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A. Mechanismsnavigator

  1. Agents inhibit bacterial protein translation
  2. Bind to bacterial 30S ribosome subunit
  3. Agents are bacterostatic
  4. Resistance
    1. Mainly develops by mutations in 30S ribosome
    2. Bacterial efflux pumps lead to resistance as well
  5. Glycylcyclines have been developed to overcome major resistance mechanisms
  6. Tetracyclines appear to have immunomodulatory activity
    1. Efficacy in acne may be due to antibiotic and immunodulatory activity
    2. Efficacy of minocycline in rheumatoid arthritis may be due to immunomodulation
  7. Should not be used in pregnancy

B. Spectrum of Tetracyclinesnavigator

  1. Good Gram positive coverage
    1. Many strains of Staphylococcus aureus (even MRSA)
    2. Enterococci including some resistant to vancomycin (VREF)
    3. May be used in combination with rifampin to eradicate fecal VREF
    4. Resistance is increasing in pneumococcus
    5. Reasonable choices for community acquired pneumonia
  2. Excellent coverage atypical organisms
    1. Chlamydia trachomatis
    2. Ureaplasma urealyticum (and many strains of mycoplasma)
    3. Mycoplasma pneumoniae (most common cause of pneumonia in young persons)
    4. Chlamydia pneumoniae
    5. Rickettsiae and Bartonella
    6. Borrelia ssp, including Lyme Disease
    7. Treponema pallidum (Syphilis)
    8. Leptospira
    9. Mycobacterium marinum
    10. Activity against anthrax and tularemia [2]
  3. Covers some gram negative organisms, but unreliable
  4. Other Uses
    1. Acne
    2. Sclerosing agent for treatment of malignant pleural effusions
    3. Malaria therapy
  5. Glycylcyclines (tigecycline) can be used for complicated skin and intra-abdominal infections

C. Tetracyclinenavigator

  1. Use only in persons >8 years old (causes teeth discoloration in younger persons)
  2. Dose is 500mg po qid for most applications; 250mg qid for acne
  3. Inconvenient dosing but very low price
  4. Contraindicated in pregnancy

D. Doxycycline (Vibramycin® and others)navigator

  1. Well tolerated, convenient
  2. 100mg po or IV bid dosing
  3. For community acquired pneumonia, doxycycline 100mg IV q12 hours may be as or more effective as "broader" agents and is considerably less expensive [3]
  4. Active against most strains of anthrax and tularemia [2]
  5. Prophylaxis after tick bite for preventing Lyme disease in endemic areas [7]
  6. Prophylaxis after tick bite for preventing tick-borne relapsing fever [8]
  7. Contraindicated in pregnancy and in children <9 years old

E. Minocycline (Minocin®, Dynacin®, extended release Solodyn®)navigator

  1. Approved for nongonococcal urethritis / mucopurulent cervicitis
  2. Activity and approved in common acne
  3. Mild activity in rheumatoid arthritis
  4. Prolonged use may cause ANA+ and mild lupus (rash, arthritis, livedo reticularis)
  5. Prolonged use may also cause other autoimmune disorders with pANCA+ [4]
  6. Side Effects (may be more pronounced with immediate release)
    1. Photosensitivity
    2. Steatohepatitis
    3. Vertigo (less in extended release)
    4. Contraindicated in pregnancy and in children <9 years old (effects on bone and teeth)
    5. Pill induced esophageal ulceration (odynophagia)
    6. Yellow discoloration of teeth, particularly in children
    7. Increases prothrombin time with warfarin therapy

F. Tigecycline (Tygacil®) [5,6]navigator

  1. Glycylcycline, derivative of minocycline
  2. Inhibits translation by binding bacterial 30S ribosome
  3. Not affected by most mutations causing tetracycline resistance
  4. Not susceptible to bacterial efflux pumps
  5. Generally considered bacteriostatic
  6. Approved for:
    1. Complicated skin and soft tissue (skin structure) infections
    2. Complicated intra-abdominal infections
    3. Similar efficacy to vancomycin/aztreoman in skin and soft tissue infections
    4. Similar efficacy to imipenam/cilistatin in complicated intra-abdominal infections
  7. Activity
    1. Excellent staphylococcal (including MRSA) and streptococcal coverage
    2. Vancomycin susceptible Enterococcus faecalis
    3. Anaerobes: Bacteroides ssp, Clostrium perfringes, Peptostreptococcus micros
    4. Gram negative coverage is very good
  8. Dose:
    1. Adults: 100mg IV initial, then 50mg q12 hours (all given over 30-60 minutes)
    2. Severe hepatic impairment: 100mg IV initial, then 25mg q12 hours
    3. Not for children
    4. Only intravenous (IV) forms available

References navigator

  1. Joshi N and Miller DQ. 1997. Arch Intern Med. 157(13):1421 abstract
  2. Drugs and Vaccines Against Biological Weapons. 2001. Med Let. 43(1115):87 abstract
  3. Ailani RK, Agastya G, Ailani RK, et al. 1999. Arch Intern Med. 159(3):266 abstract
  4. Elkayam O, Levartovsky D, Brautbar C, et al. 1998. Am J Med. 105(6):484 abstract
  5. Tigecycline. 2005. Med Let. 47(1217):73 abstract
  6. Community Acquired MRSA. 2006. Med Let. 48(1228):13 abstract
  7. Hayes EB and Piesman J. 2003. NEJM. 348(24):2424 abstract
  8. Hasin T, Davidovitch N, Cohen R, et al. 2006. NEJM. 35592):148
  9. Extended Release Minocycline. 2006. Med Let. 48(1248):95 abstract