A 70-year-old woman is admitted to the hospital with a fractured hip after a fall.
Laboratory results are as follows:

Which of the following medications is most likely responsible for her acid-base abnormality?

Question

A 70-year-old woman is admitted to the hospital with a fractured hip after a fall.
Laboratory results are as follows:

Which of the following medications is most likely responsible for her acid-base abnormality?

Quizplus · Accepted Answer

11ec193a_9723_dc5d_853d_830d04791267_MD0002_00 This patient presents with non-anion gap metabolic acidosis, which can be caused by numerous agents. Carbonic anhydrase inhibitors, including acetazolamide (used for glaucoma) and topiramate (used for seizures and migraine headaches), typically cause bicarbonate diuresis with resultant non-anion gap metabolic acidosis. Many of the other implicated agents cause mild forms of renal tubular acidosis with accompanying non-anion gap metabolic acidosis, sometimes due to interstitial nephritis. (Choices B and D) Neither of these agents have been known to cause renal tubular acidosis or non-anion gap metabolic acidosis. (Choice C) Metformin has been associated with lactic acidosis that causes an anion gap metabolic acidosis. (Choice E) Zoledronic acid has rarely been associated with acute kidney injury, but causes neither renal tubular acidosis nor non-anion gap metabolic acidosis. Educational objective: Several pharmacologic agents are associated with non-anion gap metabolic acidosis. Acetazolamide inhibits carbonic anhydrase and typically causes bicarbonate diuresis with a non-anion gap metabolic acidosis. __________ References: Acetazolamide and symptomatic metabolic acidosis in mild renal failure. (http://www.ncbi.nlm.nih.gov/pubmed/6799050) Effect of topiramate on acid-base balance: extent, mechanism and effects. (http://www.ncbi.nlm.nih.gov/pubmed/19916989)

A 70-Year-Old Woman Is Admitted to the Hospital with a Fractured