Pharmacology Flashcards
CSF absorption requires lipid soluble vs insoluble? ionized vs nonionized?
lipid-soluble. nonionized.
how many half lives to reach steady state?
5.
meaning of tachyphylaxis?
tolerance after only a few doses.
drug metabolism via liver p450.
phase I. demthy/ox/redux/hydrol reactions… NADPH/oxygen required.
phase II. glucuronic acid and sulfates attach to make water soluble
p450 inhibitors
cimetidine, isoniazid, ketoconazle, erythromycin, cipro, flagyl, allopurinol, verapamil, amiodarone, MAOIs, disulfuram
p450 inducers
cruciform vegetables, ETOH, cigarettes, phenobarbital, phenytoin, theophylline, warfarin
urate crystals on microscopy
negative birefringent (yellow, needle shaped)
podagra?
1st MTP joint gout; MC area effected.
colchicine MOA
binds tubulin and inhibits migration CHEMOTAXIS of WBC in gout
allopuriol MOA
xanthine oxidase inhibitor; blocks urate from xanthine.
probenecid MOA gout
increase renal secretion of uric acid.
niacin MOA
inhibits cholesterol synthesis; can cause FLUSHING.
statin MOA
HMG COA REDUCTASE INHIBITOR
alvimopan MOA
binds and inhibits mu-opioid receptor for postop ileus.
zofran MOA
serotonin (central) receptor inhibitor.
promethazine and metoclopramide MOA
DA receptors; increase gastric and gut mobility
what agent improves survival in CHF?
ACEi
what agent improves survival after MI?
Bblocker.
highest MAC?
nitrous oxide NO2; low potency = high MAC = fastest!
malignant hyperthermia MOA?
ryanodine receptor defect… mucsle excitation from Ca release
after succinylcholine (IRREVERSIBLE).
malignant hyperthermia sx?
increased end tidal, fever, tachycardia, rigidity, acidosis, hyperkalemia, rhabdomyolysis
mgmt malignant hyperthermia?
dantrolene (10 mg/kg) inhibiting Ca release and decouples complex
cool, bicarb
glucose
supportive care.
succinylcholine and hyperkalemia
causes more; (depol = release K)
so avoid in: burn, neurologic injury, neuromusclar disorders, SCInjury, trauma, renal failure)
Hoffman effect?
degradation of drug in blood spontaneously.
nimbex.
metabolism of rocuronium, vec, pan
roc/vec: hepatic
pan: renal
nondepol MOA
compete with ACh
reverse nondepolarizing roc?
sugammadex: selective binding to paralytic…. to reverse roc and vec
neostigmine/edrophonium: block Achase to increase ACh.
with atropine/glycopyrrolate to reverse overwhelming ACh.
MOA local
increase action potential threshold preventing Na influx into neuron
dose of local anesthetic?
0.5 cc/kg of 1% lidocaine.
max dosing lido and bup
lido 4 mg/kg
bup 2 mg/kg
SE of meperidine demerol?
tremors, fasciculations, seizures (normeperidine) avoid in RENAL FAILURE.
but it also is used to treat postop shaking
contraindication to epidural and spinal anesthesia?
hypertrophic cardiomyopathy, cyanotic heart disease (sympathetic denervation can cause decreased afterload which worsens conditions).
epidural location for different thoracotomy vs laparotomy?
thoracotomy: T6-T9
laparotomy: T8-T10.
T5 = affects cardiac accelerator nerves
spinal anesthesia location?
L2 to avoid spinal cord (subarachnoid)
LR composition
Na 130
K 4
Ca 2.7
Cl 109
lactate 28 (converts to HCO3- in body though)
NS vs HTS?
Na 154 … 513
Cl 154 … 513
calculate plasma osmolarity?
2Na + glucose/18 + BUN/2.8.
normal 280-295.
fluid loss in major abdominal operations?
0.5-1L/hr.
gastrointestinal losses by organ per day?
stomach 1-2L
biliary system 0.5-1L
pancreas 0.5-1L
duo 0.5-1L
hyponatremia
FW restriction and NS
no more than 1 mEq/hr (8 per day) otherwise central pontine myelinosis
DI
decreased ADH… lots of diluted urine, hypernatremic, high serum osm
etiology: head injury
treat: DDAVP (or free water if chronic)
SIADH
increased ADFH… minimal concentrated urine, hyponatremic, low serum osm
etiology: head injury, carbamazepine, SSRI, cyclophosphamid, cipro, haldol, amiodarone, vincristine, vinblastine, cisplatin, bromocriptine
treat: conviaptan, tolvaptan
chronic: slow diuresis and fluid restriction
protein adjustment for calcium
for every 1 g decrease in protein, add 0.8 to Ca
vit D metabolism
made in skin 7DHC to cholecalciferol goes to liver for 25 OH and then kidney for 1 OH (active)
flumazenil dosing
0.2 mg over 30 seconds
repeat up to 3 mg
hofman elimination
not cleared by liver
renal excretion narcotics
yes: morphine, oxy, tramadol, hydrocodone
no: dilaudid = hydromorphone, fentanyl, sufentanil,
spinal anesthesai
into intrathecal space
vasopressin receptor
V1
vasoconstrict and inhibit NO release via IL-1 and NO synthease
where is tetracycline and heavy metals stored
BONE
0 order kinetics
CONSTANT amount eliminated regardless of dose
1st order kindetics
drug eliminated proportional to DOSE
how many half lives tilsteady state
5
metyrapone and aminoglutethimide
inhibit adrenal steroid synthesis in adrenocortical carcinoma
leuprolide
GnRH and LHRH analogues
inhibit LH and FSH release from pituitary…. for metastatic prostate ca
tamsulosin
alpha-receptor ANTAGONIST for BPH
misoprostol
PGE1 deriviative; PGE1 is GOOD! so protective prostaglandin…..
decrease PUD, consider in chronic NSAID use that is causing ulcers
halothane
SLOW on/off… HIGH cardiac depression. smells good though.
SE: halothane hepatitis… fever, eosinophilia, jaundice
isoflurane
for NSY… pungent decrease brain O2 consumption
sevo
good for mask; fast. less laryngospasm
enflurane
causes seizures
MAC and potency
small MAC = more lipid soluble = MORE potent
speed of induction goes up with solubility
so high MAC = less soluble = fast induction
propofol metabolism
liver & pseudocholinesterases
esters vs amides allergy
esters (I at the end only) ….cause allergy from PABA analogue
versed in pregnancy
aVOID; crosses placenta
