Action And Clinical Pharmacology: Ampicillin is a broad-spectrum penicillin, indicated for the treatment of a wide range of bacterial infections caused by ampicillin-sensitive organisms.
Ampicillin is similar to benzyl penicillin in its bactericidal action against susceptible organisms during the stage of active multiplication. It acts through the inhibition of cell wall mucopeptide biosynthesis. Ampicillin has a broad spectrum of bactericidal activity against many gram-positive and gram-negative aerobic and anaerobic bacteria. (Ampicillin is, however, degraded by beta-lactamases and therefore the spectrum of activity does not normally include organisms which produce these enzymes.)
Ampicillin diffuses readily into most body tissue and fluids. However, penetration into the cerebrospinal fluid and brain occurs only when the meninges are inflamed. Ampicillin is excreted largely unchanged in the urine and its excretion can be delayed by concurrent administration of probenecid. The active form appears in the bile in higher concentrations than those found in the serum. Ampicillin is the least serum-bound of all the penicillins, averaging about 20% compared to approximately 60 to 90% for other penicillins.
Most strains of the following organisms have been shown in in vitro studies to be susceptible to ampicillin: gram-positive organisms: hemolytic and nonhemolytic streptococci, S. pneumoniae, nonpenicillinase-producing staphylococci, Clostridia sp., B. anthracis, Listeria monocytogenes, C. xerosis and most strains of enterococci; gram-negative organisms: H. influenzae, B. funduliformis, N. Gonorrhea, N. meningitides, Br. abortus, Br. melitensis, Proteus mirabilis and many strains of Salmonella, Shigella and E. coli.
Indications And Clinical Uses: Ampicillin is indicated in the treatment of respiratory tract infections, urinary tract infections, gonorrhea, gastrointestinal infections and bacterial meningitis, septicemia and endocarditis caused by susceptible organisms such as: Gram-positive Bacteria: S. aureus (nonpenicillinase- producing), S. epidermidis (nonpenicillinase-producing), S. saprophyticus (nonpenicillinase-producing), Enterobacter faecalis, S. pneumoniae, S. pyogenes and S. viridans.
Gram-negative Bacteria: H. influenzae (nonpenicillinase- producing), B. catarrhalis (nonpenicillinase-producing), E. coli (nonpenicillinase-producing), P. mirabilis (nonpenicillinase-producing), P. vulgaris, Providencia rettgeri, Providencia stuartii, M. morganii, and N. gonorrhea (nonpenicillinase- producing), Shigellae, S. typhosa and other Salmonellae.
Anerobes: Clostridium species, Peptococcus species, Peptostreptococcus species, Bacteroides species, including B. fragilis.
Bacteriology studies to determine the causative organisms and their susceptibility to ampicillin should be performed. Therapy may be instituted prior to obtaining results of susceptibility testing.
Contra-Indications: Ampicillin is contraindicated in patients with a history of hypersensitivity to any penicillin or cephalosporin.
Manufacturers’ Warnings In Clinical States: Serious and occasional fatal hypersensitivity (anaphylaxis) reactions have been reported in patients on penicillin therapy especially following parenteral administration. These reactions are more apt to occur in individuals with a history of sensitivity to multiple allergens.
There have been well-documented reports of individuals with a history of penicillin hypersensitivity reactions who have experienced severe hypersensitivity reactions when treated with a cephalosporin. Before therapy with a 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 the patient treated with the usual agents (e.g., pressor amines, antihistamines, and corticosteroids). Serious anaphylactoid reactions are not controlled by antihistamines alone, and require such emergency measures as the immediate use of epinephrine, aminophylline, oxygen, and i.v. corticosteroids.
Precautions: General: A high percentage of patients with infectious mononucleosis or lymphatic leukemia who receive ampicillin develop a skin rash, and the drug should not be administered to such patients. In most cases, the rash is maculopapular, pruritic, and generalized.
Prolonged use of antibiotics may promote overgrowth of nonsusceptible organisms. Should superinfections occur, appropriate measures should be taken.
Drug Interactions: The concurrent administration of allopurinol and ampicillin increases substantially the incidence of 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 to hyperuricemia present in these patients. Ampicillin and aminoglycosides should not be reconstituted together due to the in vitro inactivation of the aminoglycosides by the ampicillin.
Drug/Laboratory Test Interactions : Following administration of ampicillin to pregnant women, a transient decrease in plasma concentration of total conjugated estriol, estriol-glucuronide, conjugated estrone and estradiol has been noted.
With high urine concentrations of ampicillin, false-positive urinary glucose reactions may occur if copper reduction methods are used. Therefore, it is recommended that glucose tests based on enzymatic glucose oxidase reactions be employed.
Pregnancy: Animal studies with ampicillin have shown no teratogenic effects. 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: It is not known whether use of ampicillin-class antibiotics 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.
Lactation: Ampicillin is excreted in trace amounts in human milk. Therefore caution should be exercised when ampicillin is administered to a nursing mother.
Geriatrics: There are no known specific precautions for the use of ampicillin in the elderly.
Adverse Reactions: As with other penicillins, presumably, the most common untoward reactions will be related to sensitivity phenomena. Hypersensitivity reactions are more likely to occur in individuals who have previously demonstrated hypersensitivity to penicillins and in those with a history of allergy, asthma, hay fever or urticaria. The following adverse reactions have been reported with the use of ampicillin.
Gastrointestinal: glossitis, stomatitis, black “hairy” tongue, nausea, vomiting, enterocolitis and diarrhea. Severe pseudomembranous colitis has been reported in some patients.
Hypersensitivity: Skin rashes and urticaria have been reported frequently. A few cases of exfoliative dermatitis and erythema multiforme have been reported. Anaphylaxis is the most serious reaction experienced and has usually been associated with the parenteral dosage forms.
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 is life-threatening and amenable only to ampicillin therapy.
Liver: A moderate rise in AST has been noted, but the significance of this finding is unknown. Mild transitory AST elevations have been observed in individuals receiving larger (2 to 4 times) than usual and oft-repeated i.m. injections. Evidence indicates that AST is released at the site of the i.m. injection of ampicillin sodium, and the presence of increased amounts of this enzyme in the blood does not necessarily indicate liver involvement.
Hematologic: Anemia, thrombocytopenia, thrombocytopenic purpura, hemorrhagic diathesis, eosinophilia, leukopenia and agranulocytosis have been reported rarely in association with ampicillin therapy. These reactions are usually reversible on discontinuation of therapy and are believed to be hypersensitivity phenomena.
Renal: Interstitial nephritis has been reported.
Ototoxicity: Ampicillin may be ototoxic when given i.v. in very high doses.
Symptoms And Treatment Of Overdose: Symptoms and Treatment: The treatment of overdosage would likely be needed only in patients with severely impaired renal function, since patients with normal kidneys excrete penicillins at a rapid rate (90% unchanged, normal renal excretion, with half-life of 1.5 hours).
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.
Dosage And Administration: Ear, Nose, Throat and Lower Respiratory Tract Infections: Adults and children 40 kg or over: 250 to 500 mg every 6 hours. Children under 40 kg: 25 to 50 mg/kg/day in equally divided doses at 6- to 8-hour intervals.
Gastrointestinal and Genitourinary Tract Infections (including genitourinary infections caused by N. gonorrhea in females): Adults and children 40 kg or over: 500 mg every 6 hours. Children under 40 kg: 50 mg/kg/day in equally divided doses at 6- to 8-hour intervals.
The children’s dosage is intended for individuals whose weights will not cause a dosage to be calculated greater than that recommended for adults.
In the treatment of chronic urinary tract and intestinal infections, frequent bacteriological and clinical appraisal is necessary. Smaller doses than those recommended above should not be used. Higher doses should be used for stubborn or severe infections. In stubborn infections, therapy may be required for several weeks. It may be necessary to continue clinical and/or bacteriological follow up for several months after cessation of therapy.
Urethritis in males due to N. gonorrhea: Adults: 2 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 4 months.
The parenteral doses for the preceding infections may be given by either the i.m. or i.v. route. A change to oral ampicillin may be made when appropriate.
Bacterial Meningitis: Adults and children with bacterial meningitis (caused by N. meningitides or H. influenzae) have been sucessfully treated with doses of 150 to 200 mg/kg/day in divided doses every 3 or 4 hours. A few adults have been successfully treated for bacterial meningitis with doses ranging from 8 to 14 g daily. This treatment has been initiated with i.v. drip therapy and continued with frequent (every 3 to 4 hours) i.m. therapy.
Septicemia: Adult and children: 150 to 200 mg/kg/day in equally divided doses every 3 to 4 hours. Start with i.v. administration for at least 3 days, and continue with either the i.v. or i.m. route.
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.
Reconstitution: Use only freshly prepared solutions. I.M. and I.V. injections should be administered within 1 hour after preparation, since the potency may decrease significantly after this period.
Direct I.V. Use: Use Sterile Water for Injection, USP. Add 5 mL to the 125, 250 or 500 mg vial, withdraw contents, and administer slowly over a period of 3 to 5 minutes. Add 10 mL to the 1 g vial and withdraw the entire contents. Inject slowly over a period of at least 10 to 15 minutes. Caution: More rapid administration may result in convulsive seizures.
I.V. Infusion: Reconstitute the 1 or 2 g vial with 10 mL of Sterile Water for Injection, USP prior to dilution with the i.v. solution. Stability studies on ampicillin sodium, at concentrations of 2 mg/mL and 30 mg/mL in various i.v. solutions, indicate the drug will lose less than 10% activity at room temperature (15 to 30°C) for the time periods stated.
Only those solutions listed above should be used for the i.v. infusion of ampicillin. 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.
Availability And Storage: Each dry filled vial contains: ampicillin 125 mg, 250 mg, 500 mg, 1 g and 2 g (as the sodium salt). Nonmedicinal ingredients: none. Sodium: 2.9 mEq/g.
AMPICIN® Bristol Ampicillin Sodium Antibiotic