STEP 1 Uworld Drugs Part 3

Question 1

Nystatin

Answer 1

= polyenes = bind ergosterol in fungal cell membranes creating pores and causing cell lysis

Question 2

Entacapone

Answer 2

COMT inhibitor that increases the bioavailabilty of levodopa by inhibiting its peripheral methylation

Question 3

Rituximab

Answer 3

monoclonal antibody that targets the CD20 surface immunoglobulin, used in lymphoma immunotherapy

Question 4

Nevirapine

Answer 4

NNRTI (non-nucleotide reverse transcriptase inhibitor)

Question 5

Ezetimibe

Answer 5

Decreases intestinal absorption of cholesterol by inhibiting the Nieman-pick Cl-like (NPC1L1) transport protein.

Amount of cholesterol reaching the liver decreases –> to compensate, the liver increases LDL receptor expression which draws cholesterol out of the circulation.

Question 6

Rasburicase

Answer 6

recombinant version of urate oxidase

It catalyzes conversion of uric acid to allontoin, a more soluble metabolite.

Question 7

Enoxaparin

Answer 7

LMWH that has less anti-thrombotic activity compared to unfractionated heparin (fewer saccharide units that bind thrombin)

Question 8

Ramelteon

Answer 8

melatonin agonist to melatonin receptors in suprachiasmatic nucleus

Question 9

Dihydroergotamine

Answer 9

Ergot alkaloid used to treat migrane headaches. Stimulates both alpha-adrenergic (partial agonist) and serotonergic receptors (constricts vascular smooth muscle)

Question 10

Doxazosin

Answer 10

an a1-blocker useful in treatment of both benign prostatic hyperplasia and hypertension

Question 11

Dobutamine

Answer 11

B-adrenergic agonist with predominant B1 activity –> increase in heart rate and contractility with mild vasodilation –> increased myocardial oxygen consumption

Question 12

Ethosuximide

Answer 12

Blocks T-type Ca2+ channels in the thalamic neurons. Tx: for absence seizures

Question 13

Atenolol

Answer 13

selective B1 blocker (B1 are found on cardiac tissue and renal juxtaglomerular cells)

Question 14

Cholestyramine

Answer 14

bile acid binding resin. Binds bile acids in the intestinal tract –> increased bile excretion –> increases hepatic cholesterol and bile synthesis (often used synergistically with a statin)

Question 15

fibrates (fenofibrate, gemfibrozil)

Answer 15

inhibit 7a-hydroxylase, which catalyzes the rate limiting step of bile acid synthesis –> decreases cholesterol solubility in bile (risk of cholesterol gallstones)

Question 16

Clopidogrel

Answer 16

irreversibly blocks P2Y12 component of ADP preceptors on platelet aggregation (as effective as aspirin in prevention of cardiac events - use in aspirin allergy)

Question 17

Daptomycin

Answer 17

lipoprotein antibiotic that causes depolarization of bacterial cell membrane and inhibition of DNA, RNA, and protein synthesis..

activity agianst G(+) and MRSA (inactivated by pulmonary surfactant)

Question 18

Raloxifene

Answer 18

SERM –> in bone, estrogen agonist effects prevent osteoporosis. In mammary and uterine tissue, the estrogen antagonist effects prevent breast cancer and endometrial cancer.

Question 19

Penylephrine

Answer 19

Selective a1 adrenergic receptor agonist that increases peripheral vascular resistance and systolic blood pressure and decreases pulse pressure and heart rate

Question 20

Cyclosporin

Answer 20

Immunosuppressant that binds cyclophilin

The cyclosporin-cyclophilin complex inhibits the enzyme calcineurin.

Calcinurin is responsible for active transcription factors for IL-2 production which halts growth and differentiation of T-cells

Question 21

Cabergoline

Answer 21

Dopamine agonist (these are first line treatment for prolactinoma)

Question 22

Lopinavir

Answer 22

protease inhibitor (-navir) –> reversibly inhibit viral protease, an enzyme responsible for HIV poly protein cleavage to form mature viral proteins

Question 23

Latanoprost

Answer 23

topical prostaglandin –> increase outflow of aqueous via the uvescleral pathway and are the preferred treatment for open-angle glaucoma

Question 24

Busprione

Answer 24

nonbenzodiazepine anxiolytic –> partial agonist of 5HT1A receptor, slow onset of action, lacks muscle relaxant or anticonvulsant properties, No risk of dependence. Tx of general anxiety disorder.

Question 25

Dimercaprol

Answer 25

chelating agent --> increases urinary excretion of heavy metals by forming stable, nontoxic soluble chelates, used for arsenic poisoning

Question 26

Capsaicin

Answer 26

topical pain reliever that causes defunctionalization of afferent pain fibers and depletion of substance P

Question 27

Buprenophine

Answer 27

partial opioid agonist that has low intrinsic activity (efficacy) for opioid mu-receptors but binds with high affinity (potency) and can prevent binding of other opioid medications (can cause withdraw in pts on long-term opioid therapy)

Question 28

Fenoldopam

Answer 28

Short-acting, selective, peripheral dopamine-1 receptor agonist --> activates adenylyl cyclase --> vasodilation --> decreases BP (renal vasodilation is particularly prominent and leads to increased renal perfusion, diuresis, and natriuresis) [used for hypertensive emergency]

Question 29

Milrinone

Answer 29

Phosphodiesterase (PDE)-3 inhibitor --> Increases cAMP --> myocardial contractile and systemic arterial and venous dilation

Question 30

Phenelzine

Answer 30

a monoamine oxidase inhibitor that works by irreversibly binding and inhibiting MAO-A and B; (if switching to SSRI, need about 2 wks to regeneration MAO and avoid serotonin syndrome