are doxycycline and tetracycline the same?
What are doxycycline and tetracycline? Doxycycline is a synthetic (man-made) antibiotic derived from tetracycline. Doxycycline is used for many different types of infections, including respiratory tract infections due to Hemophilus influenzae, Streptococcus pneumoniae, or Mycoplasma pneumoniae.