ANS Pharm: ACEIs, ARBs, Anesthetic Agents Flashcards
dry cough from ACEI
Which effects of the volatiles are:
ANS mediated?
spinal cord mediated?
- ANS: amnesia, sedation, unconsiousness
- spinal cord: immobility (MAC)
Which locals are antiarrhythmics?
1A: procainamide
1B: Lidocaine
RAAS starts with renin secretion by renal cortical juxtaglom. cells. What causes this?
decreased renal perfusion d/t hemorrhage or SNS activation
synthesizes angiotensinogen
liver
renin acts on ___ to produce ___
cleaves angiotensinogen to produce angiotensin 1
Angiotensin 2 is a potent vasoconstrictor of kidney and mesenteric arterioles via its action on….
the angiotensin receptor, type 1 (AT 1).
angiotensin receptor, type 2 (AT2)
regulates vascular response, cardiac growth response, and fibrotic response in other tissues
type 1: angiotensin 2 acts there to vasoconstrict
RAAS
role in HTN
- HTN involves RAAS dysfxn
- RAAS modules NT release (influences SNS outflow)
Actions of angiotensin II
- triggers release of norepi & epinephrine from the adrenal medulla
- acts on renal tubules to decrease both Na & water elimination while increasing K excretion.
- stimulates Aldosterone production (amplifies Na retention & K excretion)
T/F:
The result of RAAS is an elevation of venous blood pressure and an increased intravascular volume.
false
arterial BP
RAAS
Which hormones come from the adrenal cortex vs the medulla
cortex: aldosterone
medulla: epi, norepi
T/F:
Angiotensin 1 and 2 cause vasoconstriction.
False
only 2
Although ACEi drugs are potent, they are devoid of the many side effects of other antihypertensives such as…
bradycardia, bronchospasm, and rebound hypertension when acutely discontinued
ACEi drugs are best for HTN from increased renin & are first-line therapy for…
HTN, CHF, mitral regurgitation, LV dysfunction
ACEI effects
- Decrease angiotensin (↓ aldosterone)
- Reduce LV afterload
- reduce arterial tone
- ↓ water and Na retention
- decrease bradykinin breakdown (endogenous vasodilator)
- lowers LDL
- Do not impair baroreceptors, thus orthostatic hypotension is not an issue.
- renal protection in diabetics
ACEI prevent bradykinin breakdown. This contributes to 2 important side effects
cough
angioedema
ACEIs + vasodilating GA can cause hypoTN that is not responsive to …., so use ___
neo, ephedrine, norepi
use vaso (V1)
ACEIs can cause renal dysfxn and this electrolyte imbalance
hyperK
my also see fatigue
Which ACEI is a prodrug?
Which ACEI is excreted unchanged in the urine?
lisinopril
T/F:
Angioedema from ACEIs is thought t be genetically linked.
True
Black people 4.5x more likely
the only ACEI available IV
enalapril
Why do ARBs have less SEs than ACEIs?
ACEI impair activity at both AT 1 & AT 2 receptors
ARBs only AT1 receptor (more selective)
ARBS have similar SE to ACEi but milder and no dry cough
primary outcome is also similar
ARBs receptor activity
- great affinity for AT1r
- inhibit angiotensin 2 @ AT1r
- better at inhibiting angiotensin 2 than ACEi
T/F:
ACEi provides renal protection for DM, unlike ARBs.
False
both can
T/F:
Volatiles have anti-seizure activity.
True
primary inhibitory & excitatory NT in CNS
GABA
glutamate
common anesthetics that enhance GABA
- volatiles
- prop
- etomidate
- BZDs
- Barbs
What explains the CV, respiratory and neuroendocrine effects of anesthetics?
they alter neurotransmission
GABAr structure
ligand gated ion channel
Cl- influx hyperpolarizes = inhibits neuronal cells
ANS modification by volatile inhaled agents:
- ↓ BP, CO, Cl, SVR
- ♡ depressant & vasodilates (Alters Ca fxn)
- Depress baroreceptor reflex (HD instability)
- Antagonizes SA node automaticity (nodal rhythm) & prolong QT interval (inhibition K efflux which repolarizes)
- Impairs ventilatory response to CO2 and O2. Low Minute ventilation for a given blood gas tension.
- Uncoupling of cerebral blood flow autoregulation (> 0.5 MAC).
Volatiles primary receptor target
GABAA
Volatiles uncouple CBF autoregulation, usually above 0.5 MAC. What does this mean?
- blood flow will be higher than metabolic need
- the ability to maintain a consistent blood flow despite changes in blood pressure is disrupted
Which anesthetics target GABA A?
- volatiles
- Propofol
- Etomidate
- BZDs
T/F:
Etomidate blocks the SNS response to laryngoscopy.
True
How does etomidate affect CBF?
cerebral vasoconstrictor
reduces CBF & ICP
Ketamine is a/w CV stability and works to treat depression and pain. What are the limiting SEs?
- emergence delirium
- secretions
- nystagmus
- hallucinations
Precedex can decrease MAC by how much?
over 90%
Lidocaine is a class 1B antiarrhythmic. How do they work?
- suppress automaticity by increasing stimulation threshold of the ventricle & His-Purkinje
- inhibiting spontaneous depolarization during diastole
longest doA LAs
bupi & ropi
most potent LA
tetracaine
followed by chloroprocaine, bupi, ropi
What rhythms can lidocaine treat?
- AFIB
- PVCs
- VTach
fast onset LAs
- lidocaine
- chloroprocaine
- cocaine
Why is cocaine unique as a LA?
increases endothelin (vasconstrictor)
&
impairs nitric oxide production
renin
