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| PHARMACY BULK PACKAGE - NOT FOR DIRECT INFUSION |
Athenex
Rx only
To reduce the development of drug-resistant bacteria and maintain the effectiveness of ampicillin and other antibacterial drugs, Ampicillin for Injection, USP should be used only to treat or prevent infections that are proven or strongly suspected to be caused by bacteria.
Diffusion Techniques
Quantitative methods that require measurement of zone diameters provide reproducible estimates of the susceptibility of bacteria to antimicrobial compounds. One such standardized procedure1,2 that has been recommended for use with disks to test the susceptibility of microorganisms to ampicillin, uses the 10 mcg ampicillin disk. Interpretation involves correlation of the diameter obtained in the disk test with the minimum inhibitory concentration (MIC) for ampicillin. Reports from the laboratory providing results of the standard single-disk susceptibility test with a 10 mcg ampicillin disk should be interpreted according to the criteria provided in Table 1.
Dilution Techniques
Quantitative methods that are used to determine minimum inhibitory concentrations (MICs) provide reproducible estimates of the susceptibility of bacteria to antimicrobial compounds. One such standardized procedure1,3 uses a standardized dilution method (broth or agar) or equivalent with ampicillin powder. The MIC values obtained should be interpreted according to the criteria provided in Table 1.
| Susceptibility Test Result Interpretive Criteria | ||||||
| Pathogen | Disk diffusion (Zone diameter in mm) | Minimal Inhibitory Concentration (MIC in mcg/mL) | ||||
| S | I | R | S | I | R | |
| Enterobacteriaceae | ≥17 | 14 to 16 | ≤13 | ≤8 | 16 | ≥32 |
| Enterococcus spp. | ≥17 | - | ≤16 | ≤8 | - | ≥16 |
| Haemophilus influenzae and Haemophilus parainfluenzae | ≥22 | 19 to 21 | ≤18 | ≤1 | 2 | ≥4 |
| Streptococcus spp. (beta-hemolytic group) | ≥24 | - | - | ≤0.25 | - | - |
| Streptococcus spp. (viridans group) | - | - | - | ≤0.25 | 0.5 to 4 | ≥8 |
| Neisseria meningitidis | - | - | - | ≤0.12 | 0.25 to 1 | ≥2 |
Non-meningitidis S. pneumoniae isolates may be considered susceptible to ampicillin if the isolate has a penicillin MIC of ≤ 0.06 mcg/mL.
Susceptibility of staphylococci to ampicillin may be deduced from testing only penicillin and either cefoxitin or oxacillin.
A report of “Susceptible” (S) indicates that the pathogen is likely to be inhibited by usually achievable concentrations of the antimicrobial compound in the blood. A report of “Intermediate” (I) indicates that the result should be considered equivocal, if the microorganism 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 is physiologically concentrated or in situations where high dosage of the 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 pathogen is not likely to be inhibited if the antimicrobial compound in the blood reaches the concentrations usually achievable; other therapy should be selected.
Quality Control
Standardized susceptibility test procedures require the use of laboratory control microorganisms1,2,3.
The 10 mcg ampicillin disk and the standard ampicillin powder should provide respectively the following zone diameters and MIC values in these laboratory test quality control strains:
| Acceptable Quality Control Ranges | ||
| Microorganism | Disk diffusion (Zone diameter ranges in mm) | Minimal Inhibitory Concentration Range (MIC in mcg/mL) |
| Enterococcus faecalis ATCC® 29212 | 0.5 to 2 | |
| Escherichia coli ATCC® 25922 | 16 to 22 | 2 to 8 |
| Escherichia coli ATCC® 35218 | 6 | >32 |
| Haemophilus influenzae ATCC® 49247 | 13 to 21 | 2 to 8 |
| Staphylococcus aureus ATCC® 25923 | 27 to 35 | |
| Staphylococcus aureus ATCC® 29213 | 0.5 to 2 | |
| Streptococcus pneumoniae ATCC® 49619 | 30 to 36 | 0.06 to 0.25 |
Urethritis in males due to N. gonorrhoeae.
Adults - Two doses of 500 mg each at an interval of 8 to 12 hours. Treatment may be repeated if necessary or extended if required. In the treatment of complications of gonorrheal urethritis, such as prostatitis and epididymitis, prolonged and intensive therapy is recommended. Cases of gonorrhea with a suspected primary lesion of syphilis should have darkfield examinations before receiving treatment. In all other cases where concomitant syphilis is suspected, monthly serological tests should be made for a minimum of four months.
The doses for the preceding infections may be given by either the intramuscular or intravenous route. A change to oral ampicillin may be made when appropriate.
Bacterial Meningitis
Adults and children - 150 to 200 mg/kg/day in equally divided doses every 3 to 4 hours. (Treatment may be initiated with intravenous drip therapy and continued with intramuscular injections.) The doses for other infections may be given by either the intravenous or intramuscular route.
Neonates (less than or equal to 28 days of postnatal age) - Dosage should be based on Gestational age and Postnatal age according to Table 3.
| Gestational age (weeks) | Postnatal age (days) | Dosage |
| less than or equal to 34 | less than or equal to 7 | 100 mg/kg/day in equally divided doses every 12 hours |
| less than or equal to 34 | greater than or equal to 8 and less than 28 | 150 mg/kg/day in equally divided doses every 12 hours |
| greater than 34 | less than or equal to 28 | 150 mg/kg/day in equally divided doses every 8 hours |
Septicemia
Adults and children: 150 to 200 mg/kg/day. Start with intravenous administration for at least three days and continue with the intramuscular route every 3 to 4 hours.
Neonates (less than or equal to 28 days of postnatal age) - Dosage should be based on Gestational age and Postnatal age according to Table 3 (above).
Treatment of all infections should be continued for a minimum of 48 to 72 hours beyond the time that the patient becomes asymptomatic or evidence of bacterial eradication has been obtained. A minimum of 10-days treatment is recommended for any infection caused by Group A beta-hemolytic streptococci to help prevent the occurrence of acute rheumatic fever or acute glomerulonephritis.