This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Chemotherapy: General Principles, Subject name: Pharmacology
[{'content': 'Which of the following beta-lactam antibiotics can be safely used in a patient with a history of allergy to penicillins? \nSelect and explain. \nA. Aztreonam, B. Cefepime, C. Loracarbef, D. Ceftriaxone', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Ans. (A) Aztreonam(Ref: KDT 8/e p781)Aztreonam is the only beta lactam antibiotic that can be used in patients having severe allergy to penicillins or cephalosporins (as it is not cross allergenic).', 'role': 'assistant'}]