Respiratory system drugs Flashcards
Antitussive drugs
-mostly opioids (or derivatives of) that directly suppress cough centre in the medulla oblongata
-anti tussive effect not related to normal opiate receptors (mu and kappa)
COUGH SUPPRESSANTS
Morphine
- antitussive drug
- effective antitussive at low doses
- not common for this tho due to SEs and abuse potential
Codeine (methylmorphine)
- antitussive drug
- equal antitussive effect as morphine but less analgesic (methylated morphine )
- used in SAs
Hydrocodone
- antitussive drug
- similar to codeine but more potent
- not for use with productive coughs and caution with cats
Hycodan
- antitussive
- hydrocodone combined with anticholingeric drug (homatropine) to prevent abuse
Dextromethorphan (DXM)
Robitussin
- antitussive drug
- opioid derivative but doesn’t act at normal opioid receptors and not analgesic or addictive
Butorphanol (Torbutrol, Torbugesic)
- analgesic and antitussive drug!
- more potent than morphine as analgesic and more potent than codeine/DXM as antitussive
- sedation
Beneficial effects of beta adrenergic receptor agonists in tx of airway diseases
- Bronchodilation
- Decreased release of mast cell inflammatory mediators
- Increased mucociliary clearance
Epinephrine (adrenaline)
- used in therapy of inflammatory airway diseases (IAD)
- stimulates alpha and beta receptors (alpha and beta adrengeric agonist)
- used only for emergency life threatening bronchoconstriction (anaphylaxis)
- short duration use only!
Isoproterenol (Isuprel)
- therapy of IAD
- potent beta receptor agonist–>bronchodilation
- emergency relief in horses
- inhalation/ injection
- short duration of action
- not long term suitable
Terbutaline (Brethine, Bricanyl)
- therapy of IAD
- potent beta 2 activity
- oral forms only in canada
- longer acting than isoproterenol
Salbutamol
- therapy of IAD
- potent beta 2 activity
- used systemically in dogs and horses
- metered dose inhaler most common administration form
Clenbuterol (ventipulmin)
- therapy of IAD
- commonly used for tx of recurrent airway obstruction (RAO) and heaves
- Beta 2 agonist
- injectable and oral form
- banned in food animals
Methylxanthines
-therapy of IAD
-includes theophylline, theobromine and caffeine.
-CNS stimulants
-resp effects: bronchodilation, decreased release of inflam mediators from mast cells, increase diaphragmatic contraction and increased mucociliary transport
(theophylline>caffeine>theobromine)
Anticholinergic drugs for therapy of IAD
- effective bronchodilators by inhibiting vagally mediated cholinergic sm. muscle tone in the resp tract (parasympatholytic)
- useful for asthma tx
Atropine
- anticholinergic drug for IAD therapy
- used for acute bronchodilation in horses,used to determine prognosis in RAO in horses
Glycopyrrolate
- anticholinergic drug for IAD therapy
- very potent, doesn’t cross BBB
Hyoscine Butylbromide
Buscopan
- anticholinergic drug for IAD therapy
- antispasmodic and anticholinergic that relaxes smooth muscle
- safer than atropine to determine prognosis of RAO in horses
- short term/emergency situations
Glucocorticoids for IAD therapy
- inhibit release of inflam mediators from macrophages and eosinophils (not mast cells)
- decrease synthesis of PGs, LKTs, and platelet activating factor
- enhance the action of beta 2 receptors in bronchial sm. muscle
- reduce severity of symptoms, improve peak expiratory flow, diminish airway hyper responsiveness, prevent exacerbations and prevent airway wall remodelling
Prednisolone/prednisone
-glucocorticoid for IAD therapy
Dexamethasone
- glucocorticoid for IAD therapy
- effective in RAO therapy in horses (fast)
Rapid acting and repositrol glucocorticoids
- IAD therapy
- used in emergency treatment of dyspneic cats (shock dose IV- pred or dex)
- long acting methylprednisolone acetate (depo-medrol) used for cats with bad owners
Cyproheptadine
- -IAD therapy
- serotonin antagonist (serotonin has role in allergen induced bronchoconstriction in cats)
- used as adjunct to glucocorticoids and bronchodilators to block bronchoconstriction in chronically asthmatic cats
Antimicrobial therapys for IAD therapy
-only necessary sometimes
in IAD therapy
-ex. cats where trachea-bronchial culture showed mycoplasma
-secondary bacterial infection from strep zooepidemicus can exacerbate IAD in horses (penicillin, ceftiofur, trimethoprim/sulfonamide)
Using inhalant therapy for IAD
- via metered dose inhalers (MDIs)
- high drug []s get directly delivered to the lungs and avoids systemic SEs
- shorter onset of action
- Nebulizers older and less efficacious that MDIs
Inhalational Salbutamol
-short acting beta 2 agonist for IAD therapy
-tx of choice for acute exacerbations of bronchoconstriction
-relaxes sm. m. and increases airflow in 5 min
-racemic mixture (R enant ->bronchodilation and anti inflam …S opposite!)
-
Inhalational Salmeterol (Serevent)
- long acting beta 2 agonist (IAD therapy)
- slow onset and long duration
- not recommend for acute bronchodilation but improves system control when used daily
Inhalational Glucocorticoids
- IAD therapy
- most potent inhaled anti inflam drugs available
- improves asthma control and normalizes lung function and prevent irreversible airway damage
Fluticasone(Flovent)
-inhaled corticosteroid for IAD therapy
Beclomethasone (Beclovent, Vanceril)
- inhaled corticosteroid for IAD therapy
Flunisolide (Aerobid)
- inhaled corticosteroid for IAD therapy
- severely affected cats must have this every day with prednisone
Triamcinolone (Azmacort)
-inhaled corticosteroid for IAD therapy
Ipratropium bromide (Atrovent)
- inhalant anticholingergic used for IAD therapy
- -derivative of atropine (less SEs)
- relieves bronchoconstriction and reduces mucous secretions
- efficacy with RAO in horses
Cromolyn sodium (Intal)
- inhalant mast cell stabilizers used in IAD therapy
- chloride channel blocker that modulates mast cell mediator release and eosinophil recruitment
- attenuation of viral induced airway inflam
Nedocromil sodium (Tilade)
- inhalant mast cell stabilizer used in IAD therapy
- chloride channel blocker that modules mast cell mediator release and eosinophil recruitment
- leads to attenuation of viral induced airway inflam
- broader spectrum of efficacy
Goals of expectorant and mucolytic drugs
- increase output of bronchial secretions
- enhance the clearance of bronchial exudate
- promote a productive cough
- drugs include: saline expectorants, direct stimulants, guaifenesin, acetylcystein and dembrexine
Saline expectorants
- stimulate bronchial mucous secretions via vagally-mediated reflex action on gastric mucosa.
- ex: ammonium chloride, ammonium carbonate, potassium iodide, calcium iodide and ethylenediamine dihydroiodide.
Volatile oils (eucalyptus/lemon oil)
- expectorant and mucolytic drugs
- DIRECTLY increase respiratory tract secretions
Guaifenesin (glyceryl guaiacolate)
- expectorant drug
- centrally acting muscle relaxant with expectorant effect (stimulate bronchial secretions via vagal paths)
- just changes particle clearance from the airways (speeds it up)
N-acetylcysteine (mucomyst)
- mucolytic drug
- mucolytic effect due t othe exposed sulfhydral group on cmpd, which interacts with the disulphide bonds on mucoprotein
- helps break down mucus and enhance clearance
- increase levels of glutathione also (scavenge free radicals)
- in aerosol form can cause bronchocontriction by reflex
Dembrexine (sputolysin)
- expectorant/mucolytic drug
- used for respiratory disease in horses
- alters constituents and viscosity of abnormal respiratory mucous and improves efficacy of resp clearance mechanisms
- also antitussive action and enhances [] of antibiotics in lung secretions
- powder form for feed
Alpha adrenergic agonists used as decongestants
- alpha adrenergic agonists cause local vasoconstriction of mm (decreasing swelling and edema)
- used topically as nasal decongestants for allergic and viral rhinitis (or systemically with antihistamines)
Doxapram
- stimulates medullary respiratory center and chemoreceptors of carotid artery and aorta to increase tidal volume.
- used in emergencies during anesthesia or to decrease the respiratory depressant effects of opiates and barbiturates.
- Used to stimulate respiration in newborns after difficult birth (under tongue)
