Pharm

Question 1

why is atropine not enough to counteract poisoning with a cholinesterase inhibitor (such as organophosphate)

Answer 1

atropine is an anticholinergic, so will counteract the effects of excess muscarininc stimulation

however pt would still be at risk of paralysis due to nicotininc overactivation (which needs pralidoxime, a cholinesterase reactivating agent)

Question 2

what is the diagnosis:

intracranial mass

• elongated cells with regular oval nuclei
• biphasic pattern of growth w/ areas of dense cellularity and less dense myxoid regions
• S-100 immunoreactivity

Answer 2

schwannoma

S100 positive b/c neural crest cell origin (as is melanoma)

Question 3

isoproterenol

• what does it bind to
• what effects

Answer 3

nonselective beta agonist

beta 1 effects:
-incr HR, cardiac contractility

beta 2 effects:

• vasodilation (decr bp)
• bronchodilation

Question 4

how do a1 agonists affect

• TPR
• heart

Answer 4

increases TPR

decrease HR (reflex)
decrease contractility (reflex)

Question 5

explain cause of rebound rhinorrhea (rhinitis medicamentosa)

Answer 5

topical alpha agonists used as decongestants, causes vasoconstriction of nasal mucosa vessels

overuse causes negative feedback, resulting in decreased endogenous NE syntheses and release due to negative feedback –> relative vasodilation and subsequent edema and congestion, exacerbating nasal convestion symptoms

this is called tachyphylaxis, occurs after a few days of use

Question 6

list 4 first gen antihistamines

list two second gen anihistamines

wha’s hte difference

Answer 6

1st gen-- are lipophilic and easily cross BBB causing signific sedation and cognitive dysfunction
hydroxyzine
promethazine
chlorpheniramine
diphenhydramine

2nd gen–less lipophilic
loratadine
cetirizine