What is the generic name of Vibramycin?

Vibramycin is the brand name for doxycycline, which is a tetracycline antibiotic. Doxycycline is used to treat a variety of bacterial infections, including respiratory tract infections, urinary tract infections, and certain types of acne, among other indications. It works by inhibiting protein synthesis in bacteria, thereby preventing their growth and reproduction.

The other options listed are different classes of antibiotics and are used to treat various infections as well, but they do not correlate with the brand name Vibramycin. Amoxicillin, for instance, is a penicillin-type antibiotic; ciprofloxacin is a fluoroquinolone; and metronidazole is an antimicrobial drug used mostly for anaerobic infections. Each of these has its own unique mechanism of action and spectrum of activity, making doxycycline distinct as the correct answer in this context.