Alpha Receptor Agonist
Hello dear students welcome back to my channel hylon pharmacology in today’s session let us learn about alpha receptor agonist so under alpha receptor agonist you need to remember the examples for alpha receptor agonist their mechanism of action and what are the important actions pharmacological actions their therapeutic indications adverse effects and finally
We’ll summarize the alpha receptor harmonized so coming to the examples for alpha receptor agonist we have phenylephrine xylometazolin propyl excidrin nephazoline and oxymetazoline please remember the phenylephrine is given through oral root whereas the xylometer zone propyl excidrin nephrozolin and oxymetazoline are given locally so all these drugs are
Sympatho in nature next moving on to the actions produced by this alpha receptor agonist so as you can see in the picture so it is a blood vessel on the blood vessel this alpha receptor agonist will going to cause vasoconstriction by acting on the alpha-1 receptor which are present in the blood vessels so by acting on the alpha-1 receptor it will going to cause
Vasoconstriction so there will be paso constriction of the blood vessels on the nasal mucosa again it causes vasoconstriction of the nasal mucosal blood vessels leading to vasoconstriction so it causes nasal decongestion whereas on the eye it acts on the alpha-1 receptor which is present on the radial muscle fibers of the iris by acting on the radial muscle muscle
Fibers of the high raise these alpha receptor organized will will cause dilatation of the pupil without any effect on accommodation so please remember on the blood vessel it causes vasoconstriction on the nasal mucosa it causes nasal decongestion in the eye it causes dilatation of the pupil without any effect on accommodation so coming to the mechanism of action
So once you have administered the alpha receptor bonus it will act on the sarcoplasmic reticulum so after acting on the sarcoplasmic reticulum it will going to cause a release of the calcium so subsequent release of the calcium will lead to increase in the calcium levels due to the subsequent stimulation of the sarcoplasmic reticulum so finally the increased
Calcium will going to activate the contractile tissue or it will going to activate the contractile mechanism in the respective vessels so coming to the pharmacokinetic property of this alpha receptor awareness these drugs are given intranasally or topically in the eye the plasma of life is around 3 hours whereas the plasma of life is longer in case of elders
Next moving on to the indication there is a therapeutic uses of alpha receptor agonist so therapeutically they are used as a nasal decongestant to relieve nasal congestion and also it can be used for ophthalmoscopy as it produces dilatation of the pupil so these are the two very important indications of alpha receptor agonist so moving on to the adverse effects
Profile of the alpha receptor agonist it causes hypertension as we have seen that on the blood vessel it causes vasoconstriction leading to increase in the blood pressure so in the patient who are having a risk for for hypertension or who are already having hypertension you need to avoid these drugs and also it can cause reflex bradycardia so please remember the
Adverse effects of alpha receptor are monister are it will cause hypertension and reflex buddy cardia so coming to the summarization of the alpha receptor awareness so you need to remember the examples so the examples are phenylephrine xylometazoline naphazoline oximeterzolin so the actions are it will going to cause vasoconstriction of the blood vessels then
It will cause nasal decongestion and the dilatation of the pupil without any effect on accommodation so the mechanism of action is on administration of alpha receptor agonist it acts on the sarcoplasmic reticulum leading to the release of the calcium from the sarcoplasmic reticulum so the subsequent activation of sarcoplasmic reticulum will lead to increased
Levels of the calcium which in turn activates the contractile mechanism in the respective muscle fibers so pharmacokinetic property it is given through intranasally or topically in the eye it has a plasma of life around three hours clinically it is used as a nasal decongestant to relieve nasal condition and also for ophthalmoscopy as it causes dilatation of
The pupil so coming to the adverse effects it will going to cause hypertension and reflex buddy cardia so this was all about the alpha receptor agonist so if you find this video useful please do subscribe to my channel i love pharmacology and do not forget to share and hit the like button for more updates on pharmacology thank you
Transcribed from video
Alpha RECEPTOR AGONIST | ANS PHARMACOLOGY – How To REMEMBER! By ilovepharmacology