🩹 Dermatology Course:
Welcome back in this video we’ll talk about sympathomimetic medications these medications mimic the sympathetic activity as we know sympathetic system is activated in fight or flight mode so think of somebody who’s running and these medications will basically put the body in the same stress the sympathetics can be subdivided into direct mathematics and indirects
And mathematics the direct will act directly in the receptor and the indirect will work around the receptor but not directly on the receptor first in our list is dopamine and this works mainly on the beta1 receptor we know that the beta-1 receptor is mainly present in the heart and activation of this receptor ramps up the heart and increases its function so a
Patient taking dobutamine will have his or her heart rate increase as if they’re running so we mainly use dibetamine in cases of acute heart failure such as in cardiogenic shocks and sometimes to do the cardiac stress test to do the normal stress test the patient would have to run on a treadmill and we would attach a kg to the patient but if the patient cannot
Run for any reason such as new problems or obesity we can use the butamine to achieve the same heart rate next are these medications which mainly act in the beta 2 receptor beta2 is mainly present in the lungs so remember beta 1 acts on the heart because we have one heart beta 2 acts on the lungs because we have two lungs activation of this receptor by these
Medications causes the expansion of the bronchioles again think of somebody who’s running in the state of running the body would want more air to go into the lungs so normally the body would activate the beta2 receptor and the bronchioles will dilate easing the breath these medications basically achieve the same effect and we use them mainly in asthma and
Asthma attacks because the issue in asthma is constructive bronchioles next we have epinephrine and it activates both beta 1 and beta 2 in almost equal proportions so this increases the heart work and dilates the bronchioles because its effect is so wide we use it in anaphylactic patients or sometimes in shock syndromes because in these cases the body will be
Shutting down and epinephrine will ramp up the body next we have norepinephrine and this is basically a modified epinephrine which makes it act mainly on the alpha-1 receptors these are found in the vessels around the body activation of these receptors result in the construction of the vessels and increasing the blood pressure so we can use norepinephrine in
Hypotension and septic shock next we have phenolphthalein and this also acts on the alpha one receptor however the medication is mainly used as a topical drops so we use it mainly in ocular procedures again imagine somebody who is running when you’re running you want your eyes to dilate so you can see more broadly and more clearly this helps you to reach where
You’re going or run away from what’s chasing you and in ophthalmic procedures we want the same effect we want the eyes to dilate so we can work better and for that we use phenolphrine it is also the most commonly used decongestant along with atropine so these are the most important directs in bathymetrics and the first narrowest for the indirect is amphetamine
And this works by inhibiting the reuptake of epinephrines this is mainly used to treat narcolepsy and adhd next we have ephedrine and this causes the release of the stored catecholamines such as epinephrine it is a rarely used decongestant and it can be used to treat hypertension and finally we have cocaine and this is again a reuptake inhibitor and it causes
Basic constriction and it can be used as local anesthesia alright guys that’s all i have thank you so much for watching and hopefully this helps
Transcribed from video
Dobutamine, Albuterol, and Phenylephrine – Sympathomimetics By USMLE pass
