Pharmacology All of the following are true regarding penicillin except: March 2005 A Probenecid decreases it duration of action B All penicillin are active against gram positive organisms C Splits into 6-amino penicillanic acid by amidase D Acts by inhibiting cell wall synthesis 💡 Explanation All of the following are true regarding penicillin except: March 2005 ✓ Correct Answer: A. Probenecid decreases it duration of action