Tetracycline is a broad-spectrum
polyketide antibiotic produced by the Streptomyces genus of Actinobacteria,
indicated for use against many bacterial infections. It is a protein synthesis
inhibitor. It is commonly used to treat acne today, and, more recently, rosacea,
and is historically important in reducing the number of deaths from cholera.
The term "tetracycline" is also used to
denote the four-ring system of this compound; "tetracyclines" are related
substances that contain the same four-ring system.
Used to treat bacterial infections such
as Rocky Mountain spotted fever, typhus fever, tick fevers, Q fever,
rickettsialpox and Brill-Zinsser disease. May be used to treat infections caused
by Chlamydiae spp., B. burgdorferi (Lyme disease), and upper
respiratory infections caused by typical (S. pneumoniae, H. influenzae,
and M. catarrhalis) and atypical organisms (C. pneumoniae, M.
pneumoniae, L. pneumophila). May also be used to treat acne.
Tetracycline may be an alternative drug for people who are allergic to
Tetracycline hydrochloride is indicated
for the treatment of the following infections:
Rocky Mountain spotted fever, typhus fever and the typhus group, Q fever,
rickettsial pox and tick fever caused by Rickettsiae.
Respiratory tract infections caused by Mycoplasma pneumoniae.
Lymphogranuloma venereum caused by Chlamydia trachomatis.
Psittacosis and ornithosis due to Chlamydia psittaci.
Trachoma caused by Chlamydia trachomatis, although the infectious agent
is not always eliminated, as judged by immuno- fluorescence.
Inclusion conjunctivitis caused by Chlamydia trachomatis.
Tetracycline hydrochloride is indicated for the treatment of uncomplicated
urethral, endocervical or rectal infections in adults caused by Chlamydia
Nongonococcal urethritis caused by Ureaplasma urealyticum. Relapsing
fever due to Borrelia recurrentis.
Tetracycline hydrochloride is also indicated for the treatment of infections
caused by the following gram-negative microorganisms:
Chancroid caused by Haemophilus ducreyi.
Plague due to Yersinia pestis (formerly Pasteurella pestis).
Tularemia due to Francisella tularensis (formerly Pasteurella
Cholera caused by Vibrio cholerae (formerly Vibrio comma).
Campylobacter fetus infections caused by Campylobacter fetus (formerly
Brucellosis due to Brucella species (in conjunction with streptomycin).
Bartonellosis due to Bartonella bacilliformis.
Granuloma inguinale caused by Calymmatobacterium granulomatis.
Because many strains of the following groups of microorganisms have been shown
to be resistant to tetracycline hydrochloride, culture and susceptibility
testing are recommended.
Tetracycline hydrochloride is indicated for treatment of infections caused by
the following gram-negative microorganisms, when bacteriologic testing indicates
appropriate susceptibility to the drug:
Bioavailability is less than 40% when
administered via intramuscular injection, 100% intravenous, and 60-80% oral
(fasting adults). Food and/or milk reduce GI absorption of oral preparations of
tetracycline by 50% or more.
Mechanism of action
Tetracycline is a short-acting
antibiotic that inhibits bacterial growth by inhibiting translation. It binds to
the 30S ribosomal subunit and prevents the amino-acyl tRNA from binding to the A
site of the ribosome. It also reversibly binds to the 50S ribosomal
subunit. Moreover, tetracycline may alter the cytoplasmic membrane of bacteria
causing leakage of intracellular contents, such as nucleotides, from the cell.
Tetracycline passively diffuses through porin channels in the bacterial