[hope007]

Hey guys

1) What is the effect of nitrates on post MI mortality? Does it improve it?
If so, how?

2) Why is B-blockers contraindicated in vasospastic disorders (prinzmetal angina) ?

3) Why does digoxin toxicity increase when the patient is hypokalemic?
Although logically it should be the other way around!!

4) How does class I B anti arrythmics decrease Action Potential Duration?

Just trying to figure some sense behind facts
Appreciate your answers

 

[drahmednawaz]

1. Nitrates do have a mortality benefit. By decreasing infarct size.
2. B-bockers r contraindicated in every vasospastic disease; because they block beta receptors and leave alpha receptors unopposed. This would worsen vasospasm.
3. k and digox compete for the same binding site. with no k around, digox occupies more receptors. One step in management is to correct hypokalemia.
4. For this, u must watch Dr. Raymond' lecture in kap notes. He explains it very well.

If u want explanation for everything in pharma, watch Dr. Raymond. He has explanation for everything; won't disappoint u.

 

[hope007]

Dr. ahmed thank you very much for the elaborate answers and for taking the time to write them down

Best of luck

 

[im99]

Action of class 1b drugs is related to the concept of 'window current'.
(it's a current from phase 0 to phase 3 in the ventricular ms action potential.. during this current there is constant leakage of sodium into cell..and this maintains the APD) ; class 1b inhibit this window current and thus decrease the APD..