dariush
Forum Elite
Topics: 20
Posts: 356
|
4 subjects are involved in a study of the effect of autonomic drugs on blood pressure. each of the subjects has one pretreatment regimen as listed below:
1. Non
2. Atropin
3. Phentolamine
4. Propranolol
Following pretreatment, the same drug was given IV to each of the subjects. the result are summarized in the figure above. which of the following drugs was given to these subjects?
A. Ach (low dose)
B. Ach (high dose)
C. Epinephrine
D. Isoproterenol
E. Norepinephrine
F. Phenylephrine
please explain!
___________________
Allah (God) is watching over us...
|
| drk1980
Forum Guru
Topics: 147
Posts: 1,038
|
i can think only of isoproterenol that would reduce blood pressure under the given circumstances. im not confident though...
|
| msyamp
Forum Fanatic
Topics: 60
Posts: 1,462
|
i dint get your question. same drugs are given again? what is non in no 1? can you plesae post it again?
to match the above below and the diagram i go with phentolamine and phenylephrine
___________________
If you think you can You can! If you think you cant you are right again!!
|
| sturge_weber
Forum Guru
Topics: 77
Posts: 1,042
|
but why would phentolamine block isoproterenol
|
| msyamp
Forum Fanatic
Topics: 60
Posts: 1,462
|
no i said phentolamine vs phenylephrine
___________________
If you think you can You can! If you think you cant you are right again!!
|
| drk1980
Forum Guru
Topics: 147
Posts: 1,038
|
i think the Q is saying that 4 subjects are each given one of the drugs mentioned in the list, first being the control(none?).
after that they are all administered one drug from the answer key. and then the changes in BP are recorded as in the diagram. In all the subjects there is a % decrease in BP except in the one who had phenotolamine....thts the Q.
|
| sturge_weber
Forum Guru
Topics: 77
Posts: 1,042
|
o no msyamp, i was talking to drk
the thing that i inferred, is that the rug normally decreases the blood pressure, and it is blocked by phentolamine...because at 3 phentolamine blocks the action of the drug,
|
| msyamp
Forum Fanatic
Topics: 60
Posts: 1,462
|
hey drk. "then again the same drug is given" that means? ia m askingthis because i dont get the answer
___________________
If you think you can You can! If you think you cant you are right again!!
|
| drk1980
Forum Guru
Topics: 147
Posts: 1,038
|
"Following pretreatment, the same drug was given IV to each of the subjects."
First each of the assigned four different drugs are given to the four subjects. After that all the four subjects are given the same drug....that is One drug from the answer key.
its essential you understand the Q well, coz we are depending on you to give the answer 
|
| msyamp
Forum Fanatic
Topics: 60
Posts: 1,462
|
i cant go with acetyl choline because i causes dec bp in all including phentolamine.
i cant go with Epinephrine it doesnt cause fall in bp. in low dose also no change with propranolol
i cant go with
D. Isoproterenol .because it is b1 b2 agonist and shud not change bp with propranolol.
E. Norepinephrine can not decreasse heart rate
F. Phenylephrine is an alpha agonist so doesnot cause fall in bp. so the question is wrong
___________________
If you think you can You can! If you think you cant you are right again!!
|
| drk1980
Forum Guru
Topics: 147
Posts: 1,038
|
The drugs that can cause a fall in BP are Ach, epinephrine and isoproterenol right?
since BP falls even in the atropine subject i ruled out Ach.
since beta receptors are blocked int he propranolol subject epinephrine wud act only on alpha1 and cause a rise in BP, so i ruled that out
i ws left with isoproterenol. plz correct me..
|
| drk1980
Forum Guru
Topics: 147
Posts: 1,038
|
hmmm tht makes sense...the Q cud be wrong!
|
| sturge_weber
Forum Guru
Topics: 77
Posts: 1,042
|
but the q here is why would phentolamine block the action of isoproterenol
|
| sturge_weber
Forum Guru
Topics: 77
Posts: 1,042
|
ya the q seems wrong to me too
|
| msyamp
Forum Fanatic
Topics: 60
Posts: 1,462
|
i think the question is you give above drugs first and then give one of the below drugs and then above drugs again for the respective individuals. let us try that
___________________
If you think you can You can! If you think you cant you are right again!!
|
| msyamp
Forum Fanatic
Topics: 60
Posts: 1,462
|
than anser is phenyl ephrine
___________________
If you think you can You can! If you think you cant you are right again!!
|
| skyhigh
Forum Guru
Topics: 105
Posts: 561
|
ISn't the question asking which one of the drugs in the answer choices is given, following pretreatment with the above 4 drugs?
then, I would say that it is acetylcholine, because ach does not have any effect on alpha receptors, which phentolamine blocks, there is no effect on the subject treated wiht phentolamine. Also isn't phentolamine an irreversible alpha blocker.
and the BP remains decreased in the other subjects.
I don't think it is epinephrine, NE, phenylephrine, b/c these would increse BP in the first patient.
I don't think it is isoproterenol because it acts on beta one receptors, which can increase heart rete and beta two receptors which do bronchodilation.
Plz do correct me.
|
| drk1980
Forum Guru
Topics: 147
Posts: 1,038
|
iam confused! i actually dont see any of the drugs causing that reaction.
Dariush, maybe u shd provide the answer and we will work our way backwards!
|
| drk1980
Forum Guru
Topics: 147
Posts: 1,038
|
skyhigh, phentolamine is reversible. its phenoxybenzamine that is irreversible.
|
| sturge_weber
Forum Guru
Topics: 77
Posts: 1,042
|
where has the diagram gone
|
|
| |
| | | | | | | | | | | | | | | | | | | | |
