ATI RN
Quizlet ATI Pharmacology Final Questions
Question 1 of 5
Drug X has a median lethal dose of 30 mg and a median effective dose of 10. Drug Y has a therapeutic index of 4, while drug Z has a therapeutic index of 3. Which statement is accurate based on this information?
Correct Answer: C
Rationale: Therapeutic index (TI) = lethal dose (LD50) / effective dose (ED50). Drug X: 30/10 = 3. Drug Y: TI = 4. Drug Z: TI = 3. Higher TI means safer-Drug Y (4) tops X and Z (3), balancing efficacy and toxicity best. X and Y aren't both safer-X matches Z. X's TI isn't 20. Z isn't safest. Y's TI makes it safest.
Question 2 of 5
The following drugs must be avoided in severe renal failure (GFR ≤10 mL/min):
Correct Answer: D
Rationale: Metformin is contraindicated in severe renal failure due to the risk of lactic acidosis, a rare but potentially fatal side effect.
Question 3 of 5
A 24-year-old woman medical student with a history of depression presents to the emergency department with tachycardia and shallow breathing. After her initial presentation, she begins to become confused and has a seizure. An ECG is performed and shows QT prolongation. An arterial blood gas shows metabolic acidosis. She has been taking antidepressants for a couple of years, but her depression is worsening. She had a test yesterday and told her mother that she felt she did poorly. There is concern that she has overdosed on her medication. What is the most appropriate treatment?
Correct Answer: D
Rationale: TCA overdose (QT prolongation, seizures, acidosis) requires sodium bicarbonate . It corrects acidosis and stabilizes cardiac membranes. Ammonium chloride worsens acidosis. Atropine and Flumazenil are irrelevant. N-acetylcysteine (E) is for acetaminophen. Bicarbonate addresses her acute toxicity.
Question 4 of 5
A 42-year-old female who is obese and with a history of gallstones and cholecystitis complains of superficial skin swelling and itching. Physical examination by the primary care physician reveals skin erythema, tenderness, and swelling consistent with cellulitis. The patient is given a prescription for erythromycin. Which of the following effects must the treating physician be keenly aware of?
Correct Answer: A
Rationale: Erythromycin for cellulitis risks cholestatic jaundice , especially in patients with gallstone history. Abdominal discomfort , nausea , and vomiting (E) are common but less severe. Tinnitus is rare. Jaundice, from hepatic dysfunction, requires monitoring given her biliary background.
Question 5 of 5
A client who is receiving edrophonium chloride suddenly is complaining of abdominal cramps and the nurse observes the client is experiencing increased perspiration and salivation. The nurse makes sure the availability of which of the following?
Correct Answer: C
Rationale: The symptoms of abdominal cramps, increased perspiration, and salivation suggest cholinergic excess, which can occur with edrophonium chloride. Atropine sulfate is the antidote for cholinergic toxicity and should be readily available to counteract these effects. Levodopa, methylphenidate, and carbamazepine are not used to treat cholinergic excess. Therefore, atropine is the correct medication to have on hand.