Week 1 Cardiac Pharmacology 4 of 4 Flashcards
slide 49-64
the 2008 poise study - name the positive indication and negative indication that the study concluded
beta blockade offered cardiac protection in coronary heart disease
showed a significant increase all cause mortality (particularly in patients who became septic or hypotensive)
name the classification of labetalol
non selective beta blocker alpha blocker
labetalol beta to alpha blockade
7:1
unlike standard beta blockers, what does labetalol produce due to its alpha blocking properties
vasodilation
IV dose labetalol (weight base) IV dose (non weight based)
weight base 0.25mg/kg PRN
non weight based 5-10mg PRN
labetaolol IV infusions dose
2mg/min
labetalol duration of action
2-6hrs (depending on the dose)
what must be adequate in order to give labetalol
I feel like this goes without saying, but its in the power point
because of beta and alpha blockade- adequate HR must be present
what are the concerns with anemia and periop beta blockers
anemia may further limit 02 delivery
beta blockers are associated with worse outcomes when Hgb levels are decreased by
> 35%
should beta blocker therapy be started on day of surgery
NO
in patients in whom beta blocker therapy is initiated, when should therapy be initiated
begin perioperative beta blocker therapy far enough in advance to assess safety and tolerability preferably more than one day before surgery
should beta blockers be continued in patients undergoing surgery who have been on beta blockers chronically
YES
how is beta blocker management after surgery guided?
Do we administer it no matter what after surgery?
it should be guided by clinical circumstance independent of when patient was started on medication
in patients with intermediate or high risk Myocardial ischemia noted in preoperative risk stratification test when it is reasonable to begin perioperative beta blockers
it may be reasonable to begin perioperative beta blocker given the circumstance
in patients with three or more revised cardiac risk index (RCRI) risk factors eg. diabetes mellitus, heart failure coronary artery disease, renal insufficiency or cerebrovascular accident. when is it reasonable to begin beta blockers
before surgery.
in patients with a compelling long term indication for beta blocker therapy but no other RCRI risk factors. initiating beta blockers in the perioperative setting as an approach to reduce perioperative risk - will this benefit the patient
uncertain of benefit
beta blockers may benefit vascular surgery patients at high risk for ___ but not for stroke
MI
metoprolol may not be the best choice of beta blocker in the periop period - what is the reason for this?
pharmacogenetics variation in metabolism
what gender benefits from beta blockers with reduced MI
Men
what gender suffered from clinically significant increases in CHF with betal blocker use
women
what situations where beta blockers are contraindicated?
asthma
Brady arrhythmias, acute heart failure advanced heart block, an adrenergic agonist such as clonidine may have some benefit
should we start beta blockers immediately before surgery, emergency surgery or in patient with prior cerebrovascular disease or sepsis
NO
HR should be titrated to what prior to surgery
55-70
name the three main anticholinergics
atropine glycopyrrolate scopolamine
what is the anticholinergics drug classification
competitive antagonist of acetylcholine at muscarinic receptors.
Sedation
atropine
scopolamine
glycopyrrolate
scopolamine +++
atropine +
glycopyrolate
antisialagogue
compare anticholinergic
Scopolamine +++
glycopyrrolate ++
atropine +
increase Heart rate
compare anticholinergic
atropine +++
glycopyrrolate ++
Scopolamine +
relax smooth muscle
compare anticholinergic
atropine ++
glycopyrrolate ++
scopolamine +
mydriasis, cycloplegia
compare anticholinergic
scopolamine +++
atropine +
glycopyollate 0
prevent motion induced nausea
scopolamine +++
atropine +
glycopyrrolate 0
decrease gastric hydrogen ion secretion
atropine +
scopolamine +
glycopyrrolate +
atropine IV dose
0.4-0.6mg
onset of atropine
1-2 min
name the prototype anticholinergic
atropine
belladonna alkaloid are what two medications
atropine & scopolamine
atropine can be used concurrently with anti cholinesterase for what purpose
reversal of muscle relaxants
atropine is a tertiary amine what does this allow atropine to do
cross the BBB
at clinical doses of atropine do you see cns effects
no its rare
at low doses of atropine what may result
transient bradycardia
what is the elimination half time of atropine
4hrs
what medication do we avoid in patients with narrow-angle glaucoma because it increases intraocular pressure
atropine
atropine overdose or belladonna alkaloid toxicity manifest as
extreme antimuscarinic effects with potential progression to CNS depression and coma
metabolism of atropine
1/2 liver with remainder unchanged in the urine
anticholinergic overdose mneumonic
Red as a beet blind as a bat dry as a bone mad as a hatter hot as a hare
which anticholingergic is the agent of choice in OB as it does not pass the placental barrier
glycopyrrolate
general dose of glycopyrrolate
0.1-0.2mg
onset of glycopyrrolate
duration of glycopyrrolate
onset rapid
duration 4 hours
benefit of glycopyrolate over atropine
less tachycardia than atropine
does glycopyrrolate cross the BBB
no
are CNS effects seen for glycopyrrolate like post op delirium that may be seen with atropine and scopolamine
no
compared to belladonna alkaloids what is the duration of glycopyrrolate
longer duration of action
triotropium (Spiriva)- classification
long acting inhaled muscarinic antagonist
spiriva (uses)
bronchodilator for patients with copd
benefits of triotropium (spiriva) (4 points)
improves lung function
improves quality of life
decreases exacerbations of copd
does not significantly reduce rate of decline in FEV1
scopolamine patch dose
1.5mg behind ear
scopolamine patch onset
4 hours
scopolamine duration
3 days
scopolamine patch instructions
dont touch your eyes
scopolamine compared to atropine CNS effects
CNS effects are much more pronounced at lower doses
scopolamine diminishes the incidence of …
post op n/v
what drugs are tertiary amine
what does being a tertiary amine mean the drug can do?
scopolamine and atropine
it means it can cross the BBB
belladonna alkaloid are which two drugs
scopolamine and atropine
