CCB ppt Flashcards
what is the role of intracellular Ca++
regulates contraction
how can you tell a myocyte cell from the rest?
it has troponin c
how does Ca++ work in cardiac muscle
Ca++ binds to troponinC releives troponin I inhibition of actin-myocin interaction
how does Ca++ work in smooth muscle
binds to calmodulin causing actin and myosin interaction
where is most Ca++ at intracellular or extracellular?
extracellular
where is most of the Ca++ at intracellularly
the SR
Ca++ bound to SR is what
inactive
Free Ca++ inctracellular concentration is markedly increased when?
during contraction b/c SR releases Ca++ and the Ca++ channel is open allowing Ca++ in
what are the 6 types of Ca++ channels
L N P Q R T
What are the Ca++ channels we deal with ?
L
and
T
what type of channels are Ca++ channels
voltage gate
what is a voltage gated channel
when they reach a voltage then the open
a ligand gated is a drug or hormone binding
what is the L-type channel
sustained conductance, slow inactivation
What is T-type channels
similar to L but rapid inactivation’have minimal sensitivity to CCB
with CCB what type of channel are me using the most
L-type
5 subunits of L-type (slow) Ca++ channels
alpha 1 alpha 2 beta gamma delta
3 main types of CCB then what are the real way to differentiate them into 2 goups?
Non-dihydropyridines
-Phenylalkylamines-
-Benzothiazepines-
1,4- dihydropyridines (DHPs)
so basically all CCB are DHP except for what 2 drugs?
verapamil
and
diltiazem
what is an example of a NonDHP phenylaklylamine and benzothiazepines
phenylaklylamine- verapamil
benzothiazepines- diltiazem
a way to try and remember
(benz=lorazepam sounds like diltazem)
what is the main difference b/t NonDHP and DHP?
Non-DHP-affect nodes (both verap and diltaz)
DHP-do not effect Nodes
how do phenylalkylamines work?
Verapamil
binds to intracellular portion of alpha subunit 1
how do benzothiazepines work
diltiazem
MOA not understood
how do DHP work
modulate the L-type channel
vascular smooth muscle
should someone be on cardizen and a BB?
no b/c they both affects nodes
can someone be on a BB and DHP CCB
sure the DHP CCB don’t effect HR
******************************** out of the drugs Verapamil Non-DHP (phenylalkylamine) Diltiazem Non-DHP (benzothiazepine) Nifidipine DHP Nicardipine DHP which ones in order cause coronary vasodilation
Verapamil- moderate
Diltiazem - mod
Nifidipine - marked
Nicardipine ** greatest
********************* out of the drugs Verapamil Non-DHP (phenylalkylamine) Diltiazem Non-DHP (benzothiazepine) Nifidipine DHP Nicardipine DHP whcih ones in order cause supression of cardiac contractility
Verapamil-moderate
Diltiazem -mod
Nifidipine - mod
Nicardipine -0/slight
****************** out of the drugs Verapamil Non-DHP (phenylalkylamine) Diltiazem Non-DHP (benzothiazepine) Nifidipine DHP Nicardipine DHP which ones in order cause supression of SA node
Verapamil -mod
Diltiazem - slight
Nifidipine - none
Nicardipine - none
************ out of the drugs Verapamil Non-DHP (phenylalkylamine) Diltiazem Non-DHP (benzothiazepine) Nifidipine DHP Nicardipine DHP which ones in order cause supression of AV node
Verapamil - marked
Diltiazem - mod
Nifidipine - none
Nicardipine - none
ex of DHP CCB
Nicardipine nifedipine nimodipine clevidipine amlodipine (-pine) (remember Ca++le graze in the -pine)
pharmacology of Non-DHP
Neg inotropic
Neg- chronotropic
Neg-dromotropic
positive- Lusitropic (myocardial relaxation)
what do ALL CCB do pharmacology wise
- decrease coronary vascular resistance and increase coronary blood flow
- Decrease PVR via vasodilation of arterioles
- minimal venous tone effects
which CCB is best for variant angia
eg vasospastic or prinzmetal’s angina
Narcardapine
which CCB is good for subarachnoid hemorrhage (posthemoragic cerebrovascular spasm
Nimodipine
which CCB’s are good for Hypertrophic cardiomyopathy
Nifidipine
verapamil
Common SE of CCB
-orthrostatic hypotension
-bradycardiam(DHP increase HR)
- periphreal edema
- dizziness
headaches
flushing
N/V
Verapamil can increase the levels of what drug
Digoxin
which CCB is commonly used in the OR Can be given bolus or infusion and what class
Nicardapine
DHP
Which CCB is very fast onset off set, faster than nicardapine, prepared in a lipid emulsion, only given in bolus no infusion?
Clevidipine
Contraindications to Verapimil
WPW
Sicksinus syndrome
Av block
Heart rate
how do CCB decrease contraction
decrease influx of Ca++ causes decrease in contraction
**** basic way Non-DHP work
slow cardiac conduction
decrease HR via SA and AV nodes
basic way DHP work
no effect on conduction
vasodilate
increase HR
what CCB is the greatest coronary vasodilator and can cause coronary steal?
Nicardapine
Why are DHP and BB ok to use in combination
DHP incease HR and BB decrease HR
why do Non-DHP slow HR
closes the Ca++ channels in phase 4 thus decreasing hr
so it basically blocks the conduction and prolongs the time it takes to reah the threshold
If HR is 45 and B/P is 210/105 what drug would you give
DHP like nicardapine or any
if has no effect on HR and will decrease BP
