Sympathetic Depressants Flashcards
Adrenergic blockers
Alpha adrenergic(block N.A but reverse Adr because N.A has weak beta)
Beta adrenergic
Both
Non selective alpha blockers (receptors on bv so VD)
Ergot alkaloids(no vaso dilation)- ergo tamine, toxine(partial agonist for alpha and serotonin), metrine
Imidazoline derivatives - tolazoline and phentolamine
Betahaloalkylamine - phenoxybenzamine and dibenamine
Selective alpha 1 blockers
Pra(first dose phenomenon - postural hypotension with the first dose) trima tera doxa zosin and indoramine
*trima and indoramine show no first dose
*tera, doxa and tamsulosin are long acting
Selective alpha 2 blockers
Yohimbine (research)3356
Prazosin works through posts synaptic alpha blocking as well as what for VD
Phosphodiesterase increasing CAMP decreasing Ca so VD
Is there accompanied reflex tachycardia in VD caused he prazosin
Noi
It’s selective for alpha 1
It increases both CGMP (drop HR) and CAMP (raise HR)
So no significant change in HR
Prazosin VDs both arteries and veins
So Decreases both preload and afterload
Suitable for heart failure
Also used in hypertension when taken orally
There’s postural hypotension with which drug
Prazosin
First dose phenomenon (trimazosin and indoramine don’t)
Tera , doxa and tamsulosin are long acting
Beta blockers (compete with isoprenaline and block beta effect on adrenaline)
Divided according to solubility and selectivity
Non selective
*Propranolol lipophilic - no intilrinsic sympathetic activity and 95%bound
*Nadolol hydrophilic
Oxprenolol
Pindolol
Sotalol - lipophilic
On the eye: Timolol - hydrophilic
Betaxolol
Levobunolol
Carteolol
Pindolol and oxprenolol have all the ISA
Selective beta 1 more than 2
Metoprolol lipophilic -HF
* Atenolol hydrophilic
Practolol
Acebutolol
* Bisoprolol hydrophilic - HF
* Nebivolol hydrophilic - HF
Esmolol lipophilic
Selective beta 2
Butoxamine
Blocks beta and alpha 1
Labetalol
* Carvedilol - HF
Medroxalol
Bucindolol
**prizidilol
Nadolol, atenolol, sotalol
Excreted unchanged in urine so contraindicated in renal disease
Augments hypertensive effect but blocks bronchodilator effect of adrenaline
Propanolol
Beta blockers with vaso D properties
Blockers with partial agonist activity - celiprolol, dilecalol and nebivAlol
Additional VD molecule - carvedilol, labetolol, medroxalol, bucindolol and prizidilol
Potent antihypertensive for peripheral vascular diseases and heart failure
Interfering with adrenergic release
Guanthedine
Interfering with adrenergic storage
Reserpine
Interfering with adrenergic synthesis
Alpha methyl dopa
Presynaptic alpha 2 stimulator(inhibitory)
Clonidine
Guanfacine and alpha methyl dopa
Imidazoline receptors agonists- rilmendine and moxonidine
According to solubility
Lipophilic pass bbb and have sedation side effects, depression and night mare plus hepatic first oass for 4 to 6hours
Hydrophilic doesn’t pass bbb and lasts 12 to 24 hours
Give sildenafil(viagra)
Orally on empty stomach 1hr before intercourse
Decrease in aqueous humour caused by
Beta blocker(propranolol)effect on the eye decreasing IOP
Class 2 antiarrhythmic action of beta blockers
Beta blockade
Sodium channel blocker
Quinidine like action
Local anaesthetic action
Inhibiting beta 1 in the kidney
Decreases renin decreasing BP
Hypoglycemia in beta blockers
Block beta 2 on liver
Atherosclerosis in beta blockade
B3 inhibition and decrease HDL
Propranolol on CVS
* give orally or slow IV
Angina prophylaxis
Acute MI - antiarrhythmic action plus blocks K uptake so reduces work and size of infarction
Arrhythmia after Sympathomimetics, thyrotoxicosis and digitalis
Hypertrophic Obstructive Cardiomyopathy
BV Aortic Aneurysm and varices in liver cirrhosis as it decreases COP and splanchnic circulation
BP hypertension
Pheochromocytoma
Tumor in adrenal gland
Treated by alpha and beta blockers
Loss of selectivity of beta blockers
In large doses
ISA Drugs under VD properties
Celiprolol
Dilevalol
Nebivalol
Therapeutic alpha uses
Hypertension with excess catechos
Primary Hypertension
PVD
Reverse VC by leakage of NA during infusion
Benign prostatic hyperplasia
Benign prostatic hyperplasia- no Contractions e.g prazosin and doxazosin
First pass in propranolol so
2/3 lost to liver (there’s glucoronic acid conjugation) and 1/3 in systematic circulation
-some are not bound and excreted unchanged in urine so renal disease contraindication
Propranolol Bbb so used as
Antiparkinsonian
Antianxiety
Plus prophylaxis in migraine
Most important effect of BB - CVS
Decreases chrono ino AV conduction cardiac work Oxygen
Effect of BB on BP
Presynaptic effect decreasing sympathetic and NA release
On heart
Kidney
Rest barorwceptir sensitivity
PG, VD BB, Decreased TPR - BV action
Blocks hypotensive Isoprenaline and Beta stinukant
Propranolol
Antagonizes bronchodilatkr Adr
May precipitate asthmatics
Beta blockers in angina
Decreases work of the heart plus BPplus anxiety so used in stable A but NOT in VARIANT as alpha is left unopposed so VC which may worsen the condition
Beta blockers in MI
Reduces the work of the heart plus size of infarct
Antiarrhythmic action
Hypokalemic action
With selective beta blocker, you’re less liable yo side effects
Less Reynaud’s phenomenon
Less Bronchospasm
Less Hypoglycemia
Less lipotropic changes
Less hypokalemia
Beta blockers in HF (moderate)
Prevent toxic catechos
Blocks RAS
Decreases incidenc of sudden death and increases survival in post infarction patients
-beta 1 more than 2 (affects heart more than bv)
Side Effects (SE)
In severe depression use hydrophilic BB
SE BB on heart
HB and HF
Not used with variant angina(worsens)
Not with verapamil abd diltiazem
SE BB on BV
Reynauds
Cold extremities
Numbness
- so not used in PVD plus reynauds
SE BB BP
Hypotension
SE BB respiration
Bronchial asthma
Sudden discontinuation of BB
Sympathetic overactivity
With angina and MI
Special drugs at the end
SDATE
Non selective mention sdate
PNST
Nadolol sdate
Angina
HT once a day
Sotalol sdate
Class 3 antiarrhythmic
Timolol sdate
In open angle glaucoma as eye drop
Avoided in heart block(it’s still a beta blocker)
Doesn’t affect size of pupil (does nothing for accommodation) as it decreases aqueous humor directly
Selective B mentioned at the end
MABEN
Nadolol
Atenolol
Metoprolol = Esmolol = Propranolol
Angina
Arrhythmia
Hypertension
Esmolol
Metabolised by blood esterase in liver
Ultra short half life - 10 minutes
In supraventricular arrhythmia and severe hypertension
Given IV
Nebivolol
Most B1 selective
N = NO for VD
May increase insulin sensitivity and doesn’t affect lipid profile
Beta and Alpha - Labetalol 3:1
No selective B so doesn’t affect CO and no ISA
Quick drop on BP because alpha and renin
No tachycardia
More labetalol - uses
Hypertension- IV in severe hypertension
Pheochromocytoma
* Carvedilol is also an antioxidant
Plus Medroxalol, and bucindolol exist
Antiadrenergic drugs
Adrenergic neuron blockers
Inhibit release
Guanthedine
Inhibit synthesis
Alpha methyl dopa
Reserperine
Inhibit storage plus mentioned under Tyramine
Alpha 2 agonists - centrally acting
Stimulates presynaptic alpha 2 in:
Brain stem - Decreased sympathetic flow
Kidney- Decreased renin
Nerve endings- Decreased NA
Plus decreased renal vascular resistance so hypertension with renal insufficiency
