ampicillin : Complexes, Storage & Clinical Research on Healthline.com

Possible emergence and overgrowth of nonsusceptible bacteria or fungi. Discontinue and institute appropriate therapy if superinfection occurs.

Treatment with anti-infectives may permit overgrowth of clostridia. Consider Clostridium difficile-associated diarrhea and colitis (antibiotic-associated pseudomembranous colitis) if diarrhea develops and manage accordingly.

Some mild cases of C. difficile-associated diarrhea and colitis may respond to discontinuance alone. Manage moderate to severe cases with fluid, electrolyte, and protein supplementation; appropriate anti-infective therapy (e.g., oral metronidazole or vancomycin) recommended if colitis is severe.

Sensitivity Reactions

Hypersensitivity Reactions

Serious and occasionally fatal hypersensitivity reactions, including anaphylaxis, reported with penicillins.

Prior to initiation of therapy, make careful inquiry regarding previous hypersensitivity reactions to penicillins, cephalosporins, or other drugs. Partial cross-allergenicity occurs among penicillins and other β-lactam antibiotics including cephalosporins and cephamycins.

If a severe hypersensitivity reaction occurs, discontinue immediately and institute appropriate therapy as indicated (e.g., epinephrine, corticosteroids, maintenance of an adequate airway and oxygen).

General Precautions

Selection and Use of Anti-infectives

To reduce development of drug-resistant bacteria and maintain effectiveness of ampicillin and other antibacterials, use only for treatment or prevention of infections proven or strongly suspected to be caused by susceptible bacteria.

When selecting or modifying anti-infective therapy, use results of culture and in vitro susceptibility testing. In the absence of such data, consider local epidemiology and susceptibility patterns when selecting anti-infectives for empiric therapy.

Mononucleosis

Possible increased risk of rash in patients with mononucleosis; use in these patients not recommended.

Ampicillin-resistant Haemophilus influenzae

Because of increasing prevalence of ampicillin-resistant H. influenzae, the drug should not be used alone for empiric treatment of serious infections (e.g., meningitis, pneumonia) when H. influenzae may be involved.

Laboratory Monitoring

Periodically assess organ system functions, including renal, hepatic, and hematopoietic, during prolonged therapy.

Sodium Content

Specific Populations

Pregnancy

Lactation

Pediatric Use

Renal clearance of ampicillin may be delayed in neonates and young infants because of incompletely developed renal function. Use lowest effective dosage.

Renal Impairment

Dosage adjustments necessary in renal impairment. (See Renal Impairment under Dosage and Administration.)

Common Adverse Effects

Drug Interactions

Specific Drugs and Laboratory Tests

Drug or Test	Interaction	Comments
Allopurinol	Possible increased incidence of rash	Unclear whether potentiation of rash is caused by allopurinol or hyperuricemia present in these patients Clinical importance has not been determined; some clinicians suggest that concomitant use of the drugs should be avoided if possible
Aminoglycosides	In vitro evidence of synergistic antibacterial effects against enterococci; used to therapeutic advantage in treatment of endocarditis and other severe enterococcal infections Potential in vitro and in vivo inactivation of aminoglycosides
Chloramphenicol	In vitro evidence of antagonism	Clinical importance unclear
Hormonal contraceptives	Possible decreased efficacy of estrogen-containing oral contraceptives and increased incidence of breakthrough bleeding	Some clinicians suggest that a supplemental method of contraception be used in patients receiving oral contraceptives and ampicillin concomitantly, other clinicians state that most women taking oral contraceptives probably do not need to use alternative contraceptive precautions while receiving ampicillin
Methotrexate	Possible decreased renal clearance of methotrexate with penicillins; possible increased methotrexate concentrations and hematologic and GI toxicity	Monitor closely if used concomitantly
Probenecid	Decreased renal tubular secretion of ampicillin; increased and prolonged ampicillin concentrations may occur
Sulbactam	Synergistic bactericidal effect against many strains of β-lactamase-producing bacteria
Sulfonamides	In vitro evidence of antagonism	Clinical importance unclear
Tests for glucose	Possible false-positive reactions in urine glucose tests using Clinitest^®, Benedict’s solution, or Fehling’s solution	Use glucose tests based on enzymatic glucose oxidase reactions (e.g., Clinistix^®, Tes-Tape^®)
Tests for uric acid	Possible falsely increased serum uric acid concentrations when copper-chelate method is used; phosphotungstate and uricase methods appear to be unaffected by the ampicillin

Ampicillin
WC 404 500 mg	AMP / 500 500 mg	AMP / 250 250 mg	WC 402 250 mg
Principen
BRISTOL 7992 / BRISTOL 7992 250 mg	BRISTOL 7993 / BRISTOL 7993 500 mg

Drug Notebook

Generic Name: ampicillin

Cautions

Contraindications

Warnings/Precautions

Warnings

Superinfection/Clostridium difficile-associated Colitis