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
A nursing mother presented with fever and breast tenderness after two weeks postpaum. Which oral antibiotics is ideal for her condition? 
Select and explain. 
A. Ampicillin, B. Dicloxacillin, C. Ceftazidime, D. Ciprofloxacin
B: Dicloxacillin
Answer: B: Dicloxacillin 
Explanation: Dicloxacillin:- Anti - staphylococcal penicillin :- B lactamase resistant penicillin. Their use is restricted to the treatment of infection cause by penicillinase producing staphylococci including MSSA. Other drug of this class:- Methicillin Oxacillin Methicillin because of its toxicity (interstitial Nephritis), Methicillin is not used. Ampicillin/Amoxicillin:-Extended- Spectrum penicillin. More effective against gram -ve bacilli. Ampicillin is a drug of choice for gram positive bacilli : listeria monocytogenes Ceftazidime:-3rd gen cephalosporin, has activity against P. aeruginosa Ciprofloxacin: of the fluoroquinolone it has best activity against P. Aeruginosa and is commonly used in cystic fibrosis patient.