This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Cell Wall Synthesis Inhibitors, Subject name: Pharmacology
[{'content': 'Which of the following statements about the biodisposition of penicillins and cephalosporins is NOT accurate? \nSelect and explain. \nA. Oral bioavailability is affected by lability to gastric acid, B. Procaine penicillin G is used intramuscular injection, C. Renal tubular reabsorption of beta-lactams is inhibited by probenecid, D. Nafcillin and ceftriaxone are eliminated mainly biliary secretion', 'role': 'user'}, {'content': 'Answer: C \nExplanation: * Probenecid inhibits renal tubular secretion of penicillins (not reabsorption) * Beta lactams eliminated by biliary route are: -- Ampicillin -- Nafcillin -- Ceftriaxone -- Cefoperazone * Penicillin G has to be given by i.m. route because it is broken down by gastric acid (decreases oral bioavailability).', 'role': 'assistant'}]