LESSON 3: DRUGS ACTING ON THE RESPIRATORY Flashcards
Specifically refers to the complete failure of the tissues to get adequate supply of
oxygen
Anoxia
Refers to the reduce supply of oxygen, and is the more appropriate term for the usual
condition accompanying respiratory disorder.
Hypoxia
Refers to defective oxygenation of blood in the pulmonary circuit and is usually caused by a primary disease of the respiratory tract
Anoxic hypoxia
Due to deficiency of haemoglobin per unit volume of blood but the blood oxygen tension is normal
Anemic hypoxia
Caused by a reduction of the rate of blood flow to and from the capillaries
Stagnant hypoxia
Result from the failure of the tissue oxidation system in the presence of fully oxygenated blood.
Histotoxic hypoxia
retention of excessive carbon dioxide in the body, a condition term _______, failure to rid the
body of this excessive carbon dioxide leads respiratory acidosis.
hyper apnea
Initially the body tries to rid itself of excessive carbon dioxide by means of abnormally increasing the depth and in rate of respiration
hyperpnea
________ occurred when breathing becomes difficult and labored. Later, when the condition is not corrected, cyanosis & epistaxis sets in.
Dyspnea
is useful only in cases of anoxia and when the respiratory tract is not completely obstructed
Oxygen therapy
This may be instituted by intermittent – positive pressure ventilation (IPPV) during open – thoracic surgery or paralysis with a muscle relaxant drugs or poisons
Artificial respiration
are drugs that increase the volume and fluidity of secretions in the respiratory tract.
expectorants
Directly – acting expectorants
● Eucalyptus
● Pine oil
● Camphor
● Lemon oil
● Potassium iodide
Indirectly – acting expectorants
● Ammonium carbonate
● Ammonium chloride
● Potassium iodide
● Potassium citrate
● Guaifenesin
ɑ - Adrenergic stimulants drugs that inhibit respiratory secretion
● Phenylephrine
● Phenylpropanolamine
● Oxymethazoline
● Propylhexedrine
● Tuaminoheptane
blocks the effcts of histamine & provoked increase respiratory secretions. Not too effective in domestic animals
Antihistamine
used in preventing excessive resp. secretions due to cholinergic stimulation ex: during organophosphate poisoning,
Anticholinergic
example of drug in anticholinergic?
Atropine sulfate
this stimulant constrict blood vessels in mucus & upper resp. tract, therefore decreasing their leakniss (decongestant action), Orally or by Installation of external nares
a-Adrenergic stimulants
are almost always the best choice for inhibiting or reducing respiratory secretions:
a-Adrenergic stimulants
this are use to degrade & liquefy inflammation debris & liquefying inflammation debris,
Mucolytics & proteolytic enzymes
what are the 2 notable use of mucolytics ?
- acetylcysteine
- bromhexine
this breaks the disulfide bond result in liquefaction, it has an antidote of acetaminophen (paracetmol) poisoning, but it also has glutathione that neutralize reactive metabolities of paracetamol.
acetylcysteine
acetylcysteine is best administered in?
installation through resp. tract
this increase the volume & fluidity of resp. secretions, also increase concentration of immunoglobulin & of administration of oxytetracycline
Bromhexine
bromhexin is also use in the tx of _______ in conjunction w/ antibiotic theraphy
infectious tracheobronchitis
4 example of useful proteolytic enzyme?
- pancreatic dornase
- trypsin
- streptokinase
- streptodornase
are drugs used to suppress cough.
antitussives
a protective reflex initiated by the prescence of foreign materials in or by irritation of the resp. tract
cough
3 categories of antitussives;
- Narcotic antitussives
- Non-narcotic antitussives
- local acting antitussives
what are example of drugs in narcotic antitussives:
- codeine
- diheydrocodeine
- dihydrocodenone
- morphine
this 2 narcotic antitussive has high degree of selectivity for the cough center
Codeine & hydrocodeine
are highly efficacious for they are addicting & are subjected to dangerous drug control; toxic in cats
opiates
what are the drugs in non-narcotic antitussives:
- dextromethorphan
- Noscapine
- Butorphanol
- Phenothiazine tranquilizers
derivate of opiates but it’s not addicting, has little amount of analgesic activity & produces some degree of sedation
Dextromethorphan
potent as dextromethorphan
Noscapine
100x more potent than codeine & doesn’t have narcotic effect
butorphanol
what are the example of local acting antitussives:
- Menthol
- Tincture of benzoin
- Benzonatate
it act as directly on resp. mucous membranes to produce soothing or local anesthetic effect, administer orally or by inhilation
local acting antitussives
3 ways coughing can be surppress:
- by REDUCING viscosity in the airways w/ mucolytics
- by IRRITATED resp. mucous membrane w/ local antitussives
- by DEPRESSION of the cough center in the brain w/ central antitussives
causes relaxation of the bronchial smooth m. & increase the functional capacity of the respiratory tree. They also have dramatic ability to counter bronchoconstriction.
Bronchodilators
5 endogenous substances that mediate bronchoconstrictions:
- acetylcholine
- histamine
- serotonine
- bradykinin
- prostaglandin
are not tpo effective, it counteract bronchoconstriction caused by histamine released during allergic period, doesn’t have neutralizing effects
antihistamine
can counteract acetylcholine & induce bronchoconstriction.
Anticholinergic
by presenting the release of histamine from mast cells, it’e useful as a prophylactic agent to prevent attacks in chronic bronchoconstriction disorder; it’s not a bronchodilator
cromolyn sodium
_____ has dual action to cause bronchodilation & reduction of inflammation swelling of resp. tract; for acute attacks given IV, for chronic given ORALLY
corticosteroids
a potent bronchodilators, can be used as refractories (tolerance); it’s a drug of choice in case of bronchoconstrictions
methylxanthines
_____ is highly potent & efficacious drugs for the management of acute & chronic bronchoconstrictions
sympathomimetics
_____ is very potent, prompt but transient bronchodilator action, stimulate beta & alpha adrenergic receptor. Not ideal use for chronic because of fleeting effect.
Epinephrine
_____ is pure b2-adrenergic stimulator, comparable to epinephrine most effective if given orally.
Isoproterenol
_____ is slower onset but has prolonged effect of about 4-6 hours, better used for chronic, less potent but is effective when give orally
ephedrine
what are the selective bronchodilators:
- Albuterol
- Metaproterenol
- terbutaline
- clenbuterol
________ are sympathetic drugs but are specific b1 adrenergic stimulant without effecting b1 receptor in the heart
Selective bronchodilators
