This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Pharmacology
Ciprofloxacin should not be used with theophylline because- 
Select and explain. 
A. it decreases efficiency of theophylline, B. it increases toxicity of theophylline, C. it decreases efficiency of ciprofloxacin, D. it decreases absorption of theophylline
B: it increases toxicity of theophylline
Answer: B: it increases toxicity of theophylline 
Explanation: Ans. is 'b' i.e., It increases the toxicity of theophylline Impoant interactions of FOs o Plasma concentration of theophylline, caffine and warfarin are increased by ciprofloxacin, norfloxacin and pefloxacin. o NSAIDSs enhance CNS toxicity of FQS. o Antacids, sucralfate and iron salts reduce absorption of FQs.