USMLE-Rx Review Flashcards
What side-effects are associated with Digoxin?
What is its MOA?
What is the biggest concern when this drug becomes toxic?
Nausea, dizziness and blurry vision with a yellowish hue. There is a very narrow therapeutic index.
Inhibition of the Na+/K+ pump, which leads to increased intracellular [Na+] and increased extracellular [K+]. The increased [Na+] inhibits the Na+/Ca++ pump, which increases intracellular [Ca++]. This increases contractility.
The induced hyperkalemia can cause fatal arrhythmias.
What is Phenoxybenzamine used for?
What is its MOA?
First-line therapy of in a patient with a Pheochromocytoma. Without adequate alpha-receptor blockade, patients are at a risk for intraoperative hypertensive crisis.
Irreversible antagonism of a-1 and a-2 receptors.
In terms of treating a Pheochromocytoma, when should Propanolol be given? Why?
What is its MOA?
It should be given after administration of an alpha-receptor antagonist. This must be done secondly, because if it is done first, it can result in a further spike in BP due to blockade of the beta2-receptor-mediated vasodilation.
Non-selectively blocks beta-receptors.
What is the MOA of Labetalol?
It blocks both alpha and beta receptors.
What is the MOA of Octreotide?
What is its indication?
It is a synthetic analog of somatostatin.
Used to manage symptoms of carcinoid tumors.
What is the confidence interval?
What is the variance?
What is the standard deviation?
Confidence interval: a range of values where the mean is expected to fall.
Variance: helps describe the variability within a population, but does not draw any conclusions regarding the range within the mean can be found.
Standard deviation: shows the variability existing among a range values typically centered around the mean.
What is the MOA of Lidocaine?
When should it be given?
It is a class-1B anti-arrhythmic and blocks inactivated Na+ channels.
It is used to treat ventricular arrhythmias after an MI.
What causes an SVT?
What are the 2 general mechanisms by which they arise?
Either the atria or AV node causes an abnormally fast HR.
Increased automaticity - AV node re-entry tachycardia (AVNRT).
Re-entry - AV re-entry tachycardia (AVRT).
In addition to conservative measures (carotid massage, etc.), what is the first-line pharmacological therapy used to treat SVTs?
How does it cause effects?
What are side-effects?
IV adenosine.
It has a short half-life and acts by slowing the conduction velocity and increasing the refractory period at the AV node.
Flushing, hypotension and chest pain.
What are the indications for the following:
Amiodarone
Amlodipine
Procainamide
Amiodarone: VT and Afib.
Amlodipine: to reduce SVR and arterial pressure. It is a CCB and does not effect the myocardium.
Procainamide: atrial and ventricular arrhythmias.
What is the classic sign of an SVT on an ECG?
Narrowed QRS complexes
What are the treatment options for Digoxin toxicity?
Normalization of electrolytes
Lidocaine
Digoxin immune Fab
Mg++
Which types of diuretics may cause hypercalcemia?
Thiazide diuretics
Which bacteria is associated with Guillan-Barre syndrome?
C. jejuni
What kind of bug is C. jejuni?
How is it transmitted?
What are symptoms of an infection?
What is the progression of the infection?
G- motile rod.
Consumption of unpasteurized milk, untreated water or under-cooked poultry. It is also a zoonotic that can be transmitted by animals (dogs, cats, pigs, etc.)
Bloody diarrhea, abdominal pain, fever, emesis.
Typically is self-limiting.
What food is B. cereus associated with?
Reheated rice
What is a case-control study?
What are they used for?
Compares people with a disease to a gruop of people without the disease to determine the odds of prior exposure or risk factors.
They are cheap and are used in a preliminary fashion, due to the fact that they are observational in nature and are low in the hierarchy of evidence.
What is a randomized control study?
What are the advantages and disadvantages of this study?
A study where one group gets a medicine and the other gets a placebo, and neither the patients nor the researchers know which is which.
Advantages: most reliable form of scientific evidence, as they reduce spurious causality and bias.
Disadvantages: expensive, requires a lot of time, conflicts of interest and ethical concerns.
What is a cohort study?
They compare a group with a given exposure or risk factor to a group without it.
What is a case-series?
A type of clinical research study where subjects with known exposure are tracked and their outcomes are measured and compared.
What is an open-label trial?
A study where participants and researchers are aware of the study arm in which participants are allocated. There is no blinding or masking of participants or researchers.
Which IBD is associated with acute cholecystitis?
Crohn disease
What is a classic feature of Crohn disease?
What part of the GI does it usually affect? What is the consequence of this?
Transmural skip lesions, which may lead to strictures.
Terminal ileum. This leads to decreased bile acid reabsorption, which causes formation of cholesterol stones (acute cholecystitis).
What kind of stones are caused by hemolysis of RBCs?
Pigment stones, which can obstruct the Gb.
What is a gallstone ileus?
A passage between the SI and the Gb that a gallstone can enter and cause obstruction in the SI. This would present with symptoms similar to a SBO.
What are the symptoms of ascending cholangitis?
Fever, jaundice and abdominal pain, which may progress to shock, altered mental status and/or death.
What are the major side-effects of calcium carbonate?
Hypercalemia - fatigue, muscle weakness, depression and constipation.
Hypokalemia
Hypophosphatemia
*Milk-alkali syndrome
What is electrolyte abnormality is associated with magnesium hydroxide?
Hypokalemia
What is the major side-effect of aluminum hydroxide?
What are electrolyte abnormalities?
Constipation
Hypokalemia and hypophosphatemia
What is the effect of Digoxin on EF and HR?
Increased EF, increases HR due to increased vagal tone (because of inhibition of AV node).
What is the major side-effect of Metformin?
What is its MOA?
What are its main effects?
Lactic acidosis (usually only in patients w/ concomitant RF): SOB, abdominal pain, altered mental status, hypotension, and HAGMA in the setting of RF.
Inhibits hepatic mitochondrial enzymes which inhibit gluconeogenesis.
Increases glucose sensitivity in peripheral tissues and increases peripheral glucose utilization.
What are features of Pompe disease?
What is the cause of death in infants with this disease?
What kind of disease is it?
What is a classic histological finding?
Glycogen buildup in the liver, heart and skeletal muscle which lead to cardiomegaly.
Weakness/hypotonia.
Cardiorespiratory failure.
Lysosomal a-glucosidase deficiency. It is a type 2 glycogen storage disease.
PAS-positive (glycogen within lysosomes).
Which enzyme deficiencies and symptoms are associated withe the following glycogen storage diseases:
Cori disease
Von Gierke
Galactose-1-phosphate uridyltransferase deficiency
McArdle disease:
Cori disease: a-1,6-glucosidase deficiency; hypoglycemia.
Von Gierke: glucose-6-phosphatase; severe hypoglycemia (> Cori disease).
Galactose-1-phosphate uridyltransferase deficiency; infantile cataracts.
McArdle disease: myoglycogen phosphorylase deficiency; MSK symptoms (myalgias, etc.).
What is the MOA of adenosine?
Binds to A1 receptors in cardiac cells and leads to K+ channel activation and inhibition of L-type Ca++ channels, which causes a conduction delay through the AV node (reason it is given for arrhythmias).
What the effect of using a PDE3 inhibitor?
What is the MOA?
What are some examples?
Increased cardiac contractility and decreased PVR.
Inhibits the breakdown of cAMP in myocardial and smooth muscle cells.
Milrinone, anagrelide, cilostazol.
What is the effect of Carvedilol on cardiac contractility and PVR?
It decreases contractility and PVR.
What are symptoms of PAN?
What is the pathophysiology?
Which antibodies are negative?
What kind of hypersensitivity is it?
Hep. B, fever, weight loss, abdominal pain, melena, HTN, renal damage.
Immune-complex mediated vasculitis of medium-sized arteries (renal aa., etc.).
ANCA-negative
Type III hypersensitivity.
What are the ANCA+ vasculitities?
Microscopic polyangiitis
Granulomatosis with polyangiitis (Wegener’s)
Eosinophilic granulomatosis with polyangiitis (Churg-Strauss syndrome)
What becomes oxidized in tissues with iron overload?
Tyrosine in melanocytes
What is a Mallory-Weiss tear?
A longitudinal laceration of the mucosa at the GEJ. Painful hematemesis follows prolonged episodes of vomiting and retching, and generally resolves spontaneously. Less severe than Boerhaave’s syndrome.
What comes from the 1st pharyngeal arch?
What comes from the 2nd pharyngeal arch?
What comes from the 3rd pharyngeal arch?
What comes from the 4th pharyngeal arch?
What comes from the 5th pharyngeal arch?
What comes from the 6th pharyngeal arch?
1st - muscles of mastication.
2nd - numerous facial muscles.
3rd - stylopharyngeus m. and hyoid.
4th - most of the pharynx.
5th - rudimentary; no structures.
6th - arytenoid cartilages and intrinsic muscles of larynx. Fuses with the 4th PA.
What occurs in laryngomalacia?
It occurs due to a defect of which PA?
Bulky arytenoid cartilages prolapse anteromedially on inspiration, resulting in stridor.
PA 6.
Which malignancy is associated with SIADH?
Small cell lung carcinoma
Do “cold” or “hot” thyroid nodules sugest excessive TH from an overactive thyroid?
Cold nodules
What causes thyrotoxicosis factitia?
What are the TSH, T3 and T4 levels?
What is the outcome of the radioactive iodine uptake (RAIU) test?
Ingestion of exogenous levothyroxine, usually in an effort to lose weight (not realizing the adverse effects).
Low TSH; high T3/4.
Little to no uptake on RAIU test.
What kind of drug is Verapamil?
A CCB that blocks phase 0 (VG Ca++ channels) decreasing conduction through the AV nodes.
What is the MOA of Atropine?
Muscarinic antagonist that increases HR, but has no inotropic effects on the heart.
What is the MOA of NIfedipine?
DHP Ca++ channel blocker which causes signififcant vasodilation, with little effect on pacemaker APs.
What is the MOA of Procainamide?
Blocks Na+ and K+ channels
What is the MOA of Gemfibrozil?
What is a common side-effect?
It is a fibrate and acts on PPAR-a to increase TG clearance.
Gallstone formation, due to reduced cholesterol solubility via inhibition of 7a-hydroxylase.
What are side-effects of Statins?
Hepatotoxicity and myopathy
What are side-effects of Exetimibe?
Hepatotoxicity or diarrhea.
What metabolic changes occur after Niacin use?
What are some side-effects?
Increased HDL and decreased LDL and TGs.
Flushing, hyperglycemia and hyperuricemia.
What kind of virus is Coxsackie B?
What ECG findings might be associated with an infection?
Single-stranded, naked. icosahedral RNA virus
ST-elevation and PR segment depression (Myocarditis)
Which nodes are common to be seen in gastric cancer?
Periumbilical node (Sister Mary Jospeh node) and supraclavicular lymphadenopathy (Virchow’s node)
PDE-5 inhibitors are contraindicated in which patients?
What’s the MOA?
Patients who take nitrates for chest pain.
Inactivation of second messengers, like cGMP.
Where is iron absorbed?
Duodenum