This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Other topics and Adverse effects, Subject name: Pharmacology
Which one of the following statements about doxycycline is FALSE? 
Select and explain. 
A. It is bacteriostatic, B. It is excreted mainly in the feces, C. It is more active than tetracycline against H.pylori, D. It is used in Lyme's disease
C: It is more active than tetracycline against H.pylori
Answer: C: It is more active than tetracycline against H.pylori 
Explanation: (Ref: KDT 6/e p637, 710, 712, 713) Doxycycline is a bacteriostatic agent that acts by inhibiting protein synthesis. It is safe in renal failure as it is excreted mainly in feces. Doxycycline is useful in Lyme's disease. Tetracycline (and not doxycycline) is useful in H.pylori therapy.