Pharmacology Dosage of benzyl penicillin in treatment of primary syphilis is : A 1.2 MU single i.m. B 1.2 MU single i.v. C 2.4 MU single i.m. D 4.8 MU single i.m. 💡 Explanation Dosage of benzyl penicillin in treatment of primary syphilis is : ✓ Correct Answer: C. 2.4 MU single i.m.