Doxycycline hyclate microbiology: Difference between revisions

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==Indications and Usage==
__NOTOC__
To reduce the development of drug-resistant bacteria and maintain the effectiveness of Doxycycline for Injection, USP and other antibacterial drugs, Doxycycline for Injection, USP should be used only to treat or prevent infections that are caused by susceptible bacteria.  When culture and susceptibility information are available, they should be considered in selecting or modifying antibacterial therapy.  In the absence of such data, local epidemiology and susceptibility patterns may contribute to the empiric selection of therapy.
{{Doxycycline hyclate}}
{{CMG}}; {{AE}} {{MM}}
==Microbiology==
Doxycycline inhibits bacterial protein synthesis by binding to the 30S ribosomal subunit. Doxycycline has bacteriostatic activity against a broad range of Gram-positive and Gram-negative bacteria. Cross resistance with other tetracyclines is common.
Doxycycline has been shown to be active against most isolates of the following microorganisms, both in vitro and in clinical infections as described in the INDICATIONS AND USAGE section of the package insert for VIBRAMYCIN.


Doxycycline for Injection, USP is indicated in infections caused by the following microorganisms:
*Gram-Negative Bacteria
Acinetobacter species
[[Bartonella bacilliformis]]
[[Brucella species]]
[[Calymmatobacterium granulomatis]]
[[Campylobacter fetus]]
[[Enterobacter aerogenes]]
[[Escherichia coli]]
[[Francisella tularensis]]
[[Haemophilus ducreyi]]
[[Haemophilus influenzae]]
[[Klebsiella species]]
[[Neisseria gonorrhoeae]]
[[Shigella species]]
[[Vibrio cholerae]]
[[Yersinia pestis]]


*Rickettsiae (Rocky Mountain spotted fever, typhus fever, and the typhus group, Q fever, rickettsial pox and tick fevers).
*Gram-Positive Bacteria
*Mycoplasma pneumoniae (PPLO, Eaton Agent).
*Agents of psittacosis and ornithosis.
*Agents of lymphogranuloma venereum and granuloma inguinale.
*The spirochetal agent of relapsing fever (Borelia recurrentis).


The following gram-negative microorganisms:
[[Bacillus anthracis]]
[[Streptococcus pneumoniae]]


*Haemophilus ducreyi (chancroid).
*Anaerobic Bacteria
*Pasteurella pestis and Pasteurella tularensis.
*Bartonella bacilliformis.
*Bacteroides species.
*Vibrio comma and Vibrio fetus.
*Brucella species (in conjunction with streptomycin).


Because many strains of the following groups of microorganisms have been shown to be resistant to tetracyclines, culture and susceptibility testing are recommended.
[[Clostridium species]]
[[Fusobacterium fusiforme]]
[[Propionibacterium acnes]]


Doxycycline is indicated for treatment of infections caused by the following gram-negative microorganisms when bacteriologic testing indicates appropriate susceptibility to the drug:
*Other Bacteria


*Escherichia coli.
[[Nocardiae]] and other aerobic Actinomyces species
*Enterobacter aerogenes (formerly Aerobacter aerogenes).
[[Borrelia recurrentis]]
*Shigella species.
[[Chlamydophila psittaci]]
*Mima species and Herellea species.
[[Chlamydia trachomatis]]
*Haemophilus influenzae (respiratory infections).
[[Mycoplasma pneumoniae]]
*Klebsiella species (respiratory and urinary infections).
[[Rickettsiae]]
[[Treponema pallidum]]
[[Treponema pertenue]]
[[Ureaplasma urealyticum]]


Doxycycline is indicated for treatment of infections caused by the following gram-positive microorganisms when bacteriologic testing indicates appropriate susceptibility to the drug:
*Parasites


*Anthrax due to Bacillus anthracis, including inhalational anthrax (post-exposure): to reduce the incidence or progression of disease following exposure to aerosolized Bacillus anthracis.
[[Balantidium coli]]
*Streptococcus species:
[[Entamoeba species]]
[[Plasmodium falciparum1]]


Up to 44% of strains of Streptococcus pyogenes and 74% of Streptococcus faecalis have been found to be resistant to tetracycline drugs.  Therefore, tetracyclines should not be used for streptococcal disease unless the organism has been demonstrated to be sensitive.


For upper respiratory infections due to group A beta-hemolytic streptococci, penicillin is the usual drug of choice, including prophylaxis of rheumatic fever.
Doxycycline has been found to be active against the asexual erythrocytic forms of Plasmodium falciparum, but not against the gametocytes of P. falciparum. The precise mechanism of action of the drug is not known.


*Diplococcus pneumoniae.
'''Susceptibility Testing Methods'''
*Staphylococcus aureus, respiratory, skin and soft tissue infections.  Tetracyclines are not the drugs of choice in the treatment of any type of staphylococcal infections.


When penicillin is contraindicated, doxycycline is an alternative drug in the treatment of infections due to:
When available, the clinical microbiology laboratory should provide the results of in vitro susceptibility test results for antimicrobial drugs used in resident hospitals to the physician as periodic reports that describe the susceptibility profile of nosocomial and community-acquired pathogens. These reports should aid the physician in selecting the most effective antimicrobial.


*Neisseria gonorrhoeae and N. meningitidis.
'''Dilution techniques'''
*Treponema pallidum and Treponema pertenue (syphilis and yaws).
*Listeria monocytogenes.
*Clostridium species.
*Fusobacterium fusiforme (Vincent’s infection).
*Actinomyces species.


In acute intestinal amebiasis, doxycycline may be a useful adjunct to amebicides.
Quantitative methods are used to determine antimicrobial minimum inhibitory concentrations (MICs). These MICs provide estimates of the susceptibility of bacteria to antimicrobial compounds. The MICs should be determined using a standardized test method1,2,4 (broth or agar). The MIC values should be interpreted according to criteria provided in Table 1.


Doxycycline is indicated in the treatment of trachoma, although the infectious agent is not always eliminated, as judged by immunofluorescence.<ref name="dailymed.nlm.nih.gov">{{Cite web  | last =  | first =  | title = DOXY 100 (DOXYCYCLINE) INJECTION, POWDER, LYOPHILIZED, FOR SOLUTION [APP PHARMACEUTICALS, LLC] | url = http://dailymed.nlm.nih.gov/dailymed/lookup.cfm?setid=b0894010-39bd-459f-8563-cf83343105ee | publisher =  | date =  | accessdate}}</ref>
'''Diffusion techniques'''
 
Quantitative methods that require measurement of zone diameters can also provide reproducible estimates of the susceptibility of bacteria to antimicrobial compounds. The zone size provides an estimate of the susceptibility of bacteria to antimicrobial compounds. The zone size should be determined using a standardized test method1,3,4. This procedure uses paper disks impregnated with 30-μg doxycycline to test the susceptibility of microorganisms to doxycycline. The disk diffusion interpretive criteria are provided in Table 1.
 
'''Anaerobic Techniques'''
 
For anaerobic bacteria, the susceptibility to doxycycline can be determined by a standardized test method5. The MIC values obtained should be interpreted according to the criteria provided in Table 1.
 
[[File:Doxycyclin table 1-1.jpg]]
 
[[File:Doxycyclin table 1-2.jpg]]
 
A report of Susceptible (S) indicates that the antimicrobial is likely to inhibit growth of the pathogen if the antimicrobial compound reaches the concentrations at the infection site necessary to inhibit growth of the pathogen. A report of Intermediate (I) indicates that the result should be considered equivocal, and, if the bacteria is not fully susceptible to alternative, clinically feasible drugs, the test should be repeated. This category implies possible clinical applicability in body sites where the drug product is physiologically concentrated or in situations where high dosage of drug can be used. This category also provides a buffer zone that prevents small uncontrolled technical factors from causing major discrepancies in interpretation. A report of Resistant (R) indicates that the antimicrobial is not likely to inhibit growth of the pathogen if the antimicrobial compound reaches the concentrations usually achievable at the infection site; other therapy should be selected.
 
'''Quality Control'''
 
Standardized susceptibility test procedures require the use of laboratory controls to monitor and ensure the accuracy and precision of the supplies and reagents used in the assay, and the techniques of the individuals performing the test1,2,3,4,5,6,7. Standard doxycycline and tetracycline powders should provide the following range of MIC values noted in Table 2. For the diffusion technique using the 30 mcg doxycycline disk the criteria noted in Table 2 should be achieved.
 
[[File:Doxy-table 2.jpg]]


==References==
==References==

Latest revision as of 02:02, 9 January 2014

Doxycycline hyclate
DOXY 100® FDA Package Insert
Description
Clinical Pharmacology
Microbiology
Indications and Usage
Contraindications
Warnings and Precautions
Adverse Reactions
Overdosage
Dosage and Administration
How Supplied
Labels and Packages

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Mohamed Moubarak, M.D. [2]

Microbiology

Doxycycline inhibits bacterial protein synthesis by binding to the 30S ribosomal subunit. Doxycycline has bacteriostatic activity against a broad range of Gram-positive and Gram-negative bacteria. Cross resistance with other tetracyclines is common. Doxycycline has been shown to be active against most isolates of the following microorganisms, both in vitro and in clinical infections as described in the INDICATIONS AND USAGE section of the package insert for VIBRAMYCIN.

  • Gram-Negative Bacteria

Acinetobacter species Bartonella bacilliformis Brucella species Calymmatobacterium granulomatis Campylobacter fetus Enterobacter aerogenes Escherichia coli Francisella tularensis Haemophilus ducreyi Haemophilus influenzae Klebsiella species Neisseria gonorrhoeae Shigella species Vibrio cholerae Yersinia pestis

  • Gram-Positive Bacteria

Bacillus anthracis Streptococcus pneumoniae

  • Anaerobic Bacteria

Clostridium species Fusobacterium fusiforme Propionibacterium acnes

  • Other Bacteria

Nocardiae and other aerobic Actinomyces species Borrelia recurrentis Chlamydophila psittaci Chlamydia trachomatis Mycoplasma pneumoniae Rickettsiae Treponema pallidum Treponema pertenue Ureaplasma urealyticum

  • Parasites

Balantidium coli Entamoeba species Plasmodium falciparum1


Doxycycline has been found to be active against the asexual erythrocytic forms of Plasmodium falciparum, but not against the gametocytes of P. falciparum. The precise mechanism of action of the drug is not known.

Susceptibility Testing Methods

When available, the clinical microbiology laboratory should provide the results of in vitro susceptibility test results for antimicrobial drugs used in resident hospitals to the physician as periodic reports that describe the susceptibility profile of nosocomial and community-acquired pathogens. These reports should aid the physician in selecting the most effective antimicrobial.

Dilution techniques

Quantitative methods are used to determine antimicrobial minimum inhibitory concentrations (MICs). These MICs provide estimates of the susceptibility of bacteria to antimicrobial compounds. The MICs should be determined using a standardized test method1,2,4 (broth or agar). The MIC values should be interpreted according to criteria provided in Table 1.

Diffusion techniques

Quantitative methods that require measurement of zone diameters can also provide reproducible estimates of the susceptibility of bacteria to antimicrobial compounds. The zone size provides an estimate of the susceptibility of bacteria to antimicrobial compounds. The zone size should be determined using a standardized test method1,3,4. This procedure uses paper disks impregnated with 30-μg doxycycline to test the susceptibility of microorganisms to doxycycline. The disk diffusion interpretive criteria are provided in Table 1.

Anaerobic Techniques

For anaerobic bacteria, the susceptibility to doxycycline can be determined by a standardized test method5. The MIC values obtained should be interpreted according to the criteria provided in Table 1.

A report of Susceptible (S) indicates that the antimicrobial is likely to inhibit growth of the pathogen if the antimicrobial compound reaches the concentrations at the infection site necessary to inhibit growth of the pathogen. A report of Intermediate (I) indicates that the result should be considered equivocal, and, if the bacteria is not fully susceptible to alternative, clinically feasible drugs, the test should be repeated. This category implies possible clinical applicability in body sites where the drug product is physiologically concentrated or in situations where high dosage of drug can be used. This category also provides a buffer zone that prevents small uncontrolled technical factors from causing major discrepancies in interpretation. A report of Resistant (R) indicates that the antimicrobial is not likely to inhibit growth of the pathogen if the antimicrobial compound reaches the concentrations usually achievable at the infection site; other therapy should be selected.

Quality Control

Standardized susceptibility test procedures require the use of laboratory controls to monitor and ensure the accuracy and precision of the supplies and reagents used in the assay, and the techniques of the individuals performing the test1,2,3,4,5,6,7. Standard doxycycline and tetracycline powders should provide the following range of MIC values noted in Table 2. For the diffusion technique using the 30 mcg doxycycline disk the criteria noted in Table 2 should be achieved.

References

Adapted from the FDA Package Insert.