Ampicillin Capsules, USP

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

Ampicillin trihydrate is a semisynthetic penicillin derived from the basic penicillin nucleus, 6- aminopenicillanic acid. Ampicillin is designated chemically as (2S, 5R, 6R)-6-[(R)-2-Amino-2-phenylacetamido]-3,3- dimethyl-7-oxo-4-thia-1-azabicyclo [3.2.0] heptane-2- carboxylic acid. Its structural formula is:

Ampicillin Capsules, USP for oral administration provide ampicillin trihydrate equivalent to 250 mg and 500 mg ampicillin. Inactive ingredients: black iron oxide, gelatin, magnesium stearate and titanium dioxide.

Ampicillin is bactericidal at low concentrations and is clinically effective not only against the gram-positive organisms usually susceptible to penicillin G but also against a variety of gram-negative organisms. It is stable in the presence of gastric acid and is well absorbed from the gastrointestinal tract. It diffuses readily into most body tissues and fluids; however, penetration into the cerebrospinal fluid and brain occurs only with meningeal inflammation. Ampicillin is excreted largely unchanged in the urine; its excretion can be delayed by concurrent administration of probenecid which inhibits the renal tubular secretion of ampicillin. In blood serum, ampicillin is the least bound of all the penicillins; an average of about 20 percent of the drug is bound to plasma proteins as compared to 60 to 90 percent of the other penicillins. The administration of 500 mg dose of ampicillin capsules results in an average peak blood serum level of approximately 3.0 mcg/mL.

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 documented.

GRAM-POSITIVE – strains of alpha- and beta-hemolytic streptococci, Streptococcus pneumoniae, those strains of staphylococci, which do not produce penicillinase, Clostridium sp., Bacillus anthracis, Corynebacterium xeroses, and most strains of enterococci.

GRAM-NEGATIVE – Hemophilus influenzae; Neisseria gonorrhoeae and N. Meningitides; Proteus mirabilis, and many strains of Salmonella (including S. typhosa), Shigella, and Escherichia coli.

NOTE: Ampicillin is inactivated by penicillinase and therefore is ineffective against penicillinase-producing organisms including certain strains of staphylococci, Pseudomonas aeruginosa, P. Vulgaris, Klebsiella pneumoniae, Enterobacter aerogenes, and some strains of E. coli. Ampicillin is not active against Rickettsia, Mycoplasma, and “large viruses” (Miyagawanella).

TESTING FOR SUSCEPTIBILITY: The invading organism should be cultured and its susceptibility demonstrated as a guide to therapy. If the Kirby-Bauer method of disc susceptibility is used, a 10 mcg ampicillin disc should be used to determine the relative in vitro susceptibility.

Ampicillin Capsules, USP are indicated in the treatment of infections caused by susceptible strains of the designated organism listed below:

INFECTIONS OF THE GENITOURINARY TRACT INCLUDING GONORRHEA: E. coli, P. mirabilis, enterococci, Shigella, S. typhosa and other Salmonella, and nonpenicillinaseproducing N. gonorrhoeae.

INFECTIONS OF THE RESPIRATORY TRACT: Nonpenicillinase- producing H. influenzae and staphylococci, and streptococci including streptococcus pneumoniae.

INFECTIONS OF THE GASTROINTESTINAL TRACT:

Shigella, S. typhosa and other Salmonella, E. coli, P. mirabilis, and enterococci.

MENINGITIS: N. Meningitides.

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

Bacteriology studies to determine the causative organisms and their susceptibility to ampicillin should be performed. Therapy may be instituted prior to the results of susceptibility testing.

A history of a previous hypersensitivity reaction to any of the penicillins is a contraindication. Ampicillin is also contraindicated in infections caused by penicillinase-producing organisms.

SERIOUS AND OCCASIONAL FATAL HYPERSENSITIVITY (ANAPHYLACTOID) REACTIONS HAVE BEEN REPORTED IN PATIENTS ON PENICILLIN THERAPY. ALTHOUGH ANAPHYLAXIS IS MORE FREQUENT FOLLOWING PARENTERAL ADMINISTRATION, IT HAS OCCURRED IN PATIENTS ON ORAL PENICILLINS. THESE REACTIONS ARE MORE LIKELY TO OCCUR IN INDIVIDUALS WITH A HISTORY OF PENICILLIN HYPERSENSITIVITY AND/OR A HISTORY OF SENSITIVITY TO MULTIPLE ALLERGENS.

THERE HAVE BEEN REPORTS OF INDIVIDUALS WITH A HISTORY OF PENICILLIN HYPERSENSITIVITY WHO HAVE EXPERIENCED SEVERE HYPERSENSITIVITY REACTIONS WHEN TREATED WITH CEPHALOSPORINS. BEFORE INITIATING THERAPY WITH ANY PENICILLIN, CAREFUL INQUIRY SHOULD BE MADE CONCERNING PREVIOUS HYPERSENSITIVITY REACTIONS TO PENICILLINS, CEPHALOSPORINS, AND OTHER ALLERGENS. IF AN ALLERGIC REACTION OCCURS, THE DRUG SHOULD BE DISCONTINUED AND APPROPRIATE THERAPY INSTITUTED. SERIOUS ANAPHYLACTOID REACTIONS REQUIRE IMMEDIATE EMERGENCY TREATMENT WITH EPINEPHRINE. OXYGEN, INTRAVENOUS STEROIDS, AND AIRWAY MANAGEMENT, INCLUDING INTUBATION, SHOULD ALSO BE ADMINISTERED AS INDICATED.

Pseudomembranous colitis has been reported with nearly all antibacterial agents, including ampicillin, and may range in severity from mild to life-threatening. Therefore, it is important to consider this diagnosis in patients who present with diarrhea subsequent to the administration of antibacterial agents.

Treatment with antibacterial agents alters the normal flora of the colon and may permit overgrowth of clostridia. Studies indicate that a toxin produced by clostridium difficile, is one primary cause of “antibiotic-associated colitis”.

After the diagnosis of pseudomembranous colitis has been established, therapeutic measures should be initiated. Mild cases of pseudomembranous colitis usually respond to drug discontinuation alone. In moderate to severe cases, consideration should be given to management with fluids and electrolytes, protein supplementation and treatment with an antibacterial drug clinically effective against C. difficile colitis.

As with other penicillins, it may be expected that untoward reactions will be essentially limited to sensitivity phenomena. They are more likely to occur in individuals who have previously demonstrated hypersensitivity to penicillin and in those with a history of allergy, asthma, hay fever, or urticaria.

The following adverse reactions have been reported as associated with the use of ampicillin:

GASTROINTESTINAL: glossitis, stomatitis, nausea, vomiting, enterocolitis, pseudomembranous colitis, and diarrhea. These reactions are usually associated with oral dosage forms of the drugs.

HYPERSENSITIVITY REACTIONS: An erythematous, mildly pruritic, maculopapular skin rash has been reported fairly frequently . The rash, which usually does not develop within the first week of therapy, may cover the entire body including the soles, palms, and oral mucosa. The eruption usually disappears in three to seven days. Other hypersensitivity reactions that have been reported are: skin rash, pruritus, urticaria, erythema multiforme, and an occasional case of exfoliative dermatitis. Anaphylaxis is the most serious reaction experienced and has usually been associated with the parenteral dosage form of the drug.

NOTE: Urticaria, other skin rashes, and serum sicknesslike reactions may be controlled by 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 anaphylactoid reactions require emergency measures (see WARNINGS).

LIVER: Moderate elevation in serum glutamic oxaloacetic transaminase (SGOT) has been noted, but the significance of this finding is unknown.

HEMIC AND LYMPHATIC SYSTEMS: Anemia, thrombocytopenia, thrombocytopenic purpura, eosinophilia, leukopenia, and agranulocytosis have been reported during therapy with penicillins. These reactions are usually reversible on discontinuation of therapy and are believed to be hypersensitivity phenomena.

Other adverse reactions that have been reported with the use of ampicillin are laryngeal stridor and high fever. An occasional patient may complain of sore mouth or tongue as with any oral penicillin preparation.

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In case of overdosage, discontinue medication, treat symptomatically and institute supportive measures as required. In patients with renal function impairment, ampicillin-class antibiotics can be removed by hemodialysis but not by peritoneal dialysis.

ADULTS AND CHILDREN WEIGHING OVER 20 KG:

For genitourinary or gastrointestinal tract infections other than gonorrhea in men and women, the usual dose is 500 mg qid in equally spaced doses; severe or chronic infections may require larger doses. For the treatment of gonorrhea in both men and women, a single oral dose of 3.5 grams of ampicillin administered simultaneously with 1 gram of probenecid is recommended. Physicians are cautioned to use no less than the above recommended dosage for the treatment of gonorrhea. Follow-up cultures should be obtained from the original site(s) of infection 7 to 14 days after therapy. In women, it is also desirable to obtain culture test-of-cure from both the endocervical and anal canals. Prolonged intensive therapy is needed for complications such as prostatitis and epididymitis.

For respiratory tract infections, the usual dose is 250 mg qid in equally spaced doses.

CHILDREN WEIGHING 20 KG OR LESS:

For genitourinary or gastrointestinal tract infections, the usual dose is 100 mg/kg/day total, qid in equally divided and spaced doses. For respiratory infections, the usual dose is 50 mg/kg/day total, in equally divided and spaced doses three to four times daily. Doses for children should not exceed doses recommended for adults.

ALL PATIENTS, IRRESPECTIVE OF AGE AND WEIGHT:

Larger doses may be required for severe or chronic infections. Although ampicillin is resistant to degradation by gastric acid, it should be administered at least one-half hour before or two hours after meals for maximal absorption. Except for the single dose regimen for gonorrhea referred to above, therapy should be continued for a minimum of 48 to 72 hours after the patient becomes asymptomatic or evidence of bacterial eradication has been obtained. In infections caused by hemolytic strains of streptococci, a minimum of 10 days’ treatment is recommended to guard against the risk of rheumatic fever of glomerulonephritis (see PRECAUTIONS–Laboratory Tests). In the treatment of chronic urinary or gastrointestinal infections, frequent bacteriologic and clinical appraisal is necessary during therapy and may be necessary for several months afterwards. Stubborn infections may require treatment for several weeks. Smaller doses than those indicated above should not be used.

Ampicillin Capsules, USP: Each capsule, for oral administration, contains ampicillin trihydrate equivalent to 250 mg or 500 mg ampicillin, and are supplied as:

500 mg: white, opaque, hard gelatin capsules, imprinted in black ink GG 851/GG 851.

NDC 54868-3113-1 in bottles of 14

NDC 54868-3113-5 in bottles of 30

Ampicillin

Capsules, USP

500 mg

Rx only