For a patient with chronic kidney disease and worsening serum creatinine, which course of action is recommended?

In managing a patient with chronic kidney disease (CKD) experiencing worsening serum creatinine, the recommendation to discontinue hydrochlorothiazide is supported by the specific pharmacodynamics of thiazide diuretics and their efficacy relative to renal function. Hydrochlorothiazide is primarily effective when renal function is adequate, as its diuretic effect diminishes significantly when the glomerular filtration rate (GFR) is lower than 30 mL/min. In such cases, the risks of continued use may outweigh potential benefits, especially as worsening kidney function can lead to electrolyte imbalances, dehydration, or further renal impairment.

In contrast, the other options involve medications that either do not warrant discontinuation in the setting of worsening renal function or may pose potential risks if dosed without addressing the changes in renal clearance adequately. Increasing the dose of amlodipine or lisinopril in the context of declining renal function should be approached with caution and is typically not the first-line response without further evaluation of the patient’s overall clinical status and renal function. Therefore, the safest and most appropriate recommendation in this scenario is to discontinue hydrochlorothiazide given its limited efficacy and potential for adverse effects in the setting of CKD and worsening kidney function.