USMLE1 Practice Questions-4

1. A 45 year old female presents to your office with complaints of a 3 month history of aches and pains in her hands. She says that both of her hands are equally affected, but the pain is limited to only some of her joints. Upon further questioning, you find that the joints that are affected are the MCP's and PIP's. The patient also says that she has morning stiffness for about 45 minutes but gets better when she starts doing her morning chores. A potential treatment for this patient's condition can also be used in the treatment of an infectious disease that causes hemolytic anemia. Which of the following is the correct mechanism of action of this drug?
A. Binds to an inflammatory cytokine
B. Inhibits chemotaxis of inflammatory cells
C. Inhibits an enzyme involved in DNA synthesis
D. Inhibits an enzyme involved in prostaglandin synthesis
E. Is structurally similar to a cell surface receptor

2. A 67 year old male patient presents to your office with his wife. She is very concerned because she says that her husband has become progressively inactive over the past couple years. He sits on the couch with a blank look on his face and his hands shake when he is not using them. She says that her husband used to be very happy, but now he barely even smiles. You examine the patient and notice that he has a shuffling gait. One of the potential drugs used in the treatment of this patient is also an anti-viral medication that works by which of the following mechanisms?
A. Inhibits DNA-dependent RNA polymerase
B. Blocks attachement/release of virus
C. Inhibits uncoating of the virus
D. Inhibits mRNA transcription
E. Inhibits DNA-dependent DNA polymerase
F. Inhibits Reverse Transcriptase

3. A 6 year old male patient presents to the emergency room with his mother with severe vomiting, excessive salivation, urinary and bowel incontinence, and miosis. The mother is frantic and says that her son had gotten into one of their medicine cabinets and ingested some bug spray less than 2 hours ago. A drug that you administer to treat this condition acts in which of the following ways?
A. Binds to and inhibits an enzyme
B. Cleaves an effector molecule
C. Phosphorylates an effector molecule
D. Irreversibly binds to a receptor
E. Decreases the Vmax of an enzyme

4. Milrinone is a strong inotropic agent. Its mechanism of action involves inhibition of phosphodiesterase isoenzyme 3. Which of the following additional responses is most likely an extension of its pharmacologic effect?
A. Angioedema
B. Antiarrhythmic action
C. Vasodilation
D. Increased right atrial pressure
E. Sodium and water retention
F. AV conduction block

5. A 42 year old man is brought into the emergency dept. with diffuse muscle weakness & heart palpitations. Physical examination reveals tachycardia, mydriasis and an elevated body temperature. Which of the following would most likely lead to all of this patients symptoms?

A. Atropine

B. Ephedrine

C. Phenelzine

D. Botulinum Toxin

E. Succinylcholine

6. If a drug is highly bound to plasma proteins, it:
A. has a large Vd.
B. has a high renal clearance.
C. is a likely candidate for drug interactions.
D. is most likely carried by alpha-glycoprotein.
E. is a quaternary ammonium salt.
7. most drugs gain entry to cells by:
A. passive diffusion with zero-order kinetics.
B. passive diffusion with first-order kinetics.
C. active transport with zero-order kinetics.
D. active transport with first-order kinetics.
E. passive diffusion through membrane pores.

8. A patient known to be a heroin abuser comes to ER with a painful stab wound . The ER physician administers Nalbuphine for the pain. Why is this not a good idea?
a. The patient is probably tolerant to Nalbuphine.
b. The drug may precipitate a withdrawal state.
c. Nalbuphine is a weaker analgesic than codeine .
d. Vasodilating effects of nalbuphine increase blood loss .
e. Nalbuphine is a strong miu receptor agonist .

9. A 54 yr old man is hospitalized after a planned abdominal surgery. One of his physicians administers a new drug whose mechanism of action you do not know. Shortly after administration, the pt develops flushing, daiphoresis & nausea. His blood pressure is 100/70 mm Hg & heart rate is 55/ min. His pupils are constricted but reactive to light. The medication is most likely given for which of the following conditions?

A. Fluid overload

B. UTI

C. Urinary obstruction

D. Hypovolemic shock

E. Atonic Bladder

10. A pharmaceutical company has developed a drug that prevents egress of Mg+2 from N-methyl D aspartame (NMDA) receptor. What is most likely effects of this drug in a patient with acute stroke?
A) Decreased risk of seizures because of hypomagnesima
B) Facilitation of Ca entry into neuron and enhancement of excitation mediated cell death
C) Hyperpolarization of membrane and conduction block
D) Prevention of Ca+2 entry into neuron and reduction of excitation mediated cell death
E) Rapid depolarization of membrane with lowering of seizure threshold

Answers: 1.B, 2. C, 3. B, 4. C, 5. D, 6. C, 7. B, 8. B, 9. E, 10. D