Which treatment for dyspepsia could potentially decrease the renal excretion of memantine and cause toxicity?

A. Lansoprazole is a proton pump inhibitor (PPI) used to reduce gastric acid secretion. It does not significantly affect the renal excretion of memantine and is not associated with increased toxicity of this drug. B. Ranitidine is an H2-receptor antagonist that decreases stomach acid. Like PPIs, it does not impact renal clearance of memantine and is generally safe to use concurrently. C. Calcium carbonate is an antacid that can affect gastric pH and absorption of some medications but does not significantly alter the renal excretion of memantine. It is not associated with memantine toxicity through renal mechanisms. D. Sodium bicarbonate is an alkalinizing agent that increases urinary pH. Memantine is excreted primarily by the kidneys, and its renal clearance is pH-dependent. Alkalinization of the urine can reduce the renal excretion of memantine, leading to drug accumulation and potential toxicity, including confusion, agitation, dizziness, and hypertension.