
| increase volume/decrease viscosity of mucus AND increased clearance of mucus |
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Term
| what antitussive drugs increase volume/decrease viscosity of mucus? what are the effects of their administration? |
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Definition
| guaifenesin, potassium iodide, iodinated glycerol, and terpin hydrate. the expectorant effect: reduction in adhesiveness/surface tension of mucus, and thinning of bronchial secretions -> leads to looser phlegm, enhanced removal of viscous mucus, and increased output of resp tract fluid (nonproductive coughs be come less frequent and more productive) |
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Term
| what is the most popular OTC antitussive compound that increases volume/decreases viscosity of mucus? what are the other options in this category? |
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Definition
| guaifenesin (robotussin) which makes mucus more liquid and thinner, "protussive", helps pts bring up what needs to be brought up. potassium iodide may be used, as well as iodinated glycerol and terpin hydrate |
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Term
| why can guaifenesin can also be considered "pro-tussive"? |
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Definition
| b/c it increases the volume and decreases the viscosity of the mucus - which helps the pt actually clear whatever needs to be coughed out |
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Term
| what are ADRs associated with guaifenesin? |
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Definition
| N/V, dizzines, headache, skin rash. if mixed in high levels with other CNS-depressing drugs such as antihistamines, lethal toxicity is possible |
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Term
| what characterizes potassium iodide in its use as an antitussive that increases volume/decreases viscosity of mucus? |
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Definition
| potassium iodide does make the mucus thinner (protussive), though it is not used as much. it is used *after sx to prevent atelectasis and in *CF. it accumulates in the thyroid gland, gastric juice and saliva and is renally eliminated. |
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Term
| what are ADRs/contraindications/drug interactions associated with potassium iodide? |
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Definition
| potassium iodide can cause skin rash, lesions of the small bowel (due to enteric coated K+ salts), hypothyroidism, iodine poisoning (iodism), and excretion in breast milk (skin rash & hypothyroidism in infant). contraindications include: impaired renal function, acute dehydration, hyperthyroidism, and living within 100 mi of a nuclear power plant (possible thyroid CA). potassium iodide may interact with lithium (potentiates hypothyroid effect) and potassium sparing diuretics (leads to hyperkalemia/cardiac arrhythmias) |
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Term
| how does iodinated glycerol compare to potassium iodide as an antitussive that increases volume/decreases viscosity of mucus? |
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Definition
| pretty much the same in terms of uses, ADRs, etc. it is additionally contraindicated in pregnant women, newborn infants and mothers who breast-feed. it contains 22% alcohol which is necessary to make the contents water soluble. |
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Term
| what characterizes terpin hydrate in its use as an antitussive that increases volume/decreases viscosity of mucus? |
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Definition
| terpin hydrate is generally not sufficent for expectorant effects in normal dosing, and is therefore used primarily as a vehicle for cough mixtures. it contains 42% alcohol, and is therefore contraindicated in pregnant women and those breast feeding - possibility of FAS (fetal alcohol syndrome) |
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Term
| what antitussive drugs increase the clearance of mucus? |
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Definition
| theophylline and beta-adrenergic agonists |
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Term
| how does theophylline increase the clearance of mucus? |
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Definition
| theophylline is a widely used bronchodilator related to caffeine (xanthine) w/some CNS stimulatory properties. it has an adrenergic effect of relaxing the bronchioles (specifically the smooth muscles of the bronchi/pulmonary blood vessels), allowing the mucus to be better cleared |
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Term
| how does beta adrenergic agonists increase the clearance of mucus? what are some of these drugs? |
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Definition
| the beta adrenergic agonists act as bronchodilators, allowing better clearance of mucus. these agents include albuterol, metaproterenol, and terbutaline |
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Term
| can drugs that decrease afferent input be used as antitussives? what drugs might be used for this? |
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Definition
| yes, these drugs target the sensory stimuli carried by the vagus to the medulla. lidocaine and benzonatate are both used for this effect. |
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Term
| what characterizes lidocaines use as a antitussive that decreases afferent input? |
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Definition
| lidocaine is used topically for short-acting cough suppression on pts during bronchoscopy or IV for pts w/persistent cough after general anesthesia and bronchoscopy. |
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Term
| what characterizes benzonatate use as a antitussive that decreases afferent input? what is a caveat for administration of this drug? |
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Definition
| benzonatate anesthetizes stretch receptors in the resp tract, and therapeutic doses do not depress the cough center. *pts need to swallow benzonatate whole b/c if they chew it, it will anesthetize the mouth (pt may accidentally bite their tongue) |
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Term
| what ADRs are asociated with benzonatate? |
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Definition
| chest numbness, pruritis, skin eruptions. OD: CNS stimulation (restlessness, tremors, convulsive seizures - cells that control motor activity may be suppressed), and cough/gag reflex can be diminished (pt may aspirate gastric contents) |
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Term
| what characterizes the use of NSAIDs as antitussives that decreases afferent input? which NSAIDs are used for this? |
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Definition
| indomethacin and sulindac reduce the production of prostaglandins which can reduced the cough developed by pts on ACE inhibitors (need to make sure the pt is not on anticoagulant therapy) |
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Term
| what antitussive drugs actually suppress the cough center of the brain? when should these drugs NOT be used? |
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Definition
| codeine (narcotic), caramiphen (non-narcotic anticholinergic), dextromethorphan (NMDA blocking agent), diphenhydramine (antihistamine w/significant sedative effects) |
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Term
| what characterizes codeine as an antitussive that depresses the cough center of the brain? |
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Definition
| codeine is a CNS depressant which will reduce respiratory function (however, a therapeutic dose should not produce a respiratory depression) after it undergoes biotransformation to morphine. codeine, as an opoid, will also dry out and thicken mucosal secretions (need to make sure this is not already a problem for the pt and that you are treating the correct cough etiology). pts will also need to be warned that this will show up on a drug screen. |
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Term
| pts with hx of what conditions may get respiratory depression with codeine adm? |
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Definition
| pts having an acute asthmatic attack, those with COPD, a severely reduced resp reserve, a pre-existing resp depression or those with hypoxia or hypercapnia |
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Term
| how might codeine adm affect pts w/asthma or pulmonary emphysema? |
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Definition
| codeine can produce respiratory insufficiency through suppression of the cough reflex and increased viscosity of the bronchial secretions (drying effect) |
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Term
| how might codeine adm affect pregnant women? |
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Definition
| codeine may prolong labor, it can cross the placental barrier, it may cause resp distress in newborns, and will appear in breast milk |
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Term
| how might codeine adm affect pediatric pts? |
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Definition
| DO NOT use any opioid in premature infants (immature BBB) and use w/extreme caution in older children |
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Term
| in what part of the pt population should codeine administration be done w/caution and reduced dosage? |
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Definition
| pts with acute abdominal conditions, convulsive disorders, significant hepatic/renal impairment and those on other CNS depressants |
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Term
| why is concurrent codeine and antihistamine administration potentially dangerous? |
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Definition
| some medications have both of these and drug addicts may easily OD on these b/c of the combined CNS depression effects |
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Term
| what are CNS ADRs associated with codeine? |
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Definition
| depression of respiration, sedation, impairment of driving skills (esp w/geriatrics), and disorientation |
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Term
| what are GI ADRs associated with codeine? |
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Definition
| xerostomia, nausea, vomiting, constipation, biliary tract spasm (increased pressure), and increased plasma amylase, lipase levels for 24 hrs |
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Term
| what are CV ADRs associated with codeine? |
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Definition
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Term
| what are GU ADRs associated with codeine? |
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Definition
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Term
| what are allergic ADRs associated with codeine? |
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Definition
| pruritis/laryngeal edema may occur following an IV dose |
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Term
| what is a weak anticholinergic that can be used as an antitussive that depresses the cough center? |
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Definition
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Term
| how is dextromethrophan used as an antitussive cough suppressing agent? |
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Definition
| dextromethorphan (d-isomer of codeine analog of levorphanol) is an NMDA blocking agent - which is its M/A. it is however, less potent than codeine. |
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Term
| what can happen if dextromethorphan is taken in the presence of MAO inhibitors (antidepressants)? |
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Definition
| the pt may undergo hyperpyrexia, myoclonic leg jerks, hypotension and coma |
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Term
| what is the effect of a dextromethorphan OD in children? adults? |
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Definition
| children: ataxia, resp depression, convulsions. adults: ataxia, slurred speech, dysphoria |
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Term
| can dextromethrophan be a drug of abuse? |
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Definition
| yes, and it will also trip preliminary drug screening tests for PCP |
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Term
| what characterizes diphenhydramine as an antitussive that depresses the cough center of the brain? |
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Definition
| diphenhydramine, an antihistamine has strong CNS sedative properties it also has significant anticholinergic (may dry out secretions - potentially worsen cough) and antiemetic effects. the newer antihistamines have less anticholineric activity, but are also less effective in terms of CNS depression. diphenhydramine also appears in breast milk and may cause paradoxical excitation in children |
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Term
| what characterizes ipratropium as an antitussive that suppresses the cough center? |
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Definition
| ipratropium is an anticholinergic (quaternary ammounium compound) that decreases efferent limb innervation (cough center to expiratory muscles/airway, receptors for which are in the head, neck and chest). it is administered via inhaler (minimal systemic absorption) and locally blocks M-sites, decreases ACh-induced cyclic GMP, which *results in bronchodilation (useful to treat coughs, and various types of asthma because it relaxes bronchiolar smooth muscle) |
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Term
| are there antitussives that can decrease respiratory muscles? |
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Definition
| yes pancuronium is a skeletal muscle blocking agent used to help with pts fighting their ventilators. vercuronium is another skeletal muscle relaxant that is similarly used. |
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Term
| what is the mucolytic antitussive? how does it work? |
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Definition
| acetylcysteine, which splits disulfide bonds and causes deopolymerization - which results in decreased viscosity of mucus. |
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Term
| what is the viscosity of pulmonary mucus secretion dependent upon? |
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Definition
| mucoprotein concentration and disulfide bonds between mucoproteins |
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Term
| when is acetylcysteine employed as a mucolytic antitussive? |
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Definition
| acetylcysteine is employed as a mucolytic antitussive in chronic bronchopulmonary disease such as emphysema and TB as well as acute bronchopulmonary disease (bronchitis, pneumonia), tracheostomy care, posttraumatic chest conditions, atelectasis due to mucus obstruction, diagnostic bronchial studies (bronchiograms), and tx of acetaminophen OD |
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Term
| how is acetylcysteine administered? what may be required additionally with its administration? |
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Definition
| nebulizer or direct instillation into tracheostomy - increased volume of liquefied bronchial secretions may require use of mechanical suction. |
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Term
| what are ADRS associated with acetylcysteine? |
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Definition
| N/V, bronchospasm, and drowsiness |
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Term
| what is the biotransformation of acetylcysteine? how does this help in its role as a reliever of acetaminophen OD? |
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Definition
| 4% of acetominophen is biotransformed into acetimidoquinone, a toxic metabolite - so in cases of its OD (>300 ug/mL @ 4 hrs post ingestion, signs include N/V, anorexia, diaphoresis, abdominal pain, and diarrhea), acetylcystine can be administered and it forms an alternate, non-hepatotoxic complex that will decrease plasma levels of acetimidoquinone. |
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