Autonomics Flashcards
Norepinephrine affects what receptors? What are adverse reactions due to this drug?
alpha and beta1 agonists Severe HTN due to stimulation of CV - but will reflexively cause bradycardia as the vagus nerve is trying to downregulate pressure - Can cause asthma and bronchospasm
Muscarinic antagonists such as atropine is used to treat what? What is its intended effect? What are common/adverse reactions?
to treat bradycardia especially vasovagal responses. - Increase HR Other M antagonists are used to treat asthma (antagonize M3 to relax bronchial smooth muscle) AE: Tachycardia with reflexive…. bradycardia -Constipation
Topical optical drugs acetylcholine chloride, carbachol, and pilocarpine cause what? What are they?
pupil constriction parasympathetic agonists
If giving a drug to help urinate more easily such as an alpha 1a inhibitor, what adverse effect will this have?
will affect ejaculation
When giving an alpha-antagonist drug, such as phentolamine or prazosin, what is the intended action? What are common reactions/adverse reactions?
To vasodilate peripheral blood vessels so as to treat dermal necrosis, HTN or Raynaud’s syndrome. Or, to treat BPH by antagonizing alpha1 (alpha1=sphincter contraction). AE: weakness, dizziness and orthostatic hotn due to vasodilation and decreased BP. - flushing due to vasodilation - nasal congestion - Reflex tachycardia (due to low BP)
What is the difference between norepinephrine and epinephrine?
Norepi is alpha & Beta 1 agonist Epi is alpha, beta 1 and beta 2 agonist Both will increase HR, contractility and consequently BP; & stimulate renin release But, epinephrine (beta 2) will also cause skeletal muscle vessel relaxation (to help provide more oxygen/blood flow to muscle), relax bronchiolar smooth muscle, relax bladder and stimulate glycogen breakdown and gluconeogenesis = increase in blood sugar
Topical optical drugs epinephrine and phenylephrine are what type of drugs? What effect will they cause?
sympathetic agonists pupil dilation
Beta 1 predominate where? Beta 2 predominate where?
Beta1 = heart Beta2 = lungs Yet, both are in each
When the ciliary muscle of the eye contracts, what happens? What receptor controls this? Is it sympathetic or parasympathetic?
Contracted ciliary muscle means relaxed suspensory ligaments which fattens lens to accommodate close vision. Controlled by M3 Parasympathetic
If I wanted to dilate your eyes, what 2 options do I have?
sympathetic agonists or parasympathetic antagonists
When giving an beta-antagonist drug, such as atenolol or propanolol, what is the intended action? What is the difference between the 2 drugs? What are common reactions/adverse reactions?
These are beta blockers. Beta blockers have subgroups. Propanolol blocks both beta 1 and 2. Atenolol blocks beta 1. Purpose is to lower blood pressure by decreasing heart rate. Also used to treat angina. AE: bradycardia and hence hotn and orthostatic hotn. - But, reflexive response leads to vasoconstriction leading to Raynaud’s and cold extremities - At high doses, can get dypsneic due to blocking beta 2 (especially with propanolol) *Do not administer/prescribe beta blockers to asthmatics to avoid this possible consequence.
Mydriasis is …
pupil dilation
When giving an alpha-agonist drug, such as phenylephrine, what is the intended action? What are common reactions/adverse reactions?
vasoconstrict peripheral blood vessels in order to increase blood pressure Other formulations and dosages are given only to vasoconstrict nasal vessels to treat nasal congestion. AE: Hypertension – That can cause a reflexive response of bradycardia - Can also cause urinary retention by stimulating alpha1 receptors in urinary sphincter
Miosis is …
pupil constriction
Topical optical drugs atropine and scopolamine are what type of drugs? What effect will they cause?
parasympathetic antagonists pupil dilation
Epinephrine affects what receptors? What are adverse reactions due to this drug?
Alpha, beta1 and beta 2 agonists. Adverse reactions: - severe htn - arrhythmia (pacemaker overload) - tissue necrosis if given subcutaneously by vasoconstricting -diaphoresis
Muscarinic agonists such as bethanechol is used to treat what and what is the intended effect? What are the common or adverse reactions?
Used to treat urinary retention and ileus. - contract bladder detrussor m and relax urinary sphincter - contract GI wall (peristalsis), relax GI sphincters and increase GI secretions = diarrhea AE: bronchospasm (M stimulation = contract bronch mm) - hotn (M decelerates SA node and contractility) - reflexive tachycardia
Describe the iris muscles.
Radial muscle - when contracted, dilates pupil (sympathetic - alpha 1) Circular muscle - when contracted, constricts pupil (parasympathetic - M3)
Patient enters ER for MI in severe pain. He is bradycardic. What are 2 types of drugs that you can give? Why?
1) beta agonist (sitmulate beta1 & 2 receptors to increase SA node, pacemaker=incr HR) or 2) M antagonist such as atropine (block parasym decelerating of HR in order to increase HR) - If responds to M antagonist, know that cause was vasovagal.
Glaucoma is…
reduced aqueous humor production
When giving an beta agonist drug, such as isoproterenol or dobutamine, what is the intended action? What are common reactions/adverse reactions?
Used to treat bradycardia or cardiac arrest – to increase heart rate and contractility AE: tachycardia and angina at higher doses - Dizziness and flushing due to excessive beta 2 skeletal muscle vessel dilation which can lead to orthostatic hotn. - nasal congestion due to vasodilation
Albuterol is an inhalant used to treat asthmatics. It is a beta agonist. Why does this work? What happens if the patient receives an hour long albuterol inhalation treatment due to an asthma attack?
Beta2 activation causes bronchial smooth muscle relaxation, decreasing the bronchospasm. tachycardia
What concerns should you have when treating with drugs that have an effect on the cardiovascular system?
Direct effect of drug and the indirect reflexive response of the result of the drugs.
