Microbiology

While in vitro studies have demonstrated the susceptibility of most strains of the following organisms, clinical efficacy for infections other than those included in the INDICATIONS AND USAGE section has not been demonstrated.

Antibacterial Activity

The following bacteria have been shown in in vitro studies to be susceptible to ampicillin for injection:

Gram-positive Bacteria

Hemolytic and nonhemolytic streptococci

Streptococcus pneumoniae

Nonpenicillinase-producing staphylococci

Clostridium spp.

B. anthracis

Listeria monocytogenes

Most strains of enterococci.

Gram-negative Bacteria

H. influenzae

N. gonorrhoeae

N. meningitidis

Proteus mirabilis

Many strains of Salmonella, Shigella, and E. coli.

AMPICILLIN does not resist destruction by penicillinase.

Susceptibility Testing

For specific information regarding susceptibility test interpretive criteria and associated test methods and quality control standards recognized by FDA for this drug, please see: https://www.fda.gov/STIC.

General

The possibility of superinfections with mycotic organisms or bacterial pathogens should be kept in mind during therapy. In such cases, discontinue the drug and substitute appropriate treatment.

A high percentage (43 to 100 percent) of patients with infectious mononucleosis who receive ampicillin develop a skin rash. Typically, the rash appears 7 to 10 days after the start of oral ampicillin therapy and remains for a few days to a week after the drug is discontinued. In most cases, the rash is maculopapular, pruritic, and generalized. Therefore, the administration of ampicillin is not recommended in patients with mononucleosis. It is not known whether these patients are truly allergic to ampicillin.

Prescribing ampicillin in the absence of a proven or strongly suspected bacterial infection or a prophylactic indication is unlikely to provide benefit to the patient and increases the risk of the development of drug-resistant bacteria.

Information for Patients

Patients should be counseled that antibacterial drugs including ampicillin should only be used to treat bacterial infections. They do not treat viral infections (e.g., the common cold). When ampicillin is prescribed to treat a bacterial infection, patients should be told that although it is common to feel better early in the course of therapy, the medication should be taken exactly as directed. Skipping doses or not completing the full course of therapy may: (1) decrease the effectiveness of the immediate treatment, and (2) increase the likelihood that bacteria will develop resistance and will not be treatable by ampicillin or other antibacterial drugs in the future.

Diarrhea is a common problem caused by antibiotics which usually ends when the antibiotic is discontinued. Sometimes after starting treatment with antibiotics, patients can develop watery and bloody stools (with or without stomach cramps and fever) even as late as two or more months after having taken the last dose of the antibiotic. If this occurs, patients should contact their physician as soon as possible.

Laboratory Tests

As with any potent drug, periodic assessment of organ system function, including renal, hepatic, and hematopoietic, should be made during prolonged therapy.

Transient elevation of serum transaminase has been observed following administration of ampicillin. The significance of this finding is not known.

Drug Interactions

The concurrent administration of allopurinol and ampicillin increases substantially the incidence of skin rashes in patients receiving both drugs as compared to patients receiving ampicillin alone. It is not known whether this potentiation of ampicillin rashes is due to allopurinol or the hyperuricemia present in these patients.

Drug/Laboratory Test Interactions

With high urine concentrations of ampicillin, false-positive glucose reactions may occur if Clinitest, Benedict’s Solution, or Fehling’s Solution are used. Therefore, it is recommended that glucose tests based on enzymatic glucose oxidase reactions (such as Clinistix or Tes-Tape) be used.

Carcinogenesis, Mutagenesis, and Impairment of Fertility

No long-term animal studies have been conducted with this drug.

Pregnancy

Reproduction studies have been performed in laboratory animals at doses several times the human dose and have revealed no evidence of adverse effects due to ampicillin. There are, however, no adequate and well-controlled studies in pregnant women. Because animal reproduction studies are not always predictive of human response, this drug should be used during pregnancy only if clearly needed.

Labor and Delivery

Oral ampicillin-class antibiotics are poorly absorbed during labor. Studies in guinea pigs showed that intravenous administration of ampicillin slightly decreased the uterine tone and frequency of contractions, but moderately increased the height and duration of contractions. However, it is not known whether use of these drugs in humans during labor or delivery has immediate or delayed adverse effects on the fetus, prolongs the duration of labor, or increases the likelihood that forceps delivery or other obstetrical intervention or resuscitation of the newborn will be necessary.

Nursing Mothers

Ampicillin is excreted in trace amounts in human milk. Therefore, caution should be exercised when ampicillin-class antibiotics are administered to a nursing woman.

Pediatric Use

Guidelines for the administration of these drugs to children, including neonates are presented in DOSAGE AND ADMINISTRATION section.

Gastrointestinal

Glossitis, stomatitis, black “hairy” tongue, nausea, vomiting, enterocolitis, pseudomembranous colitis, and diarrhea. (These reactions are usually associated with oral dosage forms.)

Hypersensitivity Reactions

Skin rashes and urticaria have been reported frequently. A few cases of exfoliative dermatitis and erythema multiforme have been reported. Linear IgA bullous dermatosis has been reported. Anaphylaxis is the most serious reaction experienced and has usually been associated with the parenteral dosage form.

Note: Urticaria, other skin rashes, and serum sickness-like reactions may be controlled with antihistamines and, if necessary, systemic corticosteroids. Whenever such reactions occur, ampicillin should be discontinued, unless, in the opinion of the physician, the condition being treated is life-threatening and amenable only to ampicillin therapy. Serious anaphylactic reactions require the immediate use of epinephrine, oxygen, and intravenous steroids.

Liver – A moderate rise in serum glutamic oxaloacetic transaminase (SGOT) has been noted, particularly in infants, but the significance of this finding is unknown. Mild transitory SGOT elevations have been observed in individuals receiving larger (two to four times) than usual and oft-repeated intramuscular injections. Evidence indicates that glutamic oxaloacetic transaminase (GOT) is released at the site of intramuscular injection of ampicillin sodium and that the presence of increased amounts of this enzyme in the blood does not necessarily indicate liver involvement.

Hemic and Lymphatic Systems – Anemia, thrombocytopenia, thrombocytopenic purpura, eosinophilia, leukopenia, and agranulocytosis have been reported during therapy with the penicillins. These reactions are usually reversible on discontinuation of therapy and are believed to be hypersensitivity phenomena.

Central Nervous System - Seizures

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 1.

Table 1: Dosage in Neonates (less than or equal to 28 days of postnatal age) for Bacterial Meningitis and Septicemia

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 1 (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.

DIRECTION FOR USE

For Administration by Intravenous Infusion – Reconstitute as directed below (see Directions for Proper Use of Pharmacy Bulk Package) prior to diluting with an intravenous solution.

IMPORTANT: This chemical stability information in no way indicates that it would be acceptable practice to use this product well after the preparation time. Good professional practice suggests that compounded admixtures should be administered as soon after preparation as is feasible.

Stability studies on ampicillin sodium at several concentrations in various intravenous solutions indicate the drug will lose less than 10% activity at the temperatures noted for the time periods stated.

Only those solutions listed above should be used for the intravenous infusion of ampicillin for injection, USP. The concentrations should fall within the range specified. The drug concentration and the rate and volume of the infusion should be adjusted so that the total dose of ampicillin is administered before the drug loses its stability in the solution in use.

Directions for Proper Use of Pharmacy Bulk Package

This Pharmacy Bulk Package glass bottle contains ampicillin sodium equivalent to 10 grams of ampicillin. It is designed for use in the pharmacy in preparing intravenous admixtures using aseptic technique in a laminar flow hood.

a) Add 94 mL Sterile Water for Injection USP. The resulting solution will contain 100 milligrams ampicillin activity per mL, and is stable up to ONE hour at room temperature.

b) Dilute further within ONE hour to a concentration of 5 mg to 10 mg per mL. See Table for suitable fluid. Use promptly. This chemical stability information in no way indicates that it would be acceptable practice to use this product well after preparation time. Good professional practice suggests that compounded admixtures should be administered as soon after preparation as is feasible.

c) Using aseptic technique under a laminar flow hood, the closure should be penetrated only one time after reconstitution using a suitable sterile dispensing set; which allows measured dispensing of the contents. Use of a syringe and needle is not recommended as it may cause leakage.

d) After entry, use entire contents of bottle promptly. The entire contents of the Pharmacy Bulk Package must be dispensed within ONE hour of reconstitution. This time limit should begin with the introduction of solvent or diluent into the Pharmacy Bulk Package.

Use of this product is restricted to a suitable work area, such as a laminar flow hood. Parenteral drug products should be inspected visually for particulate matter and discoloration prior to administration, whenever solution and container permit.

CAUTION: NOT TO BE DISPENSED AS A UNIT.