Pharm Unit 3: Aspiration/PONV, Antiarrhythmics, Fluids, LA, Abx (FINAL) Flashcards
What types of drugs are used for aspiration prevention
H1 blockers
H2 blockers
PPI’s
Dopa receptor antagonists
H1 blockers MOA
decreased contraction of intestinal smooth muscle
H1 blockers uses
sedation
decreased GI motility
antimuscarinic
what is the H1 blocker
diphenhydramine
H2 blockers MOA
decrease acidity of gastric acid
H2 blockers uses
ulcers
GERD
H2 blockers common drugs
“tidine”
ranitidine
famotidine
nizatidine
cimetidine
PPI MOA
inhibit acid secretion
PPI uses
ulcers, GERD
PPI common drugs
“prazole”
pantoprazole
omeprazole
lansoprazole
dopamine receptor antagonist MOA
increase LES tone
increase GI motility
dopamine receptor antagonist uses
GERD
diabetic gastroparesis
dopamine receptor antagonist adverse effects
acute dystonic reaction
common dopamine receptor antagonist
metoclopramide
5HT3 antagonists MOA
block serotonin
- peripherally: vagal nerve terminals
- centrally: chemoreceptor trigger zone
5HT3 antagonists uses
emesis due to vagal stimulation
5HT3 antagonists adverse effects
QT prolongation
5HT3 antagonists contraindications
pts w/prolonged QT interval
use w/ drugs that inhibit CYP enzymes
common 5HT3 antagonists
“setron”
ondansetron
granisetron
dolasetron
palonosetron
antimuscarinics uses
motion sickness
PONV
antimuscarinics adverse effects
dry mouth
blurry vision
cognitive impairment
common antimuscarinic for PONV
scopalamine patch
D2 receptor antagonist MOA
block D2 receptor in CTZ
D2 receptor antagonist adverse effects
acute dystonic reaction
prolonged QT
D2 receptor antagonist common drugs
“peridol”
droperidol
haloperidol
“azine”
perphenazine
promethazine
prochlorperazine
Neurokinin receptor antagonists MOA
inhibits substance P
Neurokinin receptor antagonist drug
Aprepitant
dexamethasone adverse effects
perineal burning, impaired glucose tolerance
Class IA antiarrhythmics
Quinidine
Procainamide
Disopyramide
Class IA antiarrhythmics MOA
block VG Na+ and VG K+ in myocytes
quinidine indications
PVC’s
Systained VT/VF
Afib/Aflutter
short QT syndrome
quinidine adverse effects
N/V
diarrhea
tinnitus/hearing loss
hypotension
QRS & QT prolongation, torsades
quinidine contraindications
prolonged QT
Procainamide Indications
sustained VT, Afib in WPW
procainamide adverse effects
rash, myalgia, vasculitis, hypotension, bradycardia, QT prolongation, torsades, drug induced lupus
Procainamide Contraindications
prolonged QT
disopyramide indications
PVC’s, VT
Afib
dispyramide adverse effects
urinary retention, constipation, glaucoma, QT prolongation, torsades
disopyramide contraindications
prolonged QT
Class IB Antiarrhythmics
Lidocaine
Mexiletine
Class IB Antiarrhythmics MOA
block VG Na+ in myocytes
Class IB Antiarrhythmics indications
V tach, V fib
Class IB Antiarrhythmics adverse effects
increased potency in ischemic tissue, GI effects
lidocaine SE
visaul disturbances
tremor
seizure
drowsiness
hallucination/coma
asystole
hypotension
N/V
Mexiletine SE
GI upset
N/V
blurred vision
tremor
headache
ataxia
confusion
Class IB Antiarrhythmics contraindications
atrial tachyarrhythmias, HF/liver disease
Class IC antiarrhythmics
Flecainide, Propafenone
Class IC antiarrhythmics MOA
dramatically prolong phase 0 in myocyte AP (block VG NA+)
Class IC antiarrhythmics indications
AFib (w/o CAD), SVT
flecainamide adverse effects
dizziness, dyspnea, headache, blurred vision, nausea, HF exacerbation, AV block, VT/VF in pt’s with CAD
flecainamide contraindications
heart failure
CAD
propafenone adverse effects
dizziness, dyspnea, headache, blurred vision, nausea, bradyccardia
bronchospasm
propafenone contraindications
heart failure
CAD
asthma
Class II antiarrhythmic drugs
beta blockers
beta blockers MOA
decreased slope of phase 4 depolarization
prolong depolarization at AV node
beta blocker indications
Afib/Aflutter (slow HR down)
SVT’s
ventricular arrhythmia prevention
will not convert back into normal sinus
beta blocker adverse effects
fatigue
hypotension
bronchospasm
mask hypoglycemic symptoms
aggravation of heart failure
Class III antiarrhythmics
Amiodarone
Class III MOA
K+ blocker
– prolongs QT interval
Class III SE
torsades the pointes
higher proarryhthmia risk
Amiodarone MOA
K+ blocker (high)
- prolongs AP duration
- phase 3
Na+ blocker
Ca2+ blocker
beta blocker (slow SA/AV conduction)
when does amiodarone work best?
at high heart rates due to use-dependence
amiodarone indications
VT/VF
SVT
Afib/Aflutter
amiodarone features
lg volume of distribution due to lipophilicity
requires loading dose (10g)
delayed onset
long half life (2 months)
amiodarone adverse effects
pulmonary toxicity
liver injury
hypotension
bradycardia
AV block
worsening dysrhthmias
thyroid abnormalities
amiodarone contraindications
hypersensitivity (iodine)
cardiogenic shock
bradycardia
AV blocks
amiodarone drug interactions
digoxin
warfarin
statins
amiodarone metabolism
hepatic by CYP3A4 and 2C8
amiodarone inhibits
CYP3A4
CYP2C9
P-glycoprotein
Class III drugs that can cause torsades
dofetilide
sotalol
dronedarone compared to amiodarone
less efficacy than amiodarone
does not contain iodine
dronedarone SE
GI impacts
dronedarone indications
atrial flutter
afib
Class IV antiarrhythmics
non-DHPR CCB’s
verapamil
diltiazem
non-DHPR CCB MOA
inhibition of L-type Ca2+ channels (phase 0 in nodal tissue)
slow depolarization in pacemaker cells
non-DHPR CCB indications
SVT
Afib/Aflutter
non-DHPR CCB adverse effects
hypotension
bradycardia
AV block
decreased SV
adenosine adverse effects
dyspnea
bronchospasm
flushing
chest pressure
Adenosine indications
SVT
digoxin MOA
increases parasympathetic tone via vagus nerve
– decr sinus node
– prolongs AV node refractory
inhibits Na/K-ATPase pump
–incr Ca2+
–incr contractility
–incr proarrhythmic potential
digoxin indications
atrial fibrillation
aflutter
heart failure w/ reduced EF
digoxin CI
afib
aflutter
WPW
digoxin adverse effects
narrow therapeutic window
GI upset
halo vision
malaise
bradycardia
AV block
VT/VF
when is digoxin used?
on a resting heart rate
– pt is just sitting not walking around
rate control in combination with BB/CCB
Antimuscarinics indications
bradycardia
AV block
antimuscarinic side effects
dry mouth
blurry vision
photophobia
tachycardia
antimuscarinic drugs
atropine
glyco
antimuscarinic MOA
block ACH from binding to muscarinic receptors
alters parasympathetic response
anti-parasympathetic drugs
preop causes of volume derangements
bowel preps
bowel obstruction
pancreatitis
blood loss
anesthetic causes of volume derangements
anesthetic hypotension
(vasodilation)
sympathetic blockade
surgical causes of volume derangements
hemorrhage
coagulopathy
decreased venous return
long operative time
when is hypervolemia clincally significant
> 10% above basewline
hypervolemia SE
incr morbidity
tissue edema
impaired wound healing
pulm edema
decr GI motility
what lab value reflects total body water status
serum sodium
what content in IV fluid dictates fluid distribution?
Na+
what factors influence total body water content
gender
age
nutritional status
disease state
TBW and age relationship
less water with increased age
neonates TBW
70-80% of body weight is water
calculating TBW
50-60% of body weight
ICF:ECF
2:1
2/3 ICF and 1/3 ECF
ECF
interstitial fluid (3)
plasma (1)
ISF: plasma = 3:1
electrolyte content of ECF
Na+
Cl-
electrolyte content of ICF
K+
Phosphate
what is colloid osmotic pressure
pulls fluid into vessels
what maintains fluid components of blood within vessels?
colloid osmotic pressure (oncotic pressure)
what changes oncotic pressure
allbumins
proteins
etc
what is hydrostatic pressure
pushes fluid out of vessels
what is osmolar force
push and pull in and out of vessels
what does lactate do in LR?
provides circulating bicarb to provide normal HCO3- levels during acidosis
???????
what is the main contributor of osmolarity
sodium
Tonicity of Crystalloids
isotonic
Distribution of water
ECF and ICF
distribution of saline/LR
distributes only to ECF
distribution of colloids
distributes only to intravascular space
colloid types
albumin
hetastarch
dextrans
HES SE
acute kidney
incr moprtaloity
incr need to PRBC transfusion
albumin
source of capillary oncotic pressure (80%)
types of albumin
hyperoncotic (25%)
5% albumin (isotonic to plasma)
pts low in albumin
nutritionally deficient
renal disease
liver disease
most potent colloid
25% albumin
Hetastarches (HES)
amylopectin and synthetic glycogen
HES molecular weight
high MW = slower degradation
Dextrans
long chains of glucose (polysaccharides)
Dextran unique property
rhological properties
– moderate plt function
– antithrombotic
used in vascular sx to prevent post-op stroke
typical water loss per day
2.5 L/day
causes of increased water loss
fever
sweating
gastric
colon
insensible losses
normal Na loss
77 mEq/day
normal K loss
40-60 mEq/day
normal Cl loss
same as sodium
where will LR/Saline distribute
ECF- 1/4 IV 3/4 IS
where will D5W distribute
ECF and ICF proportionally
where will Albumin distribute
intravascular space
best fluid for maintenance
D5W + 0.225% NaCl
best fluid for metabolic acidosis
LR
preferred IVF in anesthesia
LR
which colloid solutions have a risk for bleeding
6% hetastarch, Dextran 40
how to calculate total body water
0.6L/kg
N/S SE
hyperchloremic acidosis
reduction of renal perfusion
water distribution
across all compartments
vascular compartment
Interstitial space
cell membranes
Na+ distribition
capillary membrane
interstitial fluid
pumped out of cell
colloids distribution
confined to vascular compartment
does not cross into capillary membrane
crystalloids use
mx
replacement of losses
treatments of symptoms
– fluid or electrolyte deficits
colloids uses
add oncotic pressure
volume replacement
rheologic propoerties
sensible loses
measurable
insensible losses
respriation
fever
evaproration (surgical)
adult fluid maintenance
30mL/kg/day
minimal losses
0-2 mL/kg
moderate losses
2-4 mL/kg
severe losses
4-8 mL/kg
what fluid dosing is recommended during major invasive surgery?
zero balance approach
- only fluid lost is replaced
mechanism of action of local anesthetics
Block voltage-gated sodium channels
what does Blockage of voltage-gated sodium channels do
blocks generation and conduction of action potentials
when do local anesthetics gain access to Na channels
during activated state
when is the affinity of LA for Na channels greater
when Na channels are open
what does the lipophillic region of LA affect
onset of action
potency
duration
increasing lipophilicity
increases potency
slower onset
what does ester or amide linkage of LAs affect
duration of action
if someone has an allergy to amid local anesthetics, can you safely give an ester?
yes (& vice versa)
what does a higher % neutral affect
enhanced absorption
how does % neutral affect absoprtion
neutral form penetrates the membrane
what do we want the pKa of the LA to be
closest to physiologic pH
what is the determining factor for LA toxicity
vascularity
Vascularity ranking Highest to lowest
HIGH
IV
tracheal
intercostal
caudal
paracervical
epidural
brachial plexus
subarachnoid/sciatic/femoral
subQ
LOW
what does the risk for systemic LA toxicity depend on
lipid solubility
amount of connective tissue in area
pH of tissue
% neutral
is epi added?
how does lipophilicity and tissue protein binding affect duration
remains in tissue longer
how does epi affect the LA
makes LA more acidic
what does bicarb addition to epi + LA
makes it neutral for a faster onset
what delays LA redistribution
vasoconstriction
why is epi added to local?
prolongs duration of action
reduced peak serum concentration
onset of LA: lipid solubility
less lipid soluble = less potent
(typically delays onset)
duration of action of LA
potency
lipid solubility - more = slower diffusion = longer DOA
what type of axon is more sensitive to LA blcok
myelinated
what is the most common feature of LAST
seizures
what does a low CC/CNS ratio mean
more cardiotoxic
what does a high CC/CNS ratio mean
more CNS toxiv
what type of pt is at increased risk for LAST
pregnant elderly
neonate
how to treat LAST
lipid emulsion 20% IV, 100 ml bolus over 2-3 min
rebolus 200 mil over 15-20 in
Lidocaine maximum dose
4.5 mg/kg
Lidocaine + Epi maximum dose
7 mg/kg
ropivacaine max dose
2.5 mg/kg
bupivacaine max dose
2.5 mg/kg
lidocaine pKa
7.6
ropivacaine/bupivacaine pKa
8.1
how does pKa affect onset
pKa closer to physiologic pH = higher % neutral, faster onset
which local anesthetics can cause methemoglobinemia
prilocaine and benzocaine
which local anesthetics are more cardiotoxic
bupivacaine
which local anesthetics are more CNS toxic
mepivacaine
what does extreme lipophilicity promote
continued binding and increased duration of action
LA that is extremely lipophilic
bupivacaine
what LA property does protein binding affect
duration of action
what LA property does pKa affect
onset of action
what correlates with toxicity risk
Cmax
time to Cmax
what drugs could be used to manage LA systemic toxicity
epinephrine, amiodarone
midazolam
lipid emulsion
What is the minimum inhibitory concentration (MIC)?
lowest concentration of a given antimicrobial that will inhibit an organisms growth
bacteriostatic
do not kill organism
interfere w/growth/replication
bacteriocidal
kill the organism
how is antibiotic susceptibility related to MIC
MIC increases with reduced susceptibility
when does resistance occur
when MIC exceeds the tolerable dose
What is the post-antibiotic effect?
Bacterial killing continues after the serum level drops below the MIC
what is time dependent killing
cidal activity continues as long as the concentration in plasma is greater than MIC
for a long surgery, what abx do you need to re-dose
time-dependent agents
what is an example of time dependent killing
beta lactams
what is concentration dependent killing
efficacy increases as concentration increases
examples of concentration dependent killling
aminoglycosides and quinolones
what type are antibiotics are typically bacteriostatic
protein synthesis inhibitors
characteristic of a bacteriostatic antibiotic
interfere with growth and replication
what is empiric therapy
treat based on most likely organisms
what type of antibiotics are typically bactericidal
cell wall acting
when are bactericidal abx always used
immunosuppressed or severe infection
definitive therapy
treat based on identified organism
preventative therapy
prophylaxis based on the most likely organism
post antibiotic effect
Persistent suppression of bacterial growth after antibiotic concentration has fallen below the specified MIC is known as
Antibiotic which may prolong the neuromuscular blocking effects of rocuronium
levofloxacin
When this agent is combined with ampicillin, it extends the spectrum of activity to be active against more gram negative and anaerobic bacteria
sulbactam
The mechanism of action of cefotetan is
inhibition of crosslinking of peptidoglycan to inhibit bacterial cell wall synthesis
Prolonged QT on ECG and cardiac arrhythmia is a possible risk with
quinolones
antibiotic to avoid in a pregnant patient
doxycycline
Agent that may be used for decolonization of patients who are nasal carriers of MRSA and MSSA
mupirocin
vancomycin is associated with all of the following adverse effects except
bleeding
Select the antiemetic agent that is associated with dry mouth, blurry vision, and may cause cognitive impairment in elderly patients:
scopalamine
An agent that may be useful for late or delayed nausea and vomiting:
palonosetron
Dexamethasone IV injection has been associated with:
perineal burning sensation
A patient treated with droperidol in the PACU develops an acute and painful cervical dystonic reaction. Select appropriate therapy to relive the dystonia
diphenhydramine or glycopyrrolate
Are beta lactams bactericidal or bacteriostatic?
bactericidal
beta lactams MOA
Inhibition of cell wall synthesis: Interference with peptidoglycan crosslinking
penicillins spectrum
G+, G-,
non-b lactamase anaerobes (broad spectrum) (streph/staph)
Penicillins: Adverse Effects
hypersensitivity reaction, seizure
difference between cephalosporins and penicillins
more stable against bacterial beta lactamase
1st gen cephalosporin
Cefazolin
1st gen cephalosporin coverage
gram positive, some gram negative
2nd gen cephalosporin
Cefotetan (also anaerobes)
cefoxitin
2nd gen cephalosporin coverage
gram positive, more gram negative
3rd gen cephalosporin
Ceftriaxone
3rd gen cephalosporin coverage
decreasing gram positive, increasing gram negative
4th gen cephalosporin
Cefepime
4th gen cephalosporin coverage
G+, G-, pseudomonas
5th gen cephalosporin
Ceftaroline
5th gen cephalosporin coverage
MRSA
cephalosporin adverse effects
allergy, bleeding, disulfiram reaction
beta lactamase inhibitors
Clavulanate (amoxicillin or ticarcillin/clav
Sulbactam (ampicillin/sulb)
Tazobactam (piperacillin/tazo)
beta lactamase inhibitors MOA
inactivate beta lactamase to make other abx more active
carbapenems
Meropenem, Ertapenem
Doripenem
carbapenems MOA
inhibit cell wall synthesis (resistant to beta lactamases)
Carbapanems spectrum
gram positive, gram negative
anaerobes
pseudomonas
Carbapenems adverse effects
seizure, renal impairment
beta lactamase inhibitors spectrum
G+, G-
anaerobes
vancomycin MOA
inhibits synthesis of cell wall precursors
D-Ala terminus inhibiting crosslinking
Vancomycin spectrum
Gram +: enterococcus
MRSA
C. Diff
what do we try to reserve vancomycin for?
MRSA treatment
Vancomycin adverse effects
nephrotoxicity
ototoxicity
red man syndrome
vancomycin infusion time
1 hr
avoids red man syndrome
is vancomycin a beta lactam
No
what drug is an alternative for penacillin allergies
vancomycin, macrolides
aminoglycosides
gentamicin
neomycin
amikacin
what drug is related to bowel prep or irrigation?
neomycin
aminoglycosides MOA
inhibit bacterial protein synthesis (30S subunit)
Are aminoglycosides bactericidal or bacteriostatic?
bactericidal
Aminoglycosides adverse effects
ototoxicity
nephrotoxicity
prolong neuromuscular blockade (NDMR)
macrolides
erythromycin
clarithromycin
azithromycin
macrolides MOA
inhibit protein synthesis (50S subunit)
macrolides spectrum
G+, pneumococci
macrolides adverse effects
GI effects, inhibit CYP 450
tetracyclines
Tetracycline, Doxycycline
Minocycline
tetracyclines MOA
inhibit protein synthesis (30S subunit)
inhibit adding next amino acid
Are tetracyclines bacteriostatic or bactericidal?
bacteriostatic
tetracyclines spectrum
Gram (+), mycoplasma, H. pylori, Chlamydia
tetracyclines adverse effects
GI altered flora
tetracyclines contraindications
pregnancy
causes bone deformities and teeth issue in fetus
clindamycin MOA
inhibit protein synthesis (50S subunit)
Is clindamycin bacteriostatic or bactericidal?
bactericidal
clinda spectrum
most gram pos
most anaerobes
Clindamycin adverse effects
C. diff, GI effects
oxazolidinones
Linezolid
oxazolidinones MOA
prevents formation of ribosome complex
23s ribosomal rna on 50s subunit
oxazolidinones spectrum
G+ (MRSA, VRE, VRSA)
vanc resistant enterococci
what do we reserve linexolid for
MRSA
vanc-resistant MRSA
oxazolidinones adverse effects
MAO activity (degrades catecholamines - HTN response)
hematological (anemia, thrombocytopenia)
neuropathy
DNA synthesis inhibitors
Quinolones
quinolones
Ciprofloxacin
Levofloxacin
Ofloxacin
lomefloxacin
perfloxacine
quinolones MOA
inhibit topoisomerase II (DNA gyrase)
inhibit topoisomerase IV
quinolones spectrum
Broad (G+ and G-)
do not cover anaerobes
Quinolones adverse effects
glycemia
QT prolongation
growing cartilage (CI for preg/peds)
tendonitics
enhance NMB
quinolones CI for what pts
pregnant
peds
antimetabolites (antifolates)
sulfonamides
sulfonamides MOA
inhibit folate synthesis
(inhibit purine/DNA synthesis)
sulfonamides spectrum
gram positives
sulfonamides adverse effects
megaloblastic anemia,
leukopenia
granulocytopenia
vasculitis
cross reactivity
metronidazole use
add when worried about anaerobes
when to use metronidazole
abdominal
absesses
mixed infection
mupirocin use
MRSA nasal colonization
polymixins use
bactericidal for abdominal procedures
when should the antibiotic be administered?
60 min prior to incision
when should vanc and quinolone be administered
120 min prior to incision
when should you give cefazolin?
30 mins prior
when do you redose abx
sx longer than 4 hrs
major blood loss
how long do you mx prophylaxis of abx
duration of sx
not greater than 24 hrs
what is commonly used when there is a PCN allergy
vancomycin, clindamycin, erythromycin
what abx do you give for b lactam allergy
vancomycin
clindamycin
abx that impact NMJ (slower reversal)
aminoglycosides
quinolones
polymyxins
tetracyclines
clindamycin
reversal of abx NMB prolongation
calcium
neostigmine (not polymixin)
pt allergic to penicillin: what do you avoid?
penicillin
cefaclor
cefadroxil
cefatrizine
cefprozil
cephalexin
cephradine
can you use cefazolin w/penicillin allergy
yes
what drugs should you avoid in pregnancy in third trimester
TMP/SMX
- displace bilirubin from albumin
what drug should you avoid in all trimesters?
doxycycline
tetracycline
quinolones
SCIP
quality measures to medicare for public display