- Generic Name: ampicillin
- Dosage Forms: n.a.
- Other Brand Names: Principen, Omnipen-N, Totacillin-N, Ampicillin
What is Ampicillin Trihydrate?
Treatment of enterococcal endocarditis; used in conjunction with an aminoglycoside.
Treatment of endocarditis caused by slow-growing fastidious gram-negative bacilli termed the HACEK group (i.e., Haemophilus parainfluenzae, H. aphrophilus, Actinobacillus actinomycetemcomitans, Cardiobacterium hominis, Eikenella corrodens, Kingella kingae). Used in conjunction with gentamicin; consider that these infections may involve β-lactamase-producing bacteria resistant to ampicillin alone.
Treatment of endocarditis caused by susceptible staphylococci, streptococci, E. coli, P. mirabilis, or Salmonella.
Prevention of α-hemolytic (viridans group) streptococcal bacterial endocarditis in patients undergoing certain dental procedures (i.e., procedures that involve manipulation of gingival tissue or periapical region of teeth or perforation of oral mucosa) or certain invasive respiratory tract procedures (i.e., procedures involving incision or biopsy of respiratory mucosa) who have certain cardiac conditions that put them at highest risk of adverse outcomes from endocarditis. AHA recommends oral amoxicillin as drug of choice; ampicillin is an alternative in those unable to take oral medication.
Anti-infective prophylaxis solely for prevention of bacterial endocarditis no longer recommended by AHA for patients undergoing GI or GU procedures.
Consult most recent AHA recommendations for information on which cardiac conditions are associated with highest risk of adverse outcomes from endocarditis and specific recommendations regarding use of prophylaxis to prevent endocarditis in these patients.
Meningitis and Other CNS Infections
Treatment of meningitis caused by susceptible Neisseria meningitidis, Streptococcus agalactiae (group B streptococci; GBS), Listeria monocytogenes, E. coli, H. influenzae, or S. pneumoniae.
Drug of choice for empiric treatment of neonatal S. agalactiae meningitis. An aminoglycoside (IV gentamicin) used concomitantly until in vitro susceptibility testing is complete and a clinical response obtained; treatment can then be changed to penicillin G.
Drug of choice for L. monocytogenes meningitis; used alone or in conjunction with an aminoglycoside (e.g., gentamicin).
Penicillin G usually preferred for N. meningitidis meningitis and penicillin-susceptible S. pneumoniae meningitis. For H. influenzae meningitis, cefotaxime, ceftriaxone, or, alternatively, ampicillin in conjunction with chloramphenicol is recommended; ampicillin should not be used alone (see Ampicillin-resistant Haemophilus influenzae under Cautions).
Respiratory Tract Infections
Treatment of respiratory tract infections caused by susceptible Staphylococcus aureus (including penicillinase-producing strains), Streptococcus (including S. pneumoniae), S. pyogenes (group A β-hemolytic streptococci), or H. influenzae (nonpenicillinase-producing strains only).
Generally should not be used for the treatment of streptococcal or staphylococcal infections when a natural penicillin would be effective. Should not be used alone for empiric treatment of respiratory tract infections when ampicillin-resistant H. influenzae may be involved.
Septicemia
Treatment of septicemia caused by susceptible staphylococci, streptococci, enterococci, E. coli, P. mirabilis, or Salmonella.
Urinary Tract Infections (UTIs)
Treatment of UTIs caused by susceptible enterococci, E. coli, or Proteus mirabilis.
A drug of choice for enterococcal UTIs. Because of high urinary concentrations, may be effective when used alone, but consider that enterococci resistant to ampicillin have been reported.
Eikenella Infections
Treatment of infections caused by Eikenella corrodens; drug of choice.
Gonorrhea and Associated Infections
Previously used for treatment of acute uncomplicated gonorrhea (anogenital and urethral) caused by susceptible Neisseria gonorrhoeae. Has been used for gonococcal urethritis. No longer recommended for gonorrhea or gonococcal urethritis by CDC or others (high incidence of penicillin-resistant N. gonorrhoeae).
Listeria Infections
Treatment of infections caused by Listeria monocytogenes; used alone or in conjunction with an aminoglycoside.
A drug of choice for Listeria infections occurring during pregnancy, granulomatosis infantiseptica, sepsis, endocarditis, meningitis, and foodborne infections. (See Meningitis and Other CNS Infections under Uses.)
Pertussis
Has been used to treat and prevent secondary pulmonary infections in patients with pertussis. Erythromycin generally considered drug of choice for treatment of catarrhal stage of pertussis and to shorten the period of communicability of the disease. Ampicillin, like most other anti-infectives, does not shorten clinical course of pertussis.
Typhoid Fever and Other Salmonella Infections
Alternative for treatment of typhoid fever (enteric fever) caused by susceptible Salmonella typhi. Drugs of choice are third generation cephalosporins (e.g., ceftriaxone, cefotaxime) or fluoroquinolones (e.g., ciprofloxacin, ofloxacin); consider that multidrug-resistant strains of S. typhi (strains resistant to ampicillin, amoxicillin, chloramphenicol, and/or co-trimoxazole) reported with increasing frequency.
Treatment of chronic carriers of S. typhi; drugs of choice are fluoroquinolones (e.g., ciprofloxacin), ampicillin, or amoxicillin (with probenecid).
Treatment of gastroenteritis caused by susceptible Salmonella.
Shigella Infections
Treatment of GI infections caused by susceptible Shigella.
Anti-infectives generally indicated in addition to fluid and electrolyte replacement for severe shigellosis. Previously considered a drug of choice for shigellosis (especially in children), but strains of S. flexneri and S. sonnei resistant to ampicillin reported with increasing frequency. Fluoroquinolones, ceftriaxone, or co-trimoxazole now considered drugs of choice for empiric treatment, especially in areas where ampicillin-resistant strains of Shigella have been reported.
Prevention of Perinatal Group B Streptococcal Disease
Prevention of early-onset neonatal group B streptococcal (GBS) disease.
Intrapartum anti-infective prophylaxis to prevent early-onset neonatal GBS disease is indicated in women identified as GBS carriers during routine prenatal GBS screening performed at 35–37 weeks during the current pregnancy, in women with GBS bacteriuria identified at any time during current pregnancy, and in women who had a previous infant diagnosed with invasive GBS disease. In those with unknown GBS status at onset of labor, intrapartum anti-infective prophylaxis indicated if delivery is at <37 weeks' gestation, duration of amniotic membrane rupture is ≥18 hours, or intrapartum temperature is ≥38°C.
When intrapartum GBS prophylaxis indicated in the mother for prevention of GBS in the neonate, initiate at onset of labor or rupture of membranes. If cesarean delivery performed before onset of labor in a woman with intact amniotic membranes, anti-infective prophylaxis not usually indicated regardless of GBS colonization status of the woman or gestational age.
IV penicillin G is drug of choice and IV ampicillin is preferred alternative. Penicillin G has a narrower spectrum of activity and is less likely to select for antibiotic-resistant organisms.
Regardless of whether the mother received anti-infective prophylaxis, initiate appropriate diagnostic evaluations and anti-infective therapy in the neonate if signs or symptoms of active infection develop.
Consult most recent CDC and AAP guidelines for additional information on prevention of perinatal GBS disease.