OTC/Cough Pharm

Question 1

cough is produced in three consecutive processes - what are they

Answer 1

irritants stimulate receptors (throat, ears, esophagus, pleura, etc)

vagus sends afferent signals to medulla cough center

efferent signals go expiratory muscles (spinal motor), diaphragm (phrenic), and larynx (vagus)

Question 2

5 main categories in cough DDx

Answer 2

airway irritants, airways disease (asthma, bronchitis, etc), parenchymal disease, CHF, drugs (ACE inhibs)

Question 3

4 modes for further cough workup

Answer 3

imaging, PFTs, GI work up (rule out GERD), empiric tx (diagnostic tool)

Question 4

brand name and drug category of guaifenesin

Answer 4

mucinex- expectorant

Question 5

guaifenesin moa

Answer 5

reduces mucus viscosity (unknown for sure how)

no benefits in clinical data

Question 6

N-acetylcysteine moa, brand name, category

Answer 6

reduces disulfide bonds to degrade mucin proteins

mucomyst

mucolytic, given by inhalation

Question 7

benzonatate brand name, moa

Answer 7

tessalon, inhibits cough receptors in bronchioles to stop cough cascade before it begins

technically a local anesthetic, Na channel blocker

Question 8

benzonatate category

Answer 8

peripherally acting Na blocker

not OTC!

Question 9

what are the centrally acting antitussives?

Answer 9

dextromethorphan (robitussin) and codeine

Question 10

dextromethorphan moa

Answer 10

glutamate antagonist, inhibits glutamate signalling of efferent pathways to cough muscles

Question 11

dextromethorphan toxicities

Answer 11

dissociative disorders (amnesia, depersonalization, etc) along w/ potential for abuse

Question 12

codeine moa

Answer 12

opioid receptor agonist- binds to mu receptor on both pre and post synapse in CNS

pre: inhibition of Ca influx and thus neurotransmitter (glutamate) release
post: stimulation of K+ efflux, hyperpolarization

Question 13

a1 agonist decongestants

Answer 13

pseudoephedrine and phenylephrine (sudafed)

Question 14

sudafed/ sudafed PE moa

Answer 14

a1 agonists- induce vasoconstriction and reduce swelling in nasal mucous membranes

moa also works for hemorrhoids

Question 15

1st generation anti histamine decongestants

Answer 15

diphenhydramine (benadryl) and promethazine

Question 16

2nd generation anti histamines

Answer 16

loratadine (claritin), fexofenadine (allegra), ceterizine (zyrtec)

Question 17

histamine source and fn

Answer 17

released by mast cells during allergic response, triggered by IgE

receptors are found on many inflammatory cells

promote capillary permeability and vasodilation in the endothelium, inhibit sleep in the brain

Question 18

histamine role in pathology

Answer 18

excess vasodilation and cap permeability causes swollen nasal mucous membranes

Question 19

histamine role in the brain

Answer 19

inhibits sleep, promotes wakefulness

important neurotransmitter to H1, H2, H3 receptors

Question 20

main diff and similarity b/w 1st and 2nd gen anti histamines

Answer 20

1st gen cross blood brain barrier, inhibit histaminergic neurons and cause drowsiness

2nd gen dont cross BBB

both targeting H1 receptors

Question 21

3 other fns for promethazine

Answer 21

sedative- H1

anti emetic and anti psychotic - dopamine D2 receptor