Pulmonary Pharmacology

Question 1

Are blood insoluble or blood soluble drugs more quickly distributed in tissues?

Answer 1

Blood insoluble drugs have a more rapid increase in partial pressure. Partially blood-soluble drugs have a slower increase in partial pressure.

Question 2

What is the affect of blood solubility on induction and recovery?

Answer 2

The more soluble the drug is in the blood, the longer induction/recovery will take

Question 3

Rate the following drugs in order of blood solubility and induction/recovery time: methoxyflurane, isoflurane, and nitrous oxide.

Answer 3

methoxyflurane (long recovery time, high solubility), isoflurane (medium recovery time, medium solubility), and nitrous oxide (short recovery time, low blood solubility)

Question 4

What is the fraction of delivered drug PP?

Answer 4

the alveolar concentration

Question 5

What is the role of lipid solubility in anesthetic pharmacologic potency?

Answer 5

Lipid solubility determines how well a drug can get across cell membranes, including the blood-brain barrier. The more lipid soluble, the more potent the anesthetic is.

Question 6

Rank the lipid solubility and MAC value (minimum alveolar concentration, pharmacologic potency) of the following drugs: methoxyflurane, isoflurane, and nitrous oxide.

Answer 6

Methoxyflurane (high lipid solubility, low MAC, more potent), isoflurane (medium lipid solubility, medium MAC, medium potency), nitrous oxide (low lipid solubility, high MAC, low potency)

Question 7

What is the Minimum Alveolar Concentration?

Answer 7

The anesthetic dose that produces anesthesia (immobility to a noxious stimulus) in 50% of a patient populations.

Question 8

What is the effect of acetylcholine on the bronchi?

Answer 8

Acetylcholine acts on the muscarinic acetylcholine receptors, increasing Ca++ concentrations, resulting in bronchoconstriction.

Question 9

What is the effect of norepinephrine on the bronchi?

Answer 9

Norepi acts on alpha adrenergic receptors to decrease cAMP resulting in bronchoconstriction

Question 10

What is the effect of epinephrine on the bronchi?

Answer 10

Epinephrine acts on beta2-AR to increase cAMP, resulting in bronchodilation

Question 11

What are the treatments for bronchoconstrictive airway disease?

Answer 11

Address causes (antibiotics), anti-inflammatory drug therapy, and symptomatic treatment (bronchodilators)

Question 12

What is the effect of acetylcholine on the mucus of the airway?

Answer 12

thick mucus

Question 13

What is the effect of epinephrine on the mucus of the airway?

Answer 13

Decreased mediators, watery mucus

Question 14

Albuterol

Answer 14

Beta2-AR agonist, increased cAMP which leads to bronchodilation, Aerosolized use in dogs and cats, most effective bronchodilator class, increase diameter of small/large airways, increase mucociliary clearance, decrease release of inflammatory mediators

Question 15

Clenbuterol

Answer 15

Beta2-AR agonist, which increases cAMP and leads to bronchodilation, use in horses in Canada and Europe, in small animal has low bioavailability in first-pass metabolism, side effects of cardiac arrythmias, mydriasis, excitement, etc.

Question 16

Theophylline

Answer 16

a type of methyxanthine (bronchodilator) that inhibits phosphodiesterase activity and decreases cAMP breakdown, also a competitive agonist at adenosine receptors (bronchoconstrictive effects). Results in dilation of large and small airways and mucociliary clearance and anti-inflammatory effects. Has high oral bioavailability, lots goes through hepatic phase 1 metabolism, low therapeutic index, serious side effects.

Question 17

What are examples of bronchodilators that target muscarinic receptors? (3)

Answer 17

Atropine, glycopyrrolate, ipratropium

Question 18

What can bronchodilators that target muscarinic receptors be used for?

Answer 18

severe asthmatic states unresponsive to other durgs, acute dyspnea, and bronchoconstriction produced by anti-choliesterase agents

Question 19

What are the differences between atropine and glycopyrrolate and ipatropium?

Answer 19

Glycopyrrolate and ipatrpium do not cross the BB barrier, ipatropium is more effective than atropine as a bronchodilator, glycopyrrolate has a longer duration of action than atropine but also slower onset

Question 20

What are the side effects of muscarinic receptor blockers?

Answer 20

tachycardia and decreased intestinal motility

Question 21

What are the goals of antitussive therapy?

Answer 21

Decrease the frequency and severity of coughing without compromising effective evacuation of bronchopulmonary secretions. Usually given for non-productive coughs

Question 22

What are the treatment strategies for cough in animals?

Answer 22

No treatment, remove causative stimulus, symptomatic treatment of non-productive cough

Question 23

What drugs can be given to the site of irritation (airways)?

Answer 23

Mucosal anesthetics, demulcents, mucokinetic agents, bronchodilators

Question 24

What drugs can be given to target the cough center (medulla)?

Answer 24

Opiates

Question 25

What are examples of opiate antitussive drugs?

Answer 25

Codine, butorphanol, dextromethorphan

Question 26

What is the mechanism of action of opiate antitussive drugs?

Answer 26

Decrease the sensitivity of the cough center to afferent stimuli, therefore decreasing the awareness of airway irritation

Question 27

What is the action of codine?

Answer 27

It depresses the respiration by blunting CO2 sensitivity of brain respiratory centers, has human abuse potential

Question 28

What types of drugs are butorphanol and dextromethorphan?

Answer 28

Opiate antitussive drugs

Question 29

Dextromethorphan

Answer 29

Isomer of a codine derivative, no action at opiod receptors, unsure of antitussive mechanism, effective if used in combination with a bronchodilator. No abuse potential

Question 30

Butorphanol

Answer 30

Agonist at opiod receptors (naloxone reverses), antitussive agent for use in non-productive coughs in dogs and horses. Some abuse liability