Adrenergic agonist Non selective Alfa 1 and Alfa 2
oxymetazoline ( pharmacological action , uses , side effect , precaution//////
+////// selective Alfa 1 receptor agonist phenylephrine (pharmacological action
, uses , side effect ,) ////+///// selective Alfa 2 receptor agonist clonidine
Pharmacological action of oxymetazoline :
It selective on Alfa 1 receptor , which is present in blood
vessel of the nose and eyes , where it make contractions to relieve congestion
. eye redness causes by vasodilation
Uses of oxymetazoline :
- In cold cases to remove congestion .
- Eye redness related to chlorine during swimming pools or shampooing during a bath .
- This is only due to the effect on alpha 1 .
Side effect of oxymetazoline :
Frequent sneezing , burning sensation in the nose , dryness
of the throat and nose , so it is not used for more than five days , more
congestion and rebound of symptoms with greater intensity than before .
Selective Alfa 1 receptor Phenylephrine :
Pharmacological action of phenylephrine :
it dose not affect
the heart directly , but in the cases of systole and diastole in blood pressure
, especially since it is given by injection , but it dos not have any reflex
effect bradycardia
Uses of phenylephrine :
often like norepinephrine from given
in emergency and hospital , in addition to ophthalamic solution for contraction
eye .
Side effect of phenylephrine :
sleep problems , insomnia ,
irregular heart rate .
Precaution of phenylephrine :
- it can bother people who have asthma .
- it is prohibited for people who have problems with the heart and blood circulation
- rout of administration ( orally and topically ) .
selective Alfa 2 receptor clonidine :
pharmacological action of clonidine :
this drug acts on the
Alfa 2 receptor , and from it will reduce the release of norepinephrine and
other motor transmission of signals for sympathetic states .
used of clonidine :
- reduces symptoms in the event of a sudden withdrawal from certain countries
- , person who suddenly stops smooking
- In cases narcotic drugs that give a feeling of euphoria and happiness its used as antidote
- Choice of high blood pressure .
Side effect :
dry mouth , fatigue .
Precaution :
- caution should be taken against abrupt discontinuation of the drug
- Its considered safe for pregnant women n