Cardiovascular system Flashcards
list some alpha blockers? (3)
doxazosin
tamsulosin
alfuzosin
common indications for alpha blockers? (2)
- improve symptoms in benign prostatic enlargement
- add on therapy in resistant hypertension
MOA of alpha blockers?
most are highly selective for alpha 1 adreoreceptor found in smooth muscle i.e. blood vessels and urinary tract
stimulation causes constriction so therefore,
blockade with alpha1 blockers cause vasodilation and a fall in BP and reduced resistance to bladder outflow
adverse effects of alpha blockers?
postural hypotension
dizziness
syncope
alpha blockers should be avoided in what pt group?
those with existing postural hypotnesion
which of the alpha blockers doxazosin or tamsulosin are licensed for benign prostatic enlargement only?
tamsulosin
doxasozin is licensed for benign prostatic enlargement and hypertension
when in the day should doxasozin be taken?
at night time due to the BP lowering effect (at least initially)
how could you communicate the use of alpha blockers to the pt?
treatment for their urinary symptoms/ blood pressure
advise that it may cause dizziness when standing (particularly after first dose) so should take at night time
in hypertension doxasozin is typically reserved for pts who do not respond to other drug classes.
why in some men is it considered a lot earlier in treatment?
many men with hypertension also have benign prostatic enlargement
can treat both with a single drug
adenosine is the first line diagnostic and therapeutic agent in which heart condition?
supreventricular tachycardia (SVT)
MOA of adenosine?
agonist of adeonsine receptors
increases AV node refractoriness- this breaks re-entry circuit allowing normal depolarisations from SAN to resume normal HR (cardioversion)
when circuit does not involve AVN i.e. Atrial flutter adenosine will not induce cardioversion
adverse effects of adenosine?
bradycardia
asystole
(sinking feeling in chest, breathlessness and impending doom described by the patient however this feeling in only breif )
pts with which medical conditions cannot be given adenosine?
hypotension
coronary ischameia
decompensated HF
asthma/COPD
heart transplant
which antiplatelet agent can block the uptake of adenosine?
dipyramidole (dose of adeonsine must be halved)
how is adenosine prescribed?
IV followed by sodium chloride flush
only by expereinced doctors
Resus should be on stand by
how could you communicate adenosine use to the pt?
treatment to hopefully ‘reset’ their heart back to normal rythym
will feel horrible but will only last 30 seconds
continue to talk to pt during administration
following administratioin of adenosine how should the pt be monitored?
continous cardiac rythym strip
adrenaline is also known as?
epinephrine
common indications for adrenaline? (3)
- cardiac arrest
- anaphylaxis
- local vasoconstriction in tissues
MOA of adrenaline?
potent agonist of alpha 1, 2 and Beta 1, 2 adrenoreceptors
vasoconstriction of vessels supplying skin/mucosa (a1) whilst increasing HR and contraction force (B1). vasodilation of blood vessels supplying heart (B2) also bronchodilatioin
treatment with which drug can result in widespread vasoconstriction if given adrenaline?
B- blockers
(a1 vasoconstricting effect of adrenaline is not opposed by B2 medicated vasodilation)
adrenaline is given after the third shock in which cardiac arrest rhythms?
Ventricular fibrillation (VF) or pulseless Ventricular tachycardia (VT)
how should adrenaline be administered in 1) cardiac arrest and 2) anaphylaxis?
- pre-filled syringe IV followed by flush of sodium chloride
- IM injection into thigh halfway between hip and knee
name aldosterone antagonists?
spironolactone, eplerenone