Adrenergic agonist , Non selective Alfa 1 and Alfa 2 receptor norepinephrine and oxymetazoline ( pharmacological action – on heart , blood vessel , lung and kidney ,- uses , side effect , contraindication . )
Ph. Action :
- The dose will controlled in selectivity on Alfa 1,2 and mostly given IV infusion because of the presence of norepinephrine in most synapse they have no benefits or any effect on lung or bronchial problems .
- Pharmacological action on heart : it dose not approach the heart directly , but rather work by construction the blood vessels leading to increase systolic and diastolic .
Through the receptor located on the aorta ,
it sends a signal to brain in the event of high blood pressure to give reaction
that work to expand and reduce the heartbeat . the amount of blood that goes to
the heart and there is a resistance to pumping .
- Pharmacological action on blood vessels : norepinephrine is better than epinephrine because it is more specialized on Alfa 1 , so it will cause construction of all blood vessels .
The blood vessels that rest supplying
skeletal muscle will have Beta 2 not Alfa so not causes vasoconstriction and it
will become vasodilation .
- Pharmacological action on kidney : the medicine will block the blood vessels that are going toward kidney . so the amount of blood will be small causing oliguria , enuresis it wont happen because basically I want to increase pumping .
- Pharmacological action of lung : it dose not work as basic option like epinephrine because ol selective weakness .
Uses :
It is
used only by shouk due accidents and so on . Of
course it is used little for reason vasoconstriction .
Side effect :
Mostly the same as drugs before , but less severely
because of the selectivity on Alfa receptor . such as : CNS side effect ,
arrhythmia , edema and the stronger is vasoconstriction
.
Contraindication :
- It is distinguished by its strong onset and the short duration of the actual effects drug in the body . gives IV infusion .
- If a leakage occurs when I inject it , all the cells surrounding vein will die necrosis .
- Knowing that it dose not inject in peripheral veins . the antidote for occur toxicity norepinephrine we should use phentolamine , work as antagonist Alfa receptor