usmle questions

A 54 year-old man with a history of chronic obstructive pulmonary disease (COPD) presents by his son to the emergency room semi-unconscious with shortness of breath. He has nausea, diarrhea and restlessness for the last four hours.  His arterial oxygen saturation is 88% with room air. His ECG shows normal sinus rhythm with non-specific changes … Read more

A 33-year-old woman presents to the clinic for her regular yearly physical examination. She has a long history of depression and takes fluoxetine regularly for two years. Which amino acid is the precursor of the neurotransmitter affected by this drug? A- Glycine B- Glutamate C- Methionine D- Phenylalanine E- Tryptophan Answer Fluoxetine is a selective … Read more

A 45 year-old man presents with progressive burning epigastric pain. He smokes and drinks alcohol socially. Physical examination, laboratory tests and imaging studies confirm the diagnosis of peptic ulcer. He is prescribed omeprazole. What is the effect of this medication that improves this condition? A-Anti-cholinergic effect B-Inhibition of H+/K+ ATPase pump C-Blocking of H2 receptor … Read more

A 29-year-old woman with a history of rheumatic heart disease and prosthetic aortic valve presents to her physician for consultation. She is referred by her dentist for prophylaxis before she undergoes an oral surgery next month. She has no history of bacterial endocarditis. She is allergic to penicillin. Which of the following is the prophylactic … Read more