Medically reviewed on March 25, 2018
(am pi SIL in)
- Ampicillin Sodium
- Ampicillin Trihydrate
Excipient information presented when available (limited, particularly for generics); consult specific product labeling. [DSC] = Discontinued product
Generic: 250 mg [DSC], 500 mg
Solution Reconstituted, Injection, as sodium [strength expressed as base]:
Generic: 125 mg (1 ea); 250 mg (1 ea); 500 mg (1 ea); 1 g (1 ea); 2 g (1 ea); 10 g (1 ea)
Solution Reconstituted, Injection, as sodium [strength expressed as base, preservative free]:
Generic: 250 mg (1 ea); 500 mg (1 ea)
Solution Reconstituted, Intravenous, as sodium [strength expressed as base]:
Generic: 1 g (1 ea); 2 g (1 ea); 10 g (1 ea)
Solution Reconstituted, Intravenous, as sodium [strength expressed as base, preservative free]:
Generic: 10 g (1 ea [DSC])
Suspension Reconstituted, Oral:
Generic: 125 mg/5 mL (100 mL [DSC], 200 mL [DSC]); 250 mg/5 mL (100 mL [DSC], 200 mL [DSC])
- Antibiotic, Penicillin
Inhibits bacterial cell wall synthesis by binding to one or more of the penicillin-binding proteins (PBPs) which in turn inhibits the final transpeptidation step of peptidoglycan synthesis in bacterial cell walls, thus inhibiting cell wall biosynthesis. Bacteria eventually lyse due to ongoing activity of cell wall autolytic enzymes (autolysins and murein hydrolases) while cell wall assembly is arrested.
Into bile; penetration into CSF occurs with inflamed meninges only
Urine (∼90%, unchanged within 24 hours); feces
Time to Peak
Serum concentration: Oral: Within 1 to 2 hours
PNA 2 to 7 days: 4 hours
PNA 8 to 14 days: 2.8 hours
PNA 15 to 30 days: 1.7 hours
Children and Adults: 1 to 1.8 hours (Bergan 1978)
Anuric patients: 8 to 20 hours
Neonates: 10%; Adults: 15% to 18%
Use: Labeled Indications
Genitourinary tract infections: Treatment of genitourinary tract infections caused by Escherichia coli, Proteus mirabilis, enterococci, Shigella, Salmonella typhosa and other Salmonella, and nonpenicillinase-producing N. gonorrhoeae. Note: Ampicillin is not recommended by the CDC as a first-line agent in the treatment of gonorrhea (CDC, 2010).
GI tract infections: Treatment of GI tract infections caused by Shigella, S. typhosa and other Salmonella, E. coli, P. mirabilis, and enterococci. Note: Ampicillin is not recommended as a first-line agent for Shigellosis, Salmonellosis (nontyphoid), or Salmonella enterica species (typhoid fever) due to development of resistance (CDC, 2014).
Respiratory tract infections: Treatment of respiratory tract infections caused by nonpenicillinase-producing H. influenzae and staphylococci, and streptococci, including Streptococcus pneumoniae.
Bacterial meningitis: Treatment of bacterial meningitis caused by E. coli, group B streptococci, and other gram-negative bacteria (N. meningitidis).
Gastrointestinal infections: Treatment of GI infections caused by S. typhi (typhoid fever), other Salmonella species and Shigella species (dysentery). Note: Ampicillin is not recommended as a first-line agent for Shigellosis, Salmonellosis (nontyphoid), or S. enterica species (typhoid fever) due to development of resistance (CDC, 2014).
Respiratory tract infections: Treatment of respiratory tract infections caused by S. pneumoniae, Staphylococcus aureus (penicillinase and nonpenicillinase producing), H. influenzae, and group A beta-hemolytic streptococci.
Septicemia and endocarditis: Treatment of septicemia and endocarditis caused by susceptible gram-positive organisms, including Streptococcus species, penicillin G-susceptible staphylococci, and enterococci; gram-negative sepsis caused by E. coli, P. mirabilis, and Salmonella species.
Urinary tract infections: Treatment of urinary tract infections caused by E. coli and P. mirabilis.
Off Label Uses
Community-acquired pneumonia (children)
Following clinical guideline recommendations on the management of CAP reduces the incidence of morbidity and mortality related to pneumonia. Ampicillin is the preferred parenteral option for empirical treatment of suspected bacterial CAP in areas where local penicillin resistance in pneumococcal strains is low, and for pathogen-directed therapy aimed at S. pneumoniae, GAS, or beta-lactamase-negative H. influenzae in children older than 3 months of age. In regions where high-level penicillin resistance among invasive strains is substantial, high-dose ampicillin is recommended.
Based on the American Heart Association (AHA) guidelines for the prevention of infective endocarditis, ampicillin is effective and recommended for administration to patients with certain cardiac conditions who are unable to take oral medication to provide prophylaxis against infective endocarditis associated with dental or respiratory tract procedures.
Endocarditis, treatment (HACEK organisms) (adults)
Based on the American Heart Association (AHA) Scientific Statement for Infective Endocarditis in Adults, ampicillin is an effective and recommended treatment option for infective endocarditis (native or prosthetic valve) due to HACEK organisms (Haemophilus spp., Aggregatibacter spp., Cardiobacterium hominis, Eikenella corrodens, and Kingella spp.) if the growth of the isolate is sufficient to permit in vitro susceptibility results.
Osteomyelitis, native vertebral
Based on the Infectious Diseases Society of America (IDSA) guidelines for the diagnosis and treatment of native vertebral osteomyelitis in adults, ampicillin is an effective and recommended agent for the treatment of native vertebral osteomyelitis due to penicillin-susceptible Enterococcusspecies.
Prophylaxis in patients with prosthetic joint implants undergoing dental procedures which produce bacteremia
Although currently not recommended for routine use prior to dental procedures in patients with prosthetic joint implants to prevent prosthetic joint infection as stated within the American Academy of Orthopaedic Surgeons/American Dental Association Prevention of Orthopaedic Implant Infection in Patients Undergoing Dental Procedures guidelines and a subsequent report of the American Dental Association Council on Scientific Affairs, if deemed to be necessary for select patients at risk for prosthetic joint infection (eg, history of complications associated with joint replacement surgery), antibiotic prophylaxis may be considered. Dentists planning invasive oral procedures should therefore consult with the patient's orthopedic surgeon to determine the risk associated with infection and the need for antibiotics. Based on a retired advisory statement from the American Dental Association and American Academy of Orthopaedic Surgeons, the use of ampicillin (or cefazolin) was suggested for patients not allergic to penicillin and unable to take oral medications [ADA/AAOS 2003].
Prosthetic joint infection
Based on the Infectious Diseases Society of America (IDSA) guidelines for the management of prosthetic joint infection, ampicillin is an effective and recommended agent for the treatment of prosthetic joint infection with Enterococcus spp. (penicillin-susceptible).
Surgical prophylaxis (liver transplantation)
Based on the American Society of Health-System Pharmacists (ASHP), the Infectious Diseases Society of America (IDSA), the Surgical Infection Society (SIS), and the Society of Healthcare Epidemiology of America (SHEA) guidelines for antimicrobial prophylaxis in surgery, ampicillin is an effective and recommended agent (in combination with piperacillin-tazobactam and cefotaxime) for perioperative surgical prophylaxis in patients undergoing liver transplantation.
Additional Off-Label Uses
Group B streptococcus (maternal dose for neonatal prophylaxis); Urinary tract infection due to ampicillin-susceptible Enterococcus spp.
Hypersensitivity (eg, anaphylaxis) to ampicillin, any component of the formulation, or other penicillins; infections caused by penicillinase-producing organisms
Usual dosage range:
Oral: 250 to 500 mg every 6 hours
IM, IV: 1 to 2 g every 4 to 6 hours or 50 to 250 mg/kg/day in divided doses (maximum: 12 g/day)
Endocarditis, treatment (off-label dose; AHA [Baddour 2015]): IV:
Enterococcus, native or prosthetic valve (penicillin/gentamicin-susceptible strains): 2 g every 4 hours with concomitant ceftriaxone for 6 weeks or 2 g every 4 hours with concomitant gentamicin for 4 to 6 weeks (4 weeks for native valve and symptoms present <3 months; 6 weeks for native valve and symptoms present ≥3 months or for prosthetic valve)
Enterococcus, native or prosthetic valve (penicillin-susceptible/aminoglycoside-resistant strains): 2 g every 4 hours with concomitant ceftriaxone for 6 weeks
Enterococcus, native or prosthetic valve (penicillin-susceptible/gentamicin-resistant/streptomycin-susceptible strains): 2 g every 4 hours with concomitant streptomycin for 4 to 6 weeks (4 weeks for native valve and symptoms present <3 months; ≥6 weeks for native valve and symptoms present ≥3 months or prosthetic valve).
HACEK organisms, native or prosthetic valve (off-label use): 2 g every 4 hours for 4 weeks (native valve) or 6 weeks (prosthetic valve).
Viridans group streptococcus (VGS) and S. bovis:
Native valve: Highly penicillin-susceptible (MIC ≤0.12 mcg/mL): 2 g every 4 hours for 4 weeks (monotherapy) or for 2 weeks with concomitant gentamicin
Native valve: Relatively penicillin-resistant (MIC >0.12 to <0.5 mcg/mL): 2 g every 4 hours for 4 weeks with concomitant gentamicin for the first 2 weeks
Prosthetic valve: Highly penicillin-susceptible (MIC ≤0.12 mcg/mL): 2 g every 4 hours for 6 weeks (with or without concomitant gentamicin for the first 2 weeks)
Prosthetic valve: Relatively or fully penicillin-resistant (MIC >0.12 mcg/mL): 2 g every 4 hours with concomitant gentamicin for 6 weeks
Endocarditis, prophylaxis (off-label use):
Dental, oral, or respiratory tract procedures: IM, IV: 2 g within 30 to 60 minutes prior to procedure in patients not allergic to penicillin and unable to take oral amoxicillin. IM injections should be avoided in patients who are receiving anticoagulant therapy. In these circumstances, orally administered regimens should be given whenever possible. Intravenously administered antibiotics should be used for patients who are unable to tolerate or absorb oral medications. Note: American Heart Association (AHA) guidelines now recommend prophylaxis only in patients undergoing invasive procedures and in whom underlying cardiac conditions may predispose to a higher risk of adverse outcomes should infection occur (Wilson 2007).
Genitourinary and gastrointestinal tract procedures: IM, IV: Note: Routine prophylaxis for GI/GU procedures is no longer recommended by the AHA. Consider only in patients with the highest risk of adverse outcome from endocarditis (eg, prosthetic heart valve, previous endocarditis, some categories of congenital heart disease, cardiac valvulopathy in cardiac transplant patients) who have an established GI or GU enterococcal infection or for those already receiving antibiotic therapy to prevent a wound infection or sepsis associated with a GI or GU procedure in which enterococcal coverage is desired (Wilson 2007).
High-risk patients: 2 g within 30 minutes prior to procedure, followed by ampicillin 1 g (or amoxicillin 1 g orally) 6 hours later; must be used in combination with gentamicin (Dajani 1997).
Moderate-risk patients: 2 g within 30 minutes prior to procedure (Dajani 1997).
Genitourinary or gastrointestinal infections: Oral, IM, IV: 500 mg every 6 hours
Group B streptococcus (maternal dose for neonatal prophylaxis) (off-label use): IV: 2 g initial dose, then 1 g every 4 hours until delivery (CDC 2010)
Listeria infections (off-label dosing; Lorber, 1997): IV:
Bacteremia: 200 mg/kg/day divided every 6 hours for ≥2 weeks
Brain abscess or rhombencephalitis: 200 mg/kg/day divided every 4 hours with concomitant aminoglycoside for ≥6 weeks
Endocarditis: 200 mg/kg/day divided every 6 hours with concomitant aminoglycoside for ≥4 to 6 weeks
Meningitis: 200 mg/kg/day divided every 4 hours with concomitant aminoglycoside for ≥3 weeks
Mild to moderate infections: Oral: 250 to 500 mg every 6 hours
Osteomyelitis, native vertebral (off-label use): Enterococcus spp (penicillin-susceptible): IV: 12 g continuous infusion every 24 hours or 2 g every 4 hours for 6 weeks; the addition of an aminoglycoside for 4 to 6 weeks is recommended in patients with infective endocarditis (IDSA [Berbari 2015])
Prosthetic joint infection, Enterococcus spp (penicillin-susceptible) (off-label use): IV: 12 g continuous infusion every 24 hours or 2 g every 4 hours for 4 to 6 weeks; consider addition of aminoglycoside (Osmon, 2013).
Prophylaxis in total joint replacement patients undergoing dental procedures which produce bacteremia (off-label use): Note: In general, patients with prosthetic joint implants do not require prophylactic antibiotics prior to dental procedures. In planning an invasive oral procedure, dental consultation with the patient's orthopedic surgeon may be advised to review the risks of infection (Sollecito 2015).
IM, IV: 2 g 1 hour prior to procedure (ADA/AAOS 2003).
Respiratory tract infections:
Oral: 250 mg 4 times daily
IM, IV: 250 to 500 mg every 6 hours
Sepsis/meningitis: IM, IV: Note: administer doses IV initially; IM may be used later in therapy course: 150 to 200 mg/kg/day divided every 3 to 4 hours (range: 6 to 12 g/day)
Surgical (perioperative) prophylaxis in liver transplantation (off-label use): IV: 2 g within 60 minutes prior to surgery in combination with cefotaxime. Doses may be repeated in 2 hours if procedure is lengthy or if there is excessive blood loss (Bratzler, 2013).
Urinary tract infections (ampicillin-susceptible Enterococcus; off-label use): IV: 1 to 2 g every 4 to 6 hours with or without an aminoglycoside (Heintz 2010)
Refer to adult dosing.
Usual dosage range: Infants, Children, and Adolescents:
Oral: 50 to 100 mg/kg/day divided every 6 hours (maximum: 2 to 4 g/day)
IM, IV: 25 to 200 mg/kg/day divided every 3 to 4 hours (maximum: 12 g/day)
Community-acquired pneumonia (CAP) (IDSA/PIDS 2011): Infants >3 months, Children, and Adolescents: IV: Note: May consider addition of vancomycin or clindamycin to empiric therapy if community-acquired MRSA suspected. In children ≥5 years, a macrolide antibiotic should be added if atypical pneumonia cannot be ruled out. Maximum daily dose of ampicillin: 12 g/day (Red Book [AAP 2012]).
Empiric treatment or S. pneumoniae (moderate to severe; MICs to penicillin ≤2.0 mcg/mL) or H. influenzae (beta-lactamase negative) (preferred): 150 to 200 mg/kg/day divided every 6 hours
Group A Streptococcus (moderate to severe) (preferred): 200 mg/kg/day divided every 6 hours
S. pneumoniae (moderate to severe; MICs to penicillin ≥4.0 mcg/mL) (alternative to ceftriaxone): 300 to 400 mg/kg/day divided every 6 hours
Endocarditis, prophylaxis (off-label use): Note: AHA guidelines (Baltimore 2015) limit the use of prophylactic antibiotics to patients at the highest risk for infective endocarditis (IE) or adverse outcomes (eg, prosthetic heart valves, patients with previous IE, unrepaired cyanotic congenital heart disease, repaired congenital heart disease with prosthetic material or device during first 6 months after procedure, repaired congenital heart disease with residual defects at the site or adjacent to site of prosthetic patch or device, and heart transplant recipients with cardiac valvulopathy):
Dental, oral, or respiratory tract procedures (eg, tonsillectomy, adenoidectomy): Infants, Children, and Adolescents: IM, IV: 50 mg/kg within 30 to 60 minutes before procedure; maximum dose: 2,000 mg/dose. IM injections should be avoided in patients who are receiving anticoagulant therapy. In these circumstances, orally administered regimens should be given whenever possible. Intravenously administered antibiotics should be used for patients who are unable to tolerate or absorb oral medications (Wilson 2007).
Endocarditis treatment (off-label): Children and Adolescents: IV: 200 to 300 mg/kg/day divided every 4 to 6 hours; maximum daily dose: 12 g/day; use in combination with other antibiotics for at least 4 weeks; some organisms may require longer duration (AHA [Baltimore 2015])
Genitourinary or gastrointestinal infections:
Infants and Children ≤20 kg: 100 mg/kg/day in divided doses 4 times daily
Children and Adolescents >20 kg: 500 mg 4 times daily
Infants and Children <40 kg: 50 mg/kg/day in divided doses every 6 to 8 hours
Children and Adolescents ≥40 kg: 500 mg every 6 hours
Mild to moderate infections: Infants, Children, and Adolescents:
Oral: 50 to 100 mg/kg/day divided every 6 hours (maximum: 2 to 4 g/day) (Red Book [AAP 2012])
IM, IV: 100 to 150 mg/kg/day divided every 6 hours (maximum: 2 to 4 g/day) (Red Book [AAP 2012])
Respiratory tract infections:
Infants and Children ≤20 kg: 50 mg/kg/day in divided doses 3 to 4 times daily
Children and Adolescents >20 kg: 250 mg 4 times daily
Infants and Children <40 kg: 25 to 50 mg/kg/day in divided doses every 6 to 8 hours
Children and Adolescents ≥40 kg: 250 to 500 mg every 6 hours
Severe infections, meningitis, septicemia:
Infants, Children, and Adolescents: IM, IV: Note: Treatment should be initiated with IV infusion therapy and may be continued with IM injections if preferred.
Manufacturer’s labeling: 150 to 200 mg/kg/day in divided doses every 3 to 4 hours
Alternative recommendation: 200 to 400 mg/kg/day in divided doses every 6 hours (maximum: 12 g/day) (Red Book [AAP 2012])
Surgical (perioperative) prophylaxis in liver transplantation (off-label use): Children ≥1 year: IV: 50 mg/kg within 60 minutes prior to surgery (maximum: 2,000 mg/dose) in combination with cefotaxime. Doses may be repeated in 2 hours if procedure is lengthy or if there is excessive blood loss (Bratzler 2013).
Dosing: Renal Impairment
There are no dosage adjustments provided in the manufacturer’s labeling; however, the following adjustments have been recommended (Aronoff 2007):
CrCl >50 mL/minute: Administer every 6 hours
CrCl 10 to 50 mL/minute: Administer every 6 to 12 hours
CrCl <10 mL/minute: Administer every 12 to 24 hours
End-stage renal disease (ESRD) on intermittent hemodialysis (IHD) (administer after hemodialysis on dialysis days): Dialyzable (20% to 50%): IV: 1 to 2 g every 12 to 24 hours (administer after hemodialysis on dialysis days) (Heintz 2009). Note: Dosing dependent on the assumption of 3 times/week, complete IHD sessions.
Peritoneal dialysis (PD): IV: 250 mg every 12 hours (Aronoff, 2007)
Continuous renal replacement therapy (CRRT) (Heintz, 2009): Drug clearance is highly dependent on the method of renal replacement, filter type, and flow rate. Appropriate dosing requires close monitoring of pharmacologic response, signs of adverse reactions due to drug accumulation, as well as drug concentrations in relation to target trough (if appropriate). The following are general recommendations only (based on dialysate flow/ultrafiltration rates of 1 to 2 L/hour and minimal residual renal function) and should not supersede clinical judgment: IV:
CVVH: Loading dose of 2 g followed by 1 to 2 g every 8 to 12 hours
CVVHD: Loading dose of 2 g followed by 1 to 2 g every 8 hours
CVVHDF: Loading dose of 2 g followed by 1 to 2 g every 6 to 8 hours
Dosing: Hepatic Impairment
There are no dosage adjustments provided in the manufacturer’s labeling.
Note: Do not use bacteriostatic water for injection as vial diluent for neonatal administration.
IM: Dissolve contents of vial in sterile water for injection or bacteriostatic water for injection; final concentration for IM injection is 125 mg/mL or 250 mg/mL. Solutions for IM injection should be freshly prepared and used within 1 hour.
Direct IV use: Dissolve contents of 125 mg, 250 mg, or 500 mg vial in 5 mL SWFI or bacteriostatic water for injection. Alternatively, dissolve contents of 1 g or 2 g vial in 7.4 or 14.8 mL SWFI or bacteriostatic water for injection, respectively.
Intermittent infusion: Minimum volume: Concentration should not exceed 30 mg/mL due to concentration-dependent stability restrictions. Usual diluent: 500 mg/50 mL NS; 1 g/50 mL NS; 2 g/100 mL NS.
Administer around-the-clock to promote less variation in peak and trough serum levels.
Oral: Administer on an empty stomach with a full glass (8 oz) of water (ie, 30 minutes prior to or 2 hours after meals) to increase total absorption.
IM.: Inject deep IM into a large muscle mass
IV: Direct IV bolus: Administer over 3 to 5 minutes (125 to 500 mg) or over 10 to 15 minutes (1 to 2 g). More rapid infusion may cause seizures.
Infusion: Rapid infusion may cause seizures. Adjust rate of infusion so that the total dose is administered before admixture stability expires.
Take on an empty stomach 30 minutes before or 2 hours after meals. Some products may contain sodium.
Capsules: Store at 20°C to 25°C (68°F to 77°F).
Oral suspension: Store dry powder at 20°C to 25°C (68°F to 77°F). Once reconstituted, oral suspension is stable for 14 days under refrigeration.
Store intact vials at 20°C to 25°C (68°F to 77°F).
Solutions for IM or direct IV should be used within 1 hour.
Stability of parenteral admixture in NS at 25°C (77°F) is 8 hours (concentrations up to 30 mg/mL) and at 4°C (39°F) is 24 hours (concentration of 30 mg/mL) or 48 hours (concentrations up to 20 mg/mL). Protect from freezing.
Acemetacin: May increase the serum concentration of Penicillins. Monitor therapy
Allopurinol: May enhance the potential for allergic or hypersensitivity reactions to Ampicillin. Monitor therapy
Atenolol: Ampicillin may decrease the bioavailability of Atenolol. Monitor therapy
BCG (Intravesical): Antibiotics may diminish the therapeutic effect of BCG (Intravesical). Avoid combination
BCG Vaccine (Immunization): Antibiotics may diminish the therapeutic effect of BCG Vaccine (Immunization). Monitor therapy
Chloroquine: May decrease the serum concentration of Ampicillin. Management: Chloroquine prescribing information recommends separating administration of ampicillin and chloroquine by at least 2 hours to minimize any potential negative impact of chloroquine on ampicillin bioavailability. Consider therapy modification
Cholera Vaccine: Antibiotics may diminish the therapeutic effect of Cholera Vaccine. Avoid combination
Lactobacillus and Estriol: Antibiotics may diminish the therapeutic effect of Lactobacillus and Estriol. Monitor therapy
Lanthanum: May decrease the serum concentration of Ampicillin. Management: Administer oral ampicillin at least two hours before or after lanthanum. Consider therapy modification
Methotrexate: Penicillins may increase the serum concentration of Methotrexate. Monitor therapy
Mycophenolate: Penicillins may decrease serum concentrations of the active metabolite(s) of Mycophenolate. This effect appears to be the result of impaired enterohepatic recirculation. Monitor therapy
Probenecid: May increase the serum concentration of Penicillins. Management: Avoid the routine use of penicillins and probenecid, but this combination may be used advantageously in select cases with careful monitoring. Monitor for toxic effects of penicillins if probenecid is initiated or the dose is increased. Consider therapy modification
Sodium Picosulfate: Antibiotics may diminish the therapeutic effect of Sodium Picosulfate. Management: Consider using an alternative product for bowel cleansing prior to a colonoscopy in patients who have recently used or are concurrently using an antibiotic. Consider therapy modification
Tetracyclines: May diminish the therapeutic effect of Penicillins. Consider therapy modification
Typhoid Vaccine: Antibiotics may diminish the therapeutic effect of Typhoid Vaccine. Only the live attenuated Ty21a strain is affected. Management: Vaccination with live attenuated typhoid vaccine (Ty21a) should be avoided in patients being treated with systemic antibacterial agents. Use of this vaccine should be postponed until at least 3 days after cessation of antibacterial agents. Consider therapy modification
Vitamin K Antagonists (eg, warfarin): Penicillins may enhance the anticoagulant effect of Vitamin K Antagonists. Monitor therapy
May interfere with urinary glucose tests using cupric sulfate (Benedict's solution, Clinitest®)
Some penicillin derivatives may accelerate the degradation of aminoglycosides in vitro, leading to a potential underestimation of aminoglycoside serum concentration.
Frequency not defined.
Central nervous system: Brain disease (penicillin-induced), glossalgia, seizure, sore mouth
Dermatologic: Erythema multiforme, exfoliative dermatitis, skin rash, urticaria
Note: Appearance of a rash should be carefully evaluated to differentiate (if possible) nonallergic ampicillin rash from hypersensitivity reaction. Incidence is higher in patients with viral infection, Salmonella infection, lymphocytic leukemia, or patients that have hyperuricemia.
Gastrointestinal: Diarrhea, enterocolitis, glossitis, melanoglossia, nausea, oral candidiasis, pseudomembranous colitis, stomatitis, vomiting
Hematologic & oncologic: Agranulocytosis, anemia, eosinophilia, hemolytic anemia, immune thrombocytopenia, leukopenia
Hepatic: Increased serum AST
Immunologic: Serum sickness-like reaction
Renal: Interstitial nephritis (rare)
<1%, postmarketing, and/or case reports: Dysgeusia (Syed 2016)
Concerns related to adverse effects:
• Hypersensitivity/anaphylactoid reactions: Serious and occasionally severe or fatal hypersensitivity (anaphylactoid) reactions have been reported in patients on penicillin therapy, especially with a history of beta-lactam hypersensitivity or a history of sensitivity to multiple allergens. Serious anaphylactoid reactions require emergency treatment and airway management. Appropriate treatments must be readily available.
• Rash: Appearance of a rash should be carefully evaluated to differentiate a nonallergic ampicillin rash from a hypersensitivity reaction; rash occurs in 5% to 10% of children and is a generalized dull red, maculopapular rash, generally appearing 3 to 14 days after the start of therapy. It normally begins on the trunk and spreads over most of the body. It may be most intense at pressure areas, elbows, and knees.
• Superinfection: Prolonged use may result in fungal or bacterial superinfection, including Clostridium difficile-associated diarrhea (CDAD) and pseudomembranous colitis; CDAD has been observed >2 months postantibiotic treatment.
• Infectious mononucleosis: A high percentage of patients with infectious mononucleosis have developed rash during therapy; ampicillin-class antibiotics not recommended in these patients. Rash (generalized maculopapular and pruritic) usually appears 7 to 10 days after initiation and usually resolves within a week of discontinuation. It is not known whether these patients are truly allergic to ampicillin
• Renal impairment: Use with caution in patients with renal impairment; dosage adjustment recommended.
With prolonged therapy, monitor renal, hepatic, and hematologic function periodically; observe signs and symptoms of anaphylaxis during first dose
Pregnancy Risk Factor
Adverse events have not been observed in animal reproduction studies. Ampicillin crosses the placenta, providing detectable concentrations in the cord serum and amniotic fluid (Bolognese 1968; Fisher 1967; MacAulay 1966). Maternal use of ampicillin has generally not resulted in an increased risk of birth defects (Aselton 1985; Czeizel 2001b; Heinonen 1977; Jick 1981; Puhó 2007). Ampicillin is recommended for use in pregnant women for the management of preterm prelabor rupture of membranes (PROM) and for the prevention of early-onset group B streptococcal (GBS) disease in newborns. Ampicillin may also be used in certain situations prior to vaginal delivery in women at high risk for endocarditis (ACOG 120 2011; ACOG 188 2018; ACOG 485 2011; CDC [RR-10] 2010).
The volume of distribution of ampicillin is increased during pregnancy and the half-life is decreased. As a result, serum concentrations in pregnant patients are approximately 50% of those in nonpregnant patients receiving the same dose. Higher doses may be needed during pregnancy. Although oral absorption is not altered during pregnancy, oral ampicillin is poorly absorbed during labor (Philipson 1977; Philipson 1978; Wasz-Höckert 1970).
• Discuss specific use of drug and side effects with patient as it relates to treatment. (HCAHPS: During this hospital stay, were you given any medicine that you had not taken before? Before giving you any new medicine, how often did hospital staff tell you what the medicine was for? How often did hospital staff describe possible side effects in a way you could understand?)
• Patient may experience nausea, vomiting, or diarrhea. Have patient report immediately to prescriber severe loss of strength and energy; bruising; bleeding; chills; pharyngitis; black, hairy tongue; mouth irritation; mouth sores; seizures; or signs of Clostridium difficile (C. diff)-associated diarrhea (abdominal pain or cramps, severe diarrhea or watery stools, or bloody stools) (HCAHPS).
• Educate patient about signs of a significant reaction (eg, wheezing; chest tightness; fever; itching; bad cough; blue skin color; seizures; or swelling of face, lips, tongue, or throat). Note: This is not a comprehensive list of all side effects. Patient should consult prescriber for additional questions.
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