Sympatholytics in Control of Blood Pressure Flashcards
What are the two component of the Peripheral Nervous System?
Autonomic Nervous System [What your body does for you]
Somatic Nervous System [What your able to physically do]
What are the two components of the Autonomic Nervous System?
Sympathetic [Fight or Flight]
Parasympathetic [Rest and Digest]
What is the first line medication for HTN?
NOT sympatholytic drugs
-CCB, ACE-I, ARBs, and Diuretics are considered the first line
Should sympatholytics be used in pregnany?
NO, they are contraindicated in pregnancy; BUT you can use Methyldopa + Labetolol just fine?
What does the Baroreceptor do… again?
The stretch receptors within the aortic arch and the carotid sinus. When it stretches the a signal is sent to the medulla. Then a signal is sent from the medulla back to the target organs.
What will increase the baroreceptor response?
Drugs that reduce and increase the reflex tachycardia
What is the MOA of the Alpha-1 Antagonists?
Normally A1 receptors are going to release NE causing the Vasoconstriction.
-A1 Antagonists are going to block the release of NE, causing vasodilation which will decrease VR & CO = decrease in BP
-also helps relax the sphincter tone at the bladder, increasing urination during BPH
What are the Alpha-1 Antagonists?
The “-zosins”
-Prazosin, Terazosin, Doxazosin, Tamsulosin…
What are the side effects of The “-zosins”?
Orthostatic Hypertension [1st time], Tachycardia, Dizziness
What is Clonidines MOA?
Baroreceptor like: There is an increase of signal down the Vagus Nerve into the medulla, that signal will then travel back down the efferent nerve to the target organ, decreaseing VR, HR, CO = DECREASE in BP
What do the Alpha 2 Agonist do within the body?
With the agonism, there is a blockage of Nor-epi, causing inhibition of the Alpha and Beta receptors, causing a decrease in VR/CO = DECREASE in BP
What are the Alpha 2 Agonist?
Methyldopa, Clonidine
What is important about Methyldopa?
-One of a few medications that can be used during Pregnancy.
-Prodrug
What are the side effects of Clonidine?
Dry mouth, Sedation, Rebound Hypertension
What is a Non-selective Alpha Blocker?
An Alpha Blocker that has the ability to block both Alpha 1 and Alpha 2
How do the Non-selective Alpha Blockers work?
They are not as selective for Alpha 1; so they will have the ability to pass through the BBB binding to the Alpha 2 receptors there, causing the inhibition of the Negative Feedback Loop = INCREASE REFLEX TACHYCARDIA
What are the Non-selective Alpha Blockers?
Phentolamine, Phenoxybenzamine
What is important about Phentolamine?
-it is reversible
-has a very short duration
-binds to the ACTIVE site [directly inhibits Nor-epi & Epi]
What is important about Phenoxybenzamine?
-it is irreversible [receptor as nucleophile??]
-has a long duration
-binds to the ALLOSTERIC site [indirectly inhibits Nor-epi & Epi]
What do the First Generation Beta-Blockers do?
They are a Non-Selective Beta Blockers [B1 & B2]; blocking the effects of Epi = DECREASE in CO & VR causing a DECREASE in BP
The primary use of First Generation Beta-Blockers?
angina, cardiac arrhythmia, reduce tremors
What are the First Generation Beta-Blockers?
The “-olol” meds
-Propranolol, Pindolol, Acebutolol…
What is the importance of Propranolol?
-The 1st First Generation Beta-Blocker
-Unselective: Blocks both B1 & B2
-Will DECREASE BP by reducing Renin [B1]
What are the side effects of Propranolol?
Bronchospasm [B2], Bradycardia [B1], Rebound Tachycardia, Hypertension…
What is the importants of Pindolol & Acebutolol?
-Partial Agonists?
-used in Intrinsic Sympathomimetic Activity [?]
-Avoid in HF and IHD
What are some of the contraindications of the First Generation Beta-Blockers.
-Could increase the risk of diabetes: Masks diabetes by giving falsely lowered readings.
-Give false Blood Sugar readings [Tachycardia]
-CONTRAINDICATED: in those with COPD, asthma, CHF
What do the Second Generation Beta-Blockers do?
They are more B1 Selective [Cardiovascular]; will cause a DECREASE in HR + contraction = DECREASE in BP
-Have less bronchoconstriction [B1]
What are your Second Generation Beta-Blockers?
Metroprolol [Tartrate & Succunate], Atenolol
-Tartrate is a BID
What do the Third Generation Beta-Blockers do?
Will have the same effects as the B1 Antagonists [decrease HR = decrease BP; less Bronchoconstriction] + 2nd MOA
What are the Third Generation Beta Blockers?
Nebivolol, Betaxolol
What is the importance of Nebivolol?
It blocks B1 Receptors [Cardioselective] along with stimulating NO action = VASODILATION
What is the importance of Betaxolol?
Mostly used in managing and treating open-angle glaucoma along with essential hypertension [Blocking the receptors within the heart and smooth muscle = DECREASE BP]
What is the Non-selective Alpha-Beta Blockers?
A Non-Selective Alpha-Beta Blocker is going to block both Alpha 1 Receptors along with the Beta Receptors
-A1: Relax smooth muscle, decrease VR, decrease BP
-B1: Reduces the tachycardia
-B2: possible bronchospasms
What are the two Non-selective Alpha-Beta Blockers?
Carvedolol, Labetolol
What is the importance of Carvedolol?
Has both the A1 and B Blocking MOA
What is the importance of Labetolol?
Has both the A1 and B Blocking MOA
-Another drug that can be use in Pregnancy
