This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Chemotherapy, Subject name: Pharmacology
Which of the following beta lactam antibiotic can be safely used in a patient with a history of allergy to Pencillin 
Select and explain. 
A. Aztreonan, B. Cefepime, C. Loracarbef, D. Ceftriaxone
A: Aztreonan
Answer: A: Aztreonan 
Explanation: Refer KDT 6/e p708 Aztreonan is the only beta lactam anti6 that can be used in patients having severe allergy to Pencillin or cephalosporin