A 43-year-old man with a history of peptic ulcer disease has developed hypersensitivity to H₂ blockers. He now complains of worsening of his dyspepsia. Physical examination reveals mild tenderness on the midepigastric region. If misoprostol is prescribed to this patient, which of the following mechanisms of action would be most plausible for this agent?

A 43-year-old man with a history of peptic ulcer disease has developed hypersensitivity to H₂ blockers. He now complains of worsening of his dyspepsia. Physical examination reveals mild tenderness on the midepigastric region. If misoprostol is prescribed to this patient, which of the following mechanisms of action would be most plausible for this agent?

A 19-year-old male presents to the emergency room with a broken ankle after a fall. He is given hydrocodone for the pain and, soon after, his stomach becomes upset. He has vomited once. The patient is given ondansetron to treat his nausea. What is the mechanism of action of ondansetron?

A 65-year-old man with long-standing schizophrenia has been taking an antipsychotic agent since his diagnosis of schizophrenia at age 19 years. He has been in and out of psychiatric hospitals for most of his adult life. Long-term adverse effects of these agents may include which of the following?

A 62-year-old man presents to his primary care physician for follow-up. He has a history of an atrial arrhythmia. He takes multiple medications but does not know the names of them. He now complains of headache, dizziness, and tinnitus. Which one of the following antiarrhythmic drugs is the most likely cause?

A 39-year-old woman with chronic migraine headaches manages her condition with ibuprofen 200 mg. Most days, she does well with 200 to 400 mg. Adverse reactions to this therapy include which of the following?