To reduce the development of drug- resistant bacteria and maintain the effectiveness of Doxycycline Hyclate Tablets, USP and other antibacterial drugs, Doxycycline Hyclate Tablets, USP should be used only to treat or prevent infections that are proven or strongly suspected to be caused by susceptible bacteria. what does doxycycline do Bala HR, Lee S, Wong C, Pandya AG, Rodrigues M.