Tetracycline (Sumycin, Tetracyn, Panmycin)


  • Antibiotic


  • Tetracycline antibiotic


  • Rickettsiae infections (Rocky Mtn spotted fever, typhus fever, Q fever, rickettsialpox and tick fevers)

  • Mycoplasma pneumoniae infections

  • Psittacosis and ornithosis

  • Lymphogranuloma venereum and granuloma inguinale

  • Borrelia recurrentis infections

  • Gram-negative infections (E. coli, Enterobacter aerogenes, Shigella species, Acinetobacter calcoaceticus, H. influenzae, Klebsiella species,H. ducreyi, Yersinia pestis, Francisella tularensis, Bartonella bacilliformis, Bacteroides species, Campylobacter fetus, V. cholerae, Brucella species)

  • Gram-positive infections (Streptococcus species, S. pyogenes, S. faecalis)

  • For infections were penicillin is the drug-of-choice but is contraindicated (N. gonorrhoeae, Treponema pallidum, T. pertenue, Listeria monocytogenes, Clostridium species, Bacillus anthracis, Fusobacterium fusiforme, Actinomyces species,  N. meningitidis)

  • Acute intestinal amebiasis

  • Acne

  • Inclusion conjunctivitis

  • Chlamydia trachomatis

  • Lyme disease (Borrelia burgdorferi)


  • None


  • Pregnancy category D

  • Do not use in last half of pregnancy up to 8 years old due to tooth discoloration

  • May cause photosensitivity reactions

  • Prolonged intraveneous (IV) administration may lead to thrombophlebitis, initiate oral therapy as soon as possible

  • Doses greater than 2 grams per day may lead to hepatic function impairment

  • Excreted in breast milk

  • May cause pseudotumor cerebri (benign intracranial hypertension with symptoms of headache and blurred vision)

  • Do not use after expiration date.  Degraded, expired tetracyclines are highly nephrotoxic.

  • Administer on an empty stomach, 1 hour before or 2 hours after meals

  • Do not take with antacids, iron, aluminum, magnesium or zinc preparations, milk or dairy products

  • Take with a full glass of water and remain standing for at least 90 seconds and/or lay down for 60 minutes to decrease occurrence of esophageal ulcers.

  • Complete full course of therapy.

Adverse Reactions (Side Effects):

  • Anorexia, nausea, vomiting, diarrhea, epigastric distress, loose stools, sore throat

  • Esophageal ulcers

  • Fatty liver, hepatotoxicity, increased BUN levels

  • Urticaria

  • Local injection site pain  


Administered orally (capsules and suspension) and by IV injection

  • Adults:

    • Oral: 1-2 grams per day in 2-4 equal doses

    • Parenteral: 250-500mg q12h

    • Mild/moderate infections: 250mg po qid or 500mg po bid

    • Severe infections: 500mg po qid

  • Children (>8 years old):

    • Oral: 25-50mg/kg/day in 4 equal doses

    • Pareneteral: 10-20mg/kg/day (average 12mg/kg/day) in 2 divided doses

  • Brucellosis: 

    • 500mg qid for 3 weeks, followed by 1 gram streptomycin

  • Syphilis: 

    • 30-40grams in equally divided doses over 10-15 days

  • Gonorrhea: 

    • 1.5 gram initially, then 500mg every 6 hours up to a total of 9 grams

  • Chlamydia trachomatis infections: 

    • 500mg four times a day for at least 7 days

  • Severe acne: 

    • 1 gram per day in divided doses initially, then 125-500mg per day

  • Lower resp, skin, bone or joint infection (mild/moderate): 

    • 500mg po q12h or 400mg IV q12h

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