UWorld Day Three Flashcards
Demyelination of a nerve directly decreases ___. Directly increases ___.
Decreases the length constant (the distance the impulse can travel).
Increases the time constant.
Fever, tinnitus, tachypnia, and an empty pill bottle - what was ingested and what ABG toxicity?
Aspirin toxicity (two steps).
- Respiratory alkalosis - salicylates directly stimulate the medullary respiratory center, causing hyperventilation.
- Anion gap metabolic acidosis - salicylates increase lipolysis, uncouple oxphos, and inhibit TCA –> accumulation of organic acids in blood (ketoacids, lactate, pyruvate).
What would the ABG (pH, PaCO2, HCO3) be 4-5 hours after aspirin toxicity?
normal range pH low PaCO2 (respiratory alkalosis and compensation for metabolic acidosis) low HCO3 (metabolic acidosis)
Name the etiology and MOA:
A person ate sushi and presents with dizziness, weakness, loss of reflexes, paresthesias of face and extremities, N/V/D.
Tetrodotoxin from puffer fish binds to VGSC in nerve and cardiac tissue and prevents Na influx and depolarization.
TPR in parallel v. in series for R1, R2, R3, R4
In parallel: 1/TPR = 1/R1 + 1/R2 + 1/R3 + 1/R4 —> TPR = 1/(total added)
In series: TPR = R1 + R2 + R3 + R4
Antiepileptics with MOA of:
- inhibiting presynaptic VGCaC
- disrupting vesicle fusion
- blocking VGNaC
- Gabapentin
- Leviteracitam
- Phenytoin and carbamazepine
A middle age man with SOB, elevated liver enzymes, and no history of smoking or alcohol.
Alpha-1 Antitrypsin. Panacinar emphysema with cirrhosis due to build up of AAT in liver.
Morphine MOA
opioid. Morphine binds to mu-receptors, activating K-efflux, which hyperpolarizes and blocks pain conductance.
lanosprazole
PPI (same as omeprazole)
sx: PSVT
Admin ___ drug with AE of flushing, burning in chest, hypotension, AV block, SOB
adenosine - suppresses Ca influx.
Nitroglycerine (AHF and severe HTN) does what to levels of:
LVEDP
Venous capacitance
Systemic Vascular Resistance
decrease
increase
decrease
MOA of sulfonylureas and meglitinides
DM - increase insulin release (so increase C-peptide)
What two drugs decrease hepatic glucose production and increase sensitivity to insulin?
Metformin and rosiglizazone
Why take nitrates NOT around the clock?
because tolerance formation
Drugs involved in anti-histone ab presence
SHIPP-E: Sulfa-drugs, Hydralazine, INH, Procainamide, Phenytoin, Etanercept (TNF-alpha inhibitors)
Due to acetylation
Hyperphosphatemia, hypocalcemia, hyperK, hyperuricemia. Give what two drugs to decrease uric acid buildup during chemo-induced cell breakdown
hydration, allopurinol and rasburicase
HypoK –> mm weakness and arrhythmias, shake and bake, type 1 RTA. What drug toxicity. (Histo infxn)
Amphoterecin B
- Two causes of angioedema (1 drug, one genetic) due to bradykinin buildup.
- Two causes of angioedema due to mast cell activation.
- Sx Difference between mast cell activation and bradykinin.
ACE inhibitors, C1 inhibitor deficiency –> NO PRURITIS OR URTICARIA
Type 1 HSR, IgE mediated and direct mast cell activation –> PRURITIS AND URTICARIA
SE of what:
adipose - Lipolysis, altered fat distribution
adrenal cortex - atrophy
bone - osteoporosis
immune - suppression, T cell apoptosis
liver - increased gluconeogenesis and glycogenesis (LARGEST INCREASE IN PROTEIN SYNTHESIS)
skeletal muscle - atrophy
skin - thinning, stria, impaired wound healing
glucocorticoids
Difference between competitive and noncompetitive antagonists on graph.
- Competitive cause graph to shift right, meaning higher concentrations of agonist can have same biological effect.
- Noncompetitive antagonists cause the competitive agonist curve to lower in biological activity because regardless of agonist concentration, its effects are blocked.
__ = amount of drug given (mg) / plasma concentration of drug (mg/L)
Volume of distribution (L)
What type of volume of distribution (low or high):
- high molecular weight, high plasma protein binding, high charge, hydrophilicity
- small molecular weight, uncharged (lipophilic or hydrophobic)
- Low Vd because drug trapped in plasma compartment
2. High Vd because can cross easily through cell membrane into intracellular compartment
COX-2 selective inhibitor (only inflammation).
AE
celcoxib
AE is thrombosis bc TXA2 (causes platelet aggregation) is dependent on COX-1 and thus, not inhibited.
Calcium plays what role in vasculature?
So give CCB after what?
Causes vasoconstriction
Give CCB after a SAH to prevent cerebral vasospasm.
Always use ___, even if HDL is low.
MOA
Do not administer wtih what type of drugs?
Use a statin to lower LDL (not niacin to increase HDL) - because statins decrease risk of CV event.
Stains inhibit HMG-CoA Reductase
Do not administer with drugs that inhibit CYP34A
What lipid lowering therapy decreases serum TGs most? Primarily used to prevent pancreatitis in people with high HDL.
MOA?
fibrates
MOA - activates transcription factor PPAR to increase lipoprotein lipase activity
When do you give ezetimibe?
When person cannot take statin due to myopathy or hepatotoxicity.
What drug inhibits Na/K ATPase pump, which increases Na intracellularly, promoting Ca influx through Na(out)/Ca(in) and increasing myocardial contractility?
Digoxin
dobutamine - what type of drug?
Beta 1 adrenergic agonist. So Gs, increasing cAMP and increasing cytosolic Ca, increasing myocardial contractility.
Biologic agents:
- mab =
- cept =
- nib =
monoclonal ab (i.e. rituximab) receptor molecule (i.e. etanercept) kinase inhibitor (ie. imatinib)
Open angle glaucoma (Increased IOP) drugs (three classes):
____ diminishes aqueous humor secretion by ciliary epithelium
____ decreases aqueous humor secretion by ciliary epithelium
____ decrease IOP by increasing outflow of aqueous humor
NS-Beta blocker (timolol)
CAI (acetazolomide)
PGF2alpha (latanoprost, travoprost) or Cholinomimetics (pilocarpine, carbachol)
What molecule binds GP1b?
Deficiency in the above molecule results in what change in blood tests?
Function of ristocetin
vWF binds GP1b.
Abnormal ristocetin and decrease F8, so increased PTT.
Ristocetin activates vWF to bind GP1b.
How is Bernard-Soulier different from vWF deficiency?
Bernard is hereditary deficit in GP1b receptors.
vWF is a deficiency.
Ristocetin will be abnormal for both, but when normal plasma is added, vWF will have a normal ristocetin test while Bernard will not.
What is GP2b-3a deficiency? What is ristocetin test - abn or normal?
Glanzmann thrombasthenia. Normal ristocetin
thrombocytopenia, enlarged platelets, mucocutaneous bleeding
Bernard-Soulier
What is mosaisism, Robertsonian (unbalanced) translocation, and _____ = ___?
meiotic nondisjunction = 3 causes of Down Syndrome
meiotic nondisjunction can also cause Kleinfelter
Alk phos measures what cell in bone remodeling?
osteoblast - it is released as bone matrix is synthesized
also released from liver, placenta, and intestine. bone alk phos is denatured by heat
TRAP, urinary hydroxyproline, and urinary deoxypyridinoline measure acitivity of what cell in bone remodeling?
osteoclast
give what substance to promote apoptosis/menstrual bleeding?
medroxyprogesterone
What is a drug used for peripheral artery disease that arterial vasodilates and decreases platelet aggregation?
cilastazol - a PDE inhibitor
What IL-__ has ANTI inflammatory properities?
IL-10 (reduces Th1, MHC2, macrophages, and DC)
MC pathogens that infect sickle cell patients
HiB and Strep pneumo
Why is there pretibila myxedema in gRaves disease (hyper thyroid)
bc autoimmune response to TSH receptors causes buildup of glycosaminoglycans
foot slap - nerve. cannot evert food, cannot feel sensation on dorsum or lateral shin
common fibular
Causes pneumonia, brain abcesses, and cutaneous involvement in esp immunocompromised. Gram positive, catalase positive, Acid fast
Nocardia
mucosal neuromas with marfanoid habitus
MEN 2B (pheo, mucosal neuromas, marfanoid habitus, medullary thryoid.
Pancreatic tumor (esp gastrinoma), Pituitary (prolactinoma and visual defects), and Primary hyperparathyroid (hypercalcemia)
MEN1
Medullary thyroid carcinoma (calcitonin), pheochromocytoma, parathyroid hyperplasia
MEN2A
three Bacteria that use transformation - the direct uptake of naked DNA
Strep pneumo, Haemophilus, N gono/meningitidis
S3 is best heard in left lateral decibitus position at _____ time. Abn in adults - indicates ___
ventricular enlargement, best heard at the end of exhalation
Cardiac tamponade, COPD, severe asthma, and constrictive pericarditis all have what in common?
pulsus paradoxus (systolic >10mmHg different upon inspiration v expiration
Arterial supply to ureters:
proximally is renal artery
distally is superior vesicle artery
in between in variable and anastomotic
testosterone secreting ovarian tumor
sertoli-leydig
What does mitochondrial vacuolization signify?
irreversible cellular damage
“bilateral hilar LAD”
sarcodiosis
what drug inhibits platelet aggregation by irreversibly blocking ADP receptors, which dows not allow for GP2b3a expression, thus inhibiting fibrinogen binding.
clopidogrel
