<prompt> Drug of choice for plague is:ErythromycinTetracyclinesAmpicillinCotrimoxazole  <response>: TETRACYCLINES: These are a class of antibiotics having a nucleus of four cyclic rings. Tetracyclines are the first choice drugs. despite development of resistance by many organisms in: avenereal diseases chlamydial non specific urethritisendocervicitis: 7 day doxycycline treatment is as effective as azithromycin single dose. Lymphogranuloma venereum: resolves in 2-3 weeks Granuloma inguinale:Due to Calymm granulomatis: a tetracycline administered for 3 weeks is the most effective treatment. b Atypical pneumonia: due to Mycoplasma pneumoniae: duration of illness is reduced by tetracycline therapy. Psittacosis is treated in 2 weeks by tetracyclines. ; c cholera: Tetracyclines have adjuvant value by reducing stool volume and limiting the duration of diarrhoea. dbrucellosis: Tetracyclines are highly efficacious; cause rapid symptomatic relief; therapy of choice is doxycycline 200 mg day rifampin 600 mg day for 6 weeks. Gentamicin may be combined with doxycycline in acute cases. eplague: Tetracyclines are highly effective in both bubonic and pneumonic plague. They are preferred for blind mass treatment of suspected cases during an epidemic, though streptomycin often acts faster. j Relapsing fever due to Borrelia recurrentis responds adequately. g Rickettsial infections: typhus, rocky mountain spotted fever, Q fever, etc. respond dramatically. Chloramphenicol is an alternative. ESSENTIALS OF MEDICAL PHARMACOLOGY K.D.TRIPATHI SIXTH EDITION PAGE NO:714,715 