Medically reviewed on Sep 10, 2018
(a moks i SIL in)
- Amoxicillin Trihydrate
Excipient information presented when available (limited, particularly for generics); consult specific product labeling. [DSC] = Discontinued product
Generic: 250 mg, 500 mg
Suspension Reconstituted, Oral:
Generic: 125 mg/5 mL (80 mL, 100 mL, 150 mL); 200 mg/5 mL (50 mL, 75 mL, 100 mL); 250 mg/5 mL (80 mL, 100 mL, 150 mL); 400 mg/5 mL (50 mL, 75 mL, 100 mL)
Generic: 500 mg, 875 mg
Tablet Chewable, Oral:
Generic: 125 mg, 250 mg
Tablet Extended Release 24 Hour, Oral:
Moxatag: 775 mg [contains cremophor el, fd&c blue #2 aluminum lake]
Generic: 775 mg [DSC]
Brand Names: U.S.
- 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.
Oral: Immediate-release: Rapid with or without food
Extended-release: Rate of absorption is slower compared to immediate-release formulations; food decreases the rate but not extent of absorption
Readily into liver, lungs, prostate, muscle, middle ear effusions, maxillary sinus secretions, bone, gallbladder, bile, and into ascitic and synovial fluids; poor CSF penetration (except when meninges are inflamed)
Urine (60% as unchanged drug); lower in neonates
Time to Peak
Capsule; oral suspension: 1 to 2 hours; Chewable tablet: 1 hour; Extended-release tablet: 3.1 hours
Adults: Immediate-release: 61.3 minutes; Extended-release: 90 minutes
Use: Labeled Indications
Ear, nose, and throat infections (pharyngitis/tonsillitis, otitis media, rhinosinusitis): Immediate-release: Treatment of infections due to beta-lactamase-negative Streptococcus spp (alpha- and beta-hemolytic isolates only), Streptococcus pneumoniae, Staphylococcus spp., or Haemophilus influenzae.
Genitourinary tract infections: Immediate-release: Treatment of infections of the genitourinary tract due to beta-lactamase-negative Escherichia coli, Proteus mirabilis, or Enterococcus faecalis.
Helicobacter pylorieradication: Immediate-release: Eradication of H. pylori to reduce the risk of duodenal ulcer recurrence as a component of combination therapy in patients with active or 1 year history of duodenal ulcer disease.
Lower respiratory tract infections (including pneumonia): Immediate-release: Treatment of infections of the lower respiratory tract due to beta-lactamase-negative Streptococcus spp. (alpha- and beta-hemolytic strains only), Streptococcus pneumoniae, Staphylococcus spp., or H. influenzae.
Pharyngitis and tonsillitis: Extended-release: Treatment of tonsillitis and/or pharyngitis due to Streptococcus pyogenes in adults and pediatric patients ≥12 years.
Skin and skin structure infections: Immediate-release: Treatment of infections of the skin and skin structure due to beta-lactamase-negative Streptococcus spp. (alpha- and beta-hemolytic strains only), Staphylococcus spp., or E. coli.
Off Label Uses
Anthrax, inhalational post-exposure prophylaxis (documented susceptible organisms) (adults)
Based on the Centers for Disease Control and Prevention (CDC) recommendations for the post-exposure prophylaxis of inhalational anthrax, amoxicillin is an effective and recommended alternative drug in the management of post-exposure prophylaxis of inhalational anthrax in patients with documented susceptible organisms if first-line agents are not tolerated or are unavailable ([CDC [Hendricks 2014]].
Anthrax, inhalational post-exposure prophylaxis (documented susceptible organisms) (children)
Based on the American Academy of Pediatrics recommendations for the post-exposure prophylaxis of inhalational anthrax, amoxicillin is an effective and recommended drug in the management of post-exposure prophylaxis of inhalational anthrax in patients with documented susceptible organisms [AAP [Bradley 2014]].
Community-acquired pneumonia (children)
Following clinical guideline recommendations on the management of CAP reduces the incidence of morbidity and mortality related to pneumonia. In children older than 3 months of age, amoxicillin is the preferred oral option for empirical treatment of suspected bacterial CAP and for pathogen-directed therapy aimed at S. pneumoniae, GAS, or beta-lactamase-negative H. influenzae.
Based on the Infectious Diseases Society of America (IDSA) guidelines for the diagnosis and management of skin and soft tissue infections (SSTI), amoxicillin is an effective and recommended treatment of erysipeloid [IDSA [Stevens 2014]].
Group A streptococcal pharyngitis (children)
Group A streptococcus is the most common bacterial cause of acute pharyngitis. The safety and efficacy profiles of penicillin and amoxicillin make either agent the drug of choice in non-penicillin-allergic patients. Amoxicillin offers once-daily dosing and is available as a child-friendly palatable suspension, which may help increase compliance and reduce clinical failure in children.
Infective endocarditis (prophylaxis)
Based on the American Heart Association (AHA) guidelines for the prevention of infective endocarditis, amoxicillin is effective and recommended for administration to patients with certain cardiac conditions who are able to take oral medication to provide prophylaxis against infective endocarditis associated with dental or respiratory tract procedures and for patients undergoing genitourinary procedures to eradicate enterococci from the urine unless a known or suspected strain of resistant enterococci exists.
Lyme disease (excluding neurologic disease)
Based on the Infectious Diseases Society of America guidelines for the clinical assessment, treatment and prevention of Lyme disease, human granulocytic anaplasmosis, and babesiosis, amoxicillin is effective and recommended for the treatment of early localized or early disseminated Lyme disease associated with erythema migrans (in the absence of specific neurologic manifestations or advanced atrioventricular heart block) Lyme arthritis, Lyme carditis (mild), and acrodermatitis chronica atrophicans.
Parenteral regimens for Lyme disease of the nervous system have a greater potential for morbidity. For severe neurologic disease, class 1 and 2 studies suggested that parenteral treatment was probably safe and effective, but class 2 and 3 studies also indicated that oral therapy (and doxycycline specifically) was comparably safe and effective for patients without parenchymal involvement. The evidence for oral therapy is stronger in adults than in children, but no results indicate that children respond differently than adults. The use of amoxicillin as an alternative oral therapy to doxycycline was supported by inference only.[AAN [Halperin 2007]]
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 amoxicillin (among other antibiotics) was suggested for patients not allergic to penicillin [ADA/AAOS 2003].
Prosthetic joint infection
Based on the Infectious Diseases Society of America (IDSA) guidelines for the management of prosthetic joint infection, amoxicillin is an effective and recommended agent for chronic oral antimicrobial suppression of prosthetic joint infection with beta-hemolytic streptococci, Enterococcus spp (penicillin susceptible), and Cutibacterium spp after completion of parenteral therapy.
Serious hypersensitivity to amoxicillin (eg, anaphylaxis, Stevens-Johnson syndrome) or to other beta-lactams, or any component of the formulation
Canadian labeling: Additional contraindications (not in US labeling): Infectious mononucleosis (suspected or confirmed)
Note: Unless otherwise specified, all dosing recommendations based on immediate release product formulations.
Usual dosage range: Oral:
Mild or moderate infection: 250 mg every 8 hours or 500 mg every 12 hours
Mild or moderate infection (lower respiratory tract): 500 mg every 8 hours or 875 mg every 12 hours
Severe infection (as step-down therapy): 500 mg every 8 hours or 875 mg every 12 hours
Extended-release: 775 mg once daily
Anthrax, inhalational postexposure prophylaxis (CDC recommendations) (off-label use): Oral: 1,000 mg every 8 hours (Hendricks [CDC 2014]). Note: Use only if isolates of the specific B. anthracis are sensitive to amoxicillin (MIC ≤0.125 mcg/mL); may be administered to pregnant and breast-feeding women. Duration of antibiotic postexposure prophylaxis (PEP) is 60 days whether a patient is vaccinated, partially vaccinated, or unvaccinated (Hendricks [CDC 2014]).
Ear, nose, throat, genitourinary tract, or skin/skin structure infections: Note: IDSA guidelines recommend amoxicillin-clavulanate as preferred first-line treatment of acute bacterial rhinosinusitis (ABRS) (IDSA [Chow 2012]); AAO-HNS guidelines for adult sinusitis recommend either amoxicillin or amoxicillin-clavulanate as initial first-line therapy of ABRS, with consideration given for amoxicillin-clavulanate instead of amoxicillin in certain patients (eg, moderate to severe ABRS symptoms, antibiotic use in past month, high prevalence of resistant bacteria in community, history of recurrent ABRS, presence of comorbidities) (AAO-HNS [Rosenfeld 2015]).
Mild-to-moderate: Oral: 500 mg every 12 hours or 250 mg every 8 hours
Severe: Oral: 875 mg every 12 hours or 500 mg every 8 hours
Tonsillitis and/or pharyngitis: Oral: Extended release: 775 mg once daily for 10 days
Endocarditis, prophylaxis (off-label use): Oral: 2 g 30 to 60 minutes before procedure. Note: American Heart Association (AHA) guidelines now recommend prophylaxis only in patients undergoing invasive procedures and in who underlying cardiac conditions may predispose to a higher risk of adverse outcomes should infection occur. As of April 2007, routine prophylaxis for GI/GU procedures is no longer recommended by the AHA.
Erysipeloid (off-label use): Oral: 500 mg 3 times daily for 7 to 10 days (IDSA [Stevens 2014])
Helicobacter pylori eradication: Oral:
American College of Gastroenterology guidelines (Chey 2007; Chey 2017):
Clarithromycin triple therapy: 1,000 mg twice daily in combination with clarithromycin 500 mg twice daily plus a standard-dose or double-dose proton pump inhibitor; continue regimen for 14 days. Note: Avoid use of clarithromycin triple therapy in patients with risk factors for macrolide resistance (eg, prior macrolide exposure, local clarithromycin resistance rates ≥15%, eradication rates with clarithromycin-based regimens ≤85%) (ACG [Chey 2017]; Fallone 2016).
Concomitant regimen: 1,000 mg twice daily in combination with clarithromycin 500 mg twice daily, and either metronidazole or tinidazole 500 mg twice daily, plus a standard-dose proton pump inhibitor twice daily; continue regimen for 10 to 14 days.
Sequential regimen: 1,000 mg twice daily plus a standard-dose proton pump inhibitor twice daily for 5 to 7 days; then follow with clarithromycin 500 mg twice daily, and either metronidazole or tinidazole 500 mg twice daily, and a standard-dose proton pump inhibitor twice daily for 5 to 7 days.
Hybrid regimen: 1,000 mg twice daily plus a standard-dose proton pump inhibitor twice daily for 7 days; then follow with amoxicillin 1,000 mg twice daily, clarithromycin 500 mg twice daily, and either metronidazole or tinidazole 500 mg twice daily, and a standard-dose proton pump inhibitor twice daily for 7 days.
Levofloxacin triple regimen: 1,000 mg twice daily in combination with a standard-dose proton pump inhibitor twice daily and levofloxacin 500 mg once daily; continue regimen for 10 to 14 days.
Lower respiratory tract infections: Oral:
Manufacturer's labeling: 875 mg every 12 hours or 500 mg every 8 hours
Alternate dosing: Pneumonia, community-acquired: Outpatient empiric therapy: 1,000 mg 3 times daily for a minimum of 5 days (patients should be afebrile for ≥48 hours and clinically stable before discontinuation of therapy); use in combination with a macrolide (preferred) or doxycycline (Mandell 2007)
Lyme disease (excluding neurologic disease) (off-label use) (IDSA [Wormser 2006]): Oral:
Acrodermatitis chronica atrophicans: 500 mg 3 times daily for 21 days
Erythema migrans: 500 mg 3 times daily for 14 to 21 days
Lyme arthritis: 500 mg 3 times daily for 28 days
Lyme carditis (mild): 500 mg 3 times daily for 14 to 21 days
Lyme neuroborreliosis (off-label use) (when doxycycline is contraindicated): Oral: 500 mg 3 times daily for 14 to 21 days. Note: Oral regimens should be reserved for patients with cranial nerve palsy without evidence of meningitis (IDSA [Wormser 2006]).
Periodontitis (aggressive) (in combination with metronidazole) associated with presence of Actinobacillus actinomycetemcomitans (AA) (off-label use): Oral: 500 mg every 8 hours for 10 days used in addition to scaling and root planing (Varela 2011)
Pharyngitis, group A streptococci: Oral: 1,000 mg once daily or 500 mg twice daily (maximum: 1,000 mg/day) for 10 days (IDSA [Shulman 2012])
Prophylaxis in total joint replacement patients undergoing dental procedures which produce bacteremia (off-label use): Oral: 2 g 1 hour prior to procedure (ADA/AAOS 2003). 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).
Prosthetic joint infection, chronic antimicrobial suppression of prosthetic joint infection associated with beta-hemolytic streptococci, penicillin-susceptible Enterococcus spp, or Cutibacterium spp (off-label use): Oral: 500 mg 3 times daily (Osmon 2013)
Refer to adult dosing.
Note: Unless otherwise specified, all pediatric dosing recommendations based on immediate release product formulations (oral suspension, chewable tablet, tablet, and capsule).
Usual dosage range:
Mild to moderate infection:
Infants ≤3 months: Oral: 25 to 50 mg/kg/day in divided doses every 8 hours (Red Book [AAP 2015]). Note: Manufacturer's labeling recommends a maximum daily dose of 30 mg/kg/day divided into 2 doses per day for this age group.
Infants >3 months, Children, and Adolescents (<40 kg):
AAP recommendations (Red Book [AAP 2015]): Oral: 25 to 50 mg/kg/day in divided doses every 8 hours; maximum dose: 500 mg/dose
Manufacturer's labeling: Oral: 20 to 40 mg/kg/day in divided doses every 8 hours (maximum dose: 500 mg/dose) or 25 to 45 mg/kg/day in divided doses every 12 hours (maximum dose: 875 mg/dose)
Children, and Adolescents (≥40 kg): Refer to adult dosing.
Severe infection (as step-down therapy): Infants, Children, and Adolescents: Oral: 80 to 100 mg/kg/day in divided doses every 8 hours; maximum dose: 500 mg/dose for most indications (Red Book [AAP 2015])
Anthrax (off-label use):
Cutaneous, without systemic involvement: Children and Adolescents: Oral: 75 mg/kg/day in 3 divided doses. Maximum dose: 1,000 mg/dose. Duration of therapy: 7 to 10 days for naturally acquired infection, up to 60 days for biological weapon-related exposure (AAP [Bradley 2014]).
Inhalational, postexposure prophylaxis: Children and Adolescents: Oral: 75 mg/kg/day in divided doses every 8 hours for 60 days after exposure; maximum dose: 1,000 mg/dose (AAP [Bradley 2014]).
Catheter (peritoneal dialysis), exit-site or tunnel infection (off-label use): Infants, Children, and Adolescents: Oral: 10 to 20 mg/kg once daily; maximum dose: 1,000 mg/dose (Warady [ISPD 2012])
Endocarditis, prophylaxis (off-label use): Infants, Children, and Adolescents: Oral: 50 mg/kg 1 hour before procedure (maximum dose: 2,000 mg/dose) (Wilson 2007)
Helicobacter pylori eradication: Children and Adolescents: Oral: 50 mg/kg/day in 2 divided doses for 10 to 14 days; maximum daily dose: 2,000 mg/day. Administer in combination with a proton pump inhibitor or bismuth subsalicylate and at least one other antibiotic (clarithromycin and/or metronidazole) (NASPGHAN/ESPGHAN [Koletzko 2011]).
Lyme disease (off-label use): Infants, Children, and Adolescents: Oral: 50 mg/kg/day divided every 8 hours (maximum dose: 500 mg/dose) (Halperin 2007; Wormser 2006)
Otitis media, acute: Infants ≥2 months and Children: Oral: 80 to 90 mg/kg/day divided every 12 hours; variable duration of therapy, if <2 years of age or severe symptoms (any age): 10-day course; if 2 to 5 years of age with mild to moderate symptoms: 7-day course; ≥6 years of age with mild to moderate symptoms: 5- to 7-day course; some experts recommend initiating with 90 mg/kg/day (AAP [Lieberthal 2013]; Red Book [AAP 2015]); a maximum dose is not provided in the Guidelines for The Diagnosis and Management of Acute Otitis Media (AAP [Lieberthal 2013]); however, some experts suggest a maximum daily dose of 4,000 mg/day for high-dose amoxicillin therapy (Bradley 2015).
Peritonitis, prophylaxis (for patients receiving peritoneal dialysis who require dental procedures) (off-label use): Infants, Children, and Adolescents: Oral: 50 mg/kg administered 30 to 60 minutes before dental procedure (maximum dose: 2000 mg/dose) (Warady [ISPD 2012])
Pneumococcal infection prophylaxis for anatomic or functional asplenia (eg, sickle cell disease ([SCD]) (off-label use) (Price 2007; Red Book [AAP 2015]):
Infants (<2 months to 1 year, or as soon as SCD is diagnosed or asplenia occurs) and Children ≤5 years: Oral: 20 mg/kg/day in divided doses every 12 hours (maximum dose: 250 mg/dose)
Children ≥6 years and Adolescents: Oral: 250 mg every 12 hours. Note: The decision to discontinue penicillin prophylaxis after 5 years of age in children who have not experienced invasive pneumococcal infection and have received recommended pneumococcal immunizations is patient and clinician dependent.
Pneumonia, community-acquired (CAP) (Bradley [IDSA 2011]): Infants ≥3 months, Children, and Adolescents: Note: In pediatric patients 5 to 15 years of age, a macrolide antibiotic may be a more reasonable first choice as M. pneumoniae is the chief cause of pneumonia in this age group.
Empiric treatment: Oral: 90 mg/kg/day in divided doses every 12 hours (maximum daily dose: 4,000 mg/day)
Group A Streptococcus: Oral: 50 to 75 mg/kg/day in divided doses every 12 hours (maximum daily dose: 4,000 mg/day)
H. influenzae: Oral: 75 to 100 mg/kg/day in divided doses every 8 hours (maximum daily dose: 4,000 mg/day)
S. pneumoniae (MICs to penicillin ≤2 mcg/mL), mild infection or step-down therapy: Oral: 90 mg/kg/day in divided doses every 12 hours or 45 mg/kg/day in divided doses every 8 hours (maximum daily dose: 4,000 mg/day)
Rhinosinusitis, acute bacterial; uncomplicated: Note: AAP guidelines recommend amoxicillin as first-line empiric therapy for pediatric patients 1 to 18 years with uncomplicated cases and where resistance is not suspected; however, the IDSA guidelines consider amoxicillin/clavulanate as the preferred therapy (Chow 2012, Wald 2013):
Children and Adolescents:
Low dose: Oral: 45 mg/kg/day in divided doses every 12 hours
High dose (use reserved for select patients; see Note): Oral: 80 to 90 mg/kg/day in divided doses every 12 hours (maximum dose: 1,000 mg/dose). Note: Should only be used in the following: Mild to moderate infections in communities with a high prevalence of nonsusceptible S. pneumoniae resistance.
Tonsillopharyngitis; Group A streptococcal infection, treatment and primary prevention of rheumatic fever:
Immediate release: Children ≥3 years and Adolescents: Oral: 50 mg/kg once daily or 25 mg/kg twice daily for 10 days; maximum daily dose: 1,000 mg/day (Gerber 2009; Shulman 2012)
Extended release: Children ≥12 years and Adolescents: Oral: 775 mg once daily for 10 days. Note: Patient must be able to swallow tablet whole.
Urinary tract infection, prophylaxis (hydronephrosis, vesicoureteral reflux): Infants ≤2 months: Oral: 10 to 15 mg/kg once daily; some suggest administration in the evening (drug resides in bladder longer); Note: Due to resistance, amoxicillin should not be used for prophylaxis after 2 months of age (Belarmino 2006; Greenbaum 2006; Mattoo 2007).
Dosing: Renal Impairment
Immediate-release: Note: Avoid immediate-release 875 mg tablet in patients with GFR <30 mL/minute.
GFR ≥30 mL/minute: No dosage adjustment necessary.
GFR 10 to 30 mL/minute: 250 to 500 mg every 12 hours
GFR <10 mL/minute: 250 to 500 mg every 24 hours
Hemodialysis: Moderately dialyzable (20% to 50%); ~30% removed by 3-hour hemodialysis: 250 to 500 mg every 24 hours; administer after dialysis on dialysis days (Aronoff 2007)
CrCl ≥30 mL/minute: There are no dosage adjustments provided in the manufacturer’s labeling (has not been studied).
CrCl <30 mL/minute: Not recommended
Hemodialysis: Not recommended.
Infants, Children, and Adolescents: Oral:
There are no dosage adjustments provided in the manufacturer’s labeling; however, the following recommendations have been used by some clinicians (Aronoff 2007):
Mild to moderate infection: Dosing based on 25 to 50 mg/kg/day divided every 8 hours:
GFR ≥30 mL/minute/1.73 m2: No dosage adjustment necessary.
GFR 10 to 29 mL/minute/1.73 m2: 8 to 20 mg/kg/dose every 12 hours
GFR <10 mL/minute/1.73 m2: 8 to 20 mg/kg/dose every 24 hours
Hemodialysis: Moderately dialyzable (20% to 50%); ~30% removed by 3-hour hemodialysis: 8 to 20 mg/kg/dose every 24 hours; give after dialysis.
Peritoneal dialysis: 8 to 20 mg/kg/dose every 24 hours.
Severe infection (high dose): Dosing based on 80 to 90 mg/kg/day divided every 12 hours:
GFR ≥30 mL/minute/1.73 m2: No dosage adjustment necessary.
GFR 10 to 29 mL/minute/1.73 m2: 20 mg/kg/dose every 12 hours; do not use the 875 mg tablet.
GFR <10 mL/minute/1.73 m2: 20 mg/kg/dose every 24 hours; do not use the 875 mg tablet.
Hemodialysis: Moderately dialyzable (20% to 50%); ~30% removed by 3-hour hemodialysis: 20 mg/kg/dose every 24 hours; give after dialysis.
Peritoneal dialysis: 20 mg/kg/dose every 24 hours
Extended-release: Children ≥12 years and Adolescents:
CrCl ≥30 mL/minute: There are no dosage adjustments provided in the manufacturer’s labeling (has not been studied).
CrCl <30 mL/minute: Not recommended.
Hemodialysis: Not recommended.
Dosing: Hepatic Impairment
There are no dosage adjustments provided in the manufacturer’s labeling.
Oral suspension: Refer to manufacturer’s product labeling for reconstitution instructions. Shake vigorously.
Oral: Administer around-the-clock to promote less variation in peak and trough serum levels.
Extended release: Administer within 1 hour of finishing a meal; do not chew or crush tablet.
Suspension: Shake well before use; may be mixed with formula, milk, fruit juice, water, ginger ale, or cold drinks; administer dose immediately after mixing.
Some products may contain phenylalanine.
Store at room temperature. Reconstituted oral suspension remains stable for 14 days at room temperature or refrigerated (refrigeration preferred). Unit-dose antibiotic oral syringes are stable at room temperature for at least 72 hours (Tu 1988).
Acemetacin: May increase the serum concentration of Penicillins. Monitor therapy
Allopurinol: May enhance the potential for allergic or hypersensitivity reactions to Amoxicillin. 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
Cholera Vaccine: Antibiotics may diminish the therapeutic effect of Cholera Vaccine. Management: Avoid cholera vaccine in patients receiving systemic antibiotics, and within 14 days following the use of oral or parenteral antibiotics. Avoid combination
Lactobacillus and Estriol: Antibiotics may diminish the therapeutic effect of Lactobacillus and Estriol. Monitor therapy
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 (Benedict's solution, Clinitest, Fehling’s Solution).
Some penicillin derivatives may accelerate the degradation of aminoglycosides in vitro, leading to a potential underestimation of aminoglycoside serum concentration.
Frequency not defined.
Cardiovascular: Hypersensitivity angiitis
Central nervous system: Agitation, anxiety, behavioral changes, confusion, dizziness, headache, hyperactivity (reversible), insomnia, seizure
Dermatologic: Acute generalized exanthematous pustulosis, erythematous maculopapular rash, erythema multiforme, exfoliative dermatitis, Stevens-Johnson syndrome, toxic epidermal necrolysis, urticaria
Gastrointestinal: Dental discoloration (brown, yellow, or gray; rare), diarrhea, hemorrhagic colitis, melanoglossia, mucocutaneous candidiasis, nausea, pseudomembranous colitis, vomiting
Hematologic & oncologic: Agranulocytosis, anemia, eosinophilia, hemolytic anemia, leukopenia,thrombocytopenia, thrombocytopenia purpura
Hepatic: Cholestatic hepatitis, cholestatic jaundice, hepatitis (acute cytolytic), increased serum ALT, increased serum AST
Immunologic: Serum sickness-like reaction
Concerns related to adverse effects:
• Anaphylactic/hypersensitivity reactions: Serious and occasionally severe or fatal hypersensitivity (anaphylactic) reactions have been reported in patients on penicillin therapy, including amoxicillin, especially with a history of beta-lactam hypersensitivity (including severe reactions with cephalosporins) and/or a history of sensitivity to multiple allergens.
• Superinfection: Prolonged use may result in fungal or bacterial superinfection, including C. 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 develop an erythematous rash during amoxicillin therapy; avoid use in these patients.
• Renal impairment: Use with caution in patients with renal impairment; dosage adjustment recommended in patients with GFR <30 mL/minute. Avoid extended release 775 mg tablet and immediate release 875 mg tablet in patients with GFR <30 mL/minute or patients requiring hemodialysis.
Concurrent drug therapy issues:
• Drug-drug interactions: Potentially significant interactions may exist, requiring dose or frequency adjustment, additional monitoring, and/or selection of alternative therapy. Consult drug interactions database for more detailed information.
Dosage form specific issues:
• Benzyl alcohol and derivatives: Some dosage forms may contain sodium benzoate/benzoic acid; benzoic acid (benzoate) is a metabolite of benzyl alcohol; large amounts of benzyl alcohol (≥99 mg/kg/day) have been associated with a potentially fatal toxicity (“gasping syndrome”) in neonates; the “gasping syndrome” consists of metabolic acidosis, respiratory distress, gasping respirations, CNS dysfunction (including convulsions, intracranial hemorrhage), hypotension, and cardiovascular collapse (AAP ["Inactive" 1997]; CDC 1982); some data suggests that benzoate displaces bilirubin from protein binding sites (Ahlfors 2001); avoid or use dosage forms containing benzyl alcohol derivative with caution in neonates. See manufacturer’s labeling.
• Chewable tablets: May contain phenylalanine; see manufacturer’s labeling.
With prolonged therapy, monitor renal, hepatic, and hematologic function periodically; assess patient at beginning and throughout therapy for infection; monitor for signs of anaphylaxis during first dose
Pregnancy Risk Factor
Adverse events have not been observed in animal reproduction studies. Amoxicillin crosses the placenta (Muller 2009). Maternal use of amoxicillin has generally not resulted in an increased risk of adverse fetal effects; however, a possible association with cleft lip with cleft palate has been observed in some studies (more data is needed) (Lin 2012; Puhó 2007). Amoxicillin may be used for the management of Bacillus anthracis in pregnant women when penicillin susceptibility is documented (Meaney-Delman 2014). Amoxicillin is an alternative antibiotic for the treatment of chlamydial infections in pregnancy (CDC [Workowski 2015]). Amoxicillin can also be used in the management of preterm premature rupture of membranes and in certain situations prior to vaginal delivery in women at high risk for endocarditis (ACOG 120 2011; ACOG 139 2013).
Due to pregnancy-induced physiologic changes, some pharmacokinetic parameters of amoxicillin may be altered (Andrew 2007). Oral ampicillin-class antibiotics are poorly absorbed during labor.
• 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 signs of liver problems (dark urine, fatigue, lack of appetite, nausea, abdominal pain, light-colored stools, vomiting, or jaundice), signs of Clostridium difficile (C. diff)-associated diarrhea (abdominal pain or cramps, severe diarrhea or watery stools, or bloody stools), signs of Stevens-Johnson syndrome/toxic epidermal necrolysis (red, swollen, blistered, or peeling skin [with or without fever]; red or irritated eyes; or sores in mouth, throat, nose, or eyes), bruising, bleeding, or thrush (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.
Intended Use and Disclaimer: Should not be printed and given to patients. This information is intended to serve as a concise initial reference for healthcare professionals to use when discussing medications with a patient. You must ultimately rely on your own discretion, experience and judgment in diagnosing, treating and advising patients.
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