The U.S. FDA Wednesday finalized its 2017 guidance on extending the expiration dates for doxycycline tablets and capsules held in state and local strategic stockpiles for use as a post-exposure prophylaxis or treatment of inhalational anthrax. The guidance applies to both doxycycline monohydrate and doxycycline hyclate tablets and capsules equivalent to 50 mg and 100 mg of doxycycline, the FDA said.