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Streptomycin (Streptomycin) - Description and Clinical Pharmacology



To reduce the development of drug-resistant bacteria and maintain the effectiveness of streptomycin and other antibacterial drugs, streptomycin should be used only to treat or prevent infections that are proven or strongly suspected to be caused by bacteria.


Streptomycin is a water-soluble aminoglycoside derived from Streptomyces griseus. It is marketed as the sulfate salt of streptomycin. The chemical name of streptomycin sulfate is D-Streptamine, O-2-deoxy-2-(methylamino)-α-L-glucopyranosyl-(1→2)-O-5-deoxy-3-C-formyl-α-L-lyxofuranosyl-(1→4)-N,N 1-bis(aminoiminomethyl)-,sulfate (2:3) (salt). The molecular formula for Streptomycin Sulfate is (C21H39N7O12)2 -3H2SO4 and the molecular weight is 1457.41. It has the following structural formula:

structural formula

structural formula

Streptomycin for Injection USP, equivalent to 1 gram streptomycin /vial is supplied as a sterile nonpyrogenic lyophillized cake for intramuscular use after reconstitution. The lyophillized cake may reduce to a powder during shipping.

After reconstitution the pH range for Streptomycin for Injection USP should be between 4.5 and 7 in a solution containing 200 mg of streptomycin activity per mL.

*Each vial of Streptomycin for Injection contains streptomycin sulfate equivalent to 1 gram of streptomycin.


Following intramuscular injection of 1 g of streptomycin as the sulfate, a peak serum level of 25 to 50 mcg/mL is reached within 1 hour, diminishing slowly to about 50 percent after 5 to 6 hours.

Appreciable concentrations are found in all organ tissues except the brain. Significant amounts have been found in pleural fluid and tuberculous cavities. Streptomycin passes through the placenta with serum levels in the cord blood similar to maternal levels. Small amounts are excreted in milk, saliva, and sweat.

Streptomycin is excreted by glomerular filtration. In patients with normal kidney function, between 29% and 89% of a single 600 mg dose is excreted in the urine within 24 hours. Any reduction of glomerular function results in decreased excretion of the drug and concurrent rise in serum and tissue levels


Streptomycin sulfate is a bactericidal antibiotic. It acts by interfering with normal protein synthesis.

Streptomycin has been shown to be active against most strains of the following organisms both in vitro and in clinical infection. (See INDICATIONS AND USAGE.):

  • Brucella (brucellosis),

  • Calymmatobacterium granulomatis (donovanosis, granuloma inguinale),

  • Escherichia coli, Proteus spp., Aerobacter aerogenes, Klebsiella pneumoniae, and Enterococcus faecalis in urinary tract infections,

  • Francisella tularensis,

  • Haemophilus ducreyi (chancroid),

  • Haemophilus influenzae (in respiratory, endocardial, and meningeal infections - concomitantly with another antibacterial agent),

  • Klebsiella pneumoniae pneumonia (concomitantly with another antibacterial agent),

  • Mycobacterium tuberculosis,

  • Pasteurella pestis

  • Streptococcus viridans, Enterococcus faecalis (in endocardial infections - concomitantly with penicillin).

SUSCEPTIBILITY TESTS: Diffusion Techniques

Quantitative methods that require measurement of zone diameters give the most precise estimate of the susceptibility of bacteria to antimicrobial agents. One such standard procedure 1 which has been recommended for use with disks to test susceptibility of organisms to streptomycin uses the 10 mcg streptomycin disk. Interpretation involves the correlation of the diameter obtained in the disk test with the minimum inhibitory concentration (MIC) for streptomycin.

Reports from the laboratory giving results of the standard single disk susceptibility test with a 10 mcg streptomycin disk should be interpreted according to the following criteria:

Interpretive Criteria for Enterobacteriaceae 

 Zone Diameter (mm)      Interpretation
 ≥15  (S) Susceptible
 11-12  (I) Intermediate
 ≤10  (R) Resistant

A report of “Susceptible” indicates that the pathogen is likely to respond to monotherapy with streptomycin. A report of “Intermediate” indicates that the result be considered equivocal, and, if the organism is not fully susceptible to alternative clinically feasible drugs, the test should be repeated. This category provides a buffer zone which prevents small uncontrolled technical factors from causing major discrepancies in interpretations. A report of “Resistant” indicates that achievable drug concentrations are unlikely to be inhibitory and other therapy should be selected.

Standardized procedures require the use of laboratory control organisms. The 10 mcg streptomycin disk should give the following zone diameter2:

Acceptable Control Ranges 

 Organism  Zone Diameter (mm)
 E. coli ATCC 25922  12-20

Interpretive Criteria for Agents of Bioterrorism 

Organism      MIC Range (mcg/mL) 
  (S) Susceptible (I) Intermediate  (R) Resistant
Yersinia pestis  ≤4   8  ≥16
Francisella tularensis ≤8

There are no Intermediate or Resistant criteria

Brucella spp. ≤8

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