The client with GERD is taking cimetidine. Which serum laboratory finding should the nurse determine is most concerning?

A: Elevation of liver enzymes should be most concerning because drug-induced hepatitis is an adverse effect of cimetidine (Tagamet HB) therapy. B: Histamine-2 receptor blockers can cause myelosuppression including thrombocytopenia. A decreased (not increased) platelet count would be concerning. C: Renal adverse effects of the drug include elevated (not decreased) creatinine and BUN. D: Cimetidine can increase (not decrease) secretion of prolactin from the anterior pituitary, inducing gynecomastia.