Bacterial infections:

Indications for Doxycycline Monohydrate Tablets:

Tetracycline-susceptible infections including respiratory, genitourinary, rickettsial, trachoma. Postexposure prophylaxis and treatment of anthrax.


Usual dose: 200mg on first day (give as 100mg every 12hrs or 50mg every 6hrs) followed by maintenance dose of 100mg/day (may be given as a single dose or as 50mg every 12hrs). Management of severe infections (including chronic UTI): 100mg every 12hrs. Uncomplicated gonoccal infections (except anorectal infections in men): 100mg twice daily for 7 days or 300mg stat followed in one hour by a second 300mg dose. Acute epididymo-orchitis caused by N. gonorrhoeae, C. trachomatis: 100mg twice daily for at least 10 days. Primary and secondary syphilis: 300mg in divided doses for at least 10 days. Uncomplicated urethral, endocervical, or rectal infection caused by C. trachomatis, nongonococcal urethritis caused by C. trachomatis and U. urealyticum: 100mg twice daily for at least 7 days. Inhalational anthrax (post-exposure): 100mg twice daily for 60 days.


<8yrs: not recommended. >8yrs: ≤100lbs: 2mg/lb divided into two doses on the first day, followed by 1mg/lb as a single daily dose or divided into two doses, on subsequent days. Severe infections: up to 2mg/lb may be used. >100lbs: use adult dose. Inhalational anthrax (post-exposure): ≤100lbs: 1mg/lb twice daily for 60 days. >100lbs: use adult dose.


Monitor blood, renal, and liver function in long-term use. Avoid excessive sunlight or UV light. Pregnancy (Cat.D), nursing mothers: not recommended.

Pharmacologic Class:

Tetracycline antibiotic.


Antacids, iron, zinc, calcium, magnesium reduce absorption. Avoid concomitant penicillin, methoxyflurane. Carbamazepine, phenytoin, barbiturates may decrease effectiveness. Monitor prothrombin time with oral anticoagulants. May decrease effectiveness of oral contraceptives.

Adverse Reactions:

Photosensitivity, GI upset, esophageal irritation/ulceration (drink fluids liberally with dose), rash, increased BUN, hypersensitivity reactions, blood dyscrasias; pseudomembranous colitis.

How Supplied:

Tabs 50mg—100; 100mg—50, 250