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Amoxicillin

Medically reviewed on Nov 15, 2018

Pronunciation

(a moks i SIL in)

Index Terms

  • p-Hydroxyampicillin
  • Amoxicillin Trihydrate
  • Amoxil
  • Amoxycillin

Dosage Forms

Excipient information presented when available (limited, particularly for generics); consult specific product labeling. [DSC] = Discontinued product

Capsule, Oral:

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)

Tablet, Oral:

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.

  • Moxatag

Pharmacologic Category

  • Antibiotic, Penicillin

Pharmacology

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.

Absorption

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

Distribution

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)

Excretion

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

Half-Life Elimination

Adults: Immediate-release: 61.3 minutes; Extended-release: 90 minutes

Protein Binding

~20%

Use: Labeled Indications

Ear, nose, and throat infections (pharyngitis/tonsillitis, otitis media):

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.

Extended-release: Treatment of tonsillitis and/or pharyngitis due to Streptococcus pyogenes in adults and pediatric patients ≥12 years of age.

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.

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

Actinomycosis

Data from a small retrospective study suggest that amoxicillin may be beneficial for the treatment of actinomycosis [Bonnefond 2016]. Clinical experience also suggests that amoxicillin may be beneficial in managing actinomycosis [Valour 2014]

Anthrax

Based on the Centers for Disease Control and Prevention (CDC) recommendations for the post-exposure prophylaxis of inhalational anthrax and the American Academy of Pediatrics 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 or treatment of cutaneous anthrax (without systemic involvement) in patients with documented susceptible organisms [AAP [Bradley 2014]], [CDC [Hendricks 2014]].

Asplenia, prophylaxis against bacterial infection in high-risk patients

Clinical experience suggests the utility of amoxicillin to prevent bacterial infections in high-risk patients with functional or anatomic asplenia [Coignard-Biehler 2010], [Pasternack 2018].

Bronchiectasis

Based on the European Respiratory Society guidelines for the management of adult bronchiectasis, the use of long-term treatment with an oral antibiotic (such as amoxicillin) based on antibiotic susceptibility and patient tolerance is recommended for adults with bronchiectasis with ≥3 exacerbations per year who are not infected with Pseudomonas aeruginosa in whom macrolides are contraindicated. Data from a small number of patients suggests the utility of long-term amoxicillin to reduce severity of exacerbations in patients with bronchiectasis [Currie 1990].

Data from a limited number of patients studied suggest that amoxicillin may be beneficial in the treatment of acute exacerbations of bronchiectasis [Prigogine 1988]. Clinical experience also suggests the utility of amoxicillin in managing bronchiectasis [Barker 2018].

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 (Borrellia spp. infection)

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 Lyme disease (eg, erythema migrans), early disseminated Lyme disease (isolated facial nerve palsy [when doxycycline is contraindicated] or mild carditis), or late Lyme disease (arthritis without neurologic involvement, acrodermatitis chronica atrophicans).

Periodontitis, generalized aggressive

Data from a small, randomized, double-blind study support the use of amoxicillin, in combination with metronidazole as well as scaling and root planing, in the treatment of aggressive periodontitis [Silva-Senem 2013]. In addition, results of a systematic review and meta-analysis support the use of amoxicillin, in combination with metronidazole and scaling and root planing, in the treatment of aggressive periodontitis [Rabelo 2015].

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.

Contraindications

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)

Dosing: Adult

Note: Unless otherwise specified, all dosing recommendations based on immediate release product formulations.

Usual dosage range: Oral: 500 to 1,000 mg every 8 to 12 hours

Extended release: 775 mg once daily

Indication-specific dosing:

Actinomycosis (off-label use): Note: For initial therapy (mild infections) or step-down therapy (following parenteral treatment): Oral: 500 mg 3 to 4 times daily (Martin 1984; Paulo 2018; Sharkaway 2018; Shikino 2015); higher doses of 4 to 6 g/day have been utilized in case reports (Moghimi 2013; Valour 2014).

Anthrax (alternative agent for penicillin-susceptible strains) (off-label use): Note: Consult public health officials for event-specific recommendations.

Inhalational exposure postexposure prophylaxis: Oral: 1 g every 8 hours for 60 days. Note: Anthrax vaccine should also be administered to exposed individuals (CDC [Hendricks 2014]).

Cutaneous, without systemic involvement: Oral: 1 g every 8 hours for 60 days following biological weapon-related event; duration is 7 to 10 days after naturally acquired infection. Note: Patients with cutaneous lesions of the head or neck or extensive edema should be treated for systemic involvement (CDC [Hendricks 2014]).

Asplenia, prophylaxis against bacterial infection in high-risk patients (off-label use): Note: Routine prophylaxis is not recommended in all adults but may be considered in highly immunocompromised patients and/or survivors of an episode of pneumococcal sepsis (based on expert opinion). Oral: 250 to 500 mg twice daily (Pasternack 2018).

Bronchiectasis (off-label use):

Prevention of pulmonary exacerbations (dosing based on expert opinion): Oral: 500 mg twice daily; based on expert opinion (Barker 2018). Note: Recommended for patients with ≥3 exacerbations per year; for those who are not colonized with Pseudomonas aeruginosa and not candidates for long-term macrolide therapy (Barker 2018; ERS [Polverino 2017]).

Treatment of pulmonary exacerbations in patients without beta-lactamase-positive Haemophilus influenzae or P. aeruginosa: Oral: 500 mg 3 times daily (Barker 2018; Finegold 1981) or 1 g 3 times daily (Prigogine 1988) for up to 14 days (Barker 2018; ERS [Polverino 2017]).

Cystitis, due to Enterococcus spp.: Note: Not recommended for empiric therapy given decreased efficacy compared to first-line agents and high prevalence of resistance (IDSA [Gupta 2011]).

Oral: 500 mg every 8 hours or 875 mg every 12 hours (Cole 2015; Hooton 2018; Swaminthan 2010)

Manufacturer's labeling: Dosing in the prescribing information may not reflect current clinical practice: Oral: 250 mg every 8 hours or 500 mg every 12 hours

Ear, nose, and throat infections:

Orbital cellulitis, uncomplicated (after response to parenteral treatment) or preseptal cellulitis: Oral: 875 mg every 12 hours as part of an appropriate combination regimen; dosing based on expert opinion (Gappy 2018a; Gappy 2018b)

Otitis media: Oral: 500 mg every 8 hours or 875 mg every 12 hours for 10 days (Limb 2018)

Note: Some experts recommend amoxicillin/clavulanate over amoxicillin alone for patients with severe otalgia, fever, or when there is concern for beta-lactamase-producing Haemophilus influenzae or Streptococcus pneumoniae with decreased penicillin susceptibility (Limb 2018; WHO 2001)

Streptococcal pharyngitis (group A): Oral: 1 g once daily or 500 mg twice daily for 10 days (AHA [Gerber 2009]; IDSA [Shulman 2012])

Extended release: 775 mg once daily for 10 days

Manufacturer's labeling. Dosing in the prescribing information may not reflect current clinical practice: Oral: 250 mg every 8 hours or 500 mg every 12 hours

Endocarditis, prophylaxis (dental or invasive respiratory tract procedures) (off-label use): Oral: 2 g 30 to 60 minutes before procedure. Note: Only recommended for patients with cardiac conditions associated with the highest risk of an adverse outcome from endocarditis and who are undergoing a procedure likely to result in bacteremia with an organism that has the potential ability to cause endocarditis.

Helicobacter pylori eradication: Oral:

Clarithromycin triple regimen: Amoxicillin 1 g 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%) (ACG [Chey 2017]; Fallone 2016).

Concomitant regimen: Amoxicillin 1 g 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 (ACG [Chey 2017])

Sequential regimen: Amoxicillin 1 g 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, plus a standard-dose proton pump inhibitor twice daily for 5 to 7 days; some experts prefer the 10-day sequential regimen (amoxicillin for 5 days followed by clarithromycin and metronidazole or tinidazole for 5 days) over the 14-day sequential regimen (amoxicillin for 7 days followed by clarithromycin and metronidazole or tinidazole for 7 days) due to the lack of data showing superiority over the 10-day regimen in North America (ACG [Chey 2017]; Crowe 2018).

Hybrid regimen: Amoxicillin 1 g twice daily, plus a standard-dose proton pump inhibitor twice daily for 7 days; then follow with amoxicillin 1 g 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 (ACG [Chey 2017]).

Levofloxacin triple regimen: Amoxicillin 1 g 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 (ACG [Chey 2017]).

Lyme disease (Borrelia spp. infection) (off-label use):

Early localized (eg, erythema migrans): Oral: 500 mg 3 times daily for 14 to 21 days (IDSA [Wormser 2006])

Early disseminated, carditis (mild [first-degree atrioventricular block with PR interval <300 msec] or stepdown therapy once PR interval <300 msec): Oral: 500 mg 3 times daily for 14 to 21 days (Hu 2018; IDSA [Wormser 2006]); some experts prefer a 21-day duration with initially mild cases or to complete a 21- to 28-day course with stepdown therapy for more severe carditis (Hu 2018).

Early disseminated, neurologic disease (isolated facial nerve palsy 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]).

Late disease, arthritis without neurologic involvement: Oral: 500 mg 3 times daily for 28 days (IDSA [Wormser 2006])

Late disease, acrodermatitis chronica atrophicans: Oral: 500 mg 3 times daily for 14 to 28 days (IDSA [Wormser 2006])

Periodontitis, generalized aggressive (off-label use): Oral: 250 to 500 mg every 8 hours in combination with metronidazole for 10 to 14 days; used in addition to scaling, root planing, and pocket irrigation (Rabelo 2015; Silva-Senem 2013; Wilder 2018)

Pneumonia, community-acquired:

Outpatient empiric therapy: Oral: 1 g 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 (IDSA/ATS [Mandell 2007])

Manufacturer's labeling: Dosing in the prescribing information may not reflect current clinical practice: Oral: 875 mg every 12 hours or 500 mg every 8 hours

Prosthetic joint infection (off-label use): Oral: 500 mg 3 times daily (IDSA [Osmon 2013]). Note: For chronic antimicrobial suppression of prosthetic joint infection caused by beta-hemolytic streptococci, penicillin-susceptible Enterococcus spp., or Cutibacterium spp.

Skin and soft tissue infection:

Cellulitis/erysipelas, mild:Oral: 875 mg twice daily or 500 mg 3 times daily for 5 to 10 days (duration should be extended if not resolved/slow response) (Spelman 2018; manufacturer's labeling). Note: Empiric MRSA coverage should be added for purulent infection (IDSA [Stevens 2014]; Spelman 2018).

Erysipeloid:Oral: 500 mg 3 times daily for 7 to 10 days (IDSA [Stevens 2014])

Manufacturer's labeling: Dosing in the prescribing information may not reflect current clinical practice: Oral: 500 mg every 12 hours or 250 mg every 8 hours

Dosing: Geriatric

Refer to adult dosing.

Dosing: Pediatric

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])

Indication-specific dosing:

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 (ISPD [Warady 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) (ISPD [Warady 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

Adults: Oral:

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)

Extended-release:

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:

Immediate-release:

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.

Reconstitution

Oral suspension: Refer to manufacturer's product labeling for reconstitution instructions. Shake vigorously.

Administration

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.

Dietary Considerations

Some products may contain phenylalanine.

Storage

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).

Drug Interactions

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

Test Interactions

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.

Adverse Reactions

1% to 10%:

Central nervous system: Headache (1%)

Gastrointestinal: Diarrhea (2%), nausea (1%), vomiting (1%)

Genitourinary: Vulvovaginal infection (2%)

Frequency not defined:

Cardiovascular: Hypersensitivity angiitis

Central nervous system: Agitation, anxiety, behavioral changes, confusion, dizziness, hyperactivity (reversible), insomnia, seizure

Dermatologic: Acute generalized exanthematous pustulosis, erythematous maculopapular rash, erythema multiforme, exfoliative dermatitis, skin rash, Stevens-Johnson syndrome, toxic epidermal necrolysis, urticaria

Gastrointestinal: Clostridioides (formerly Clostridium) difficile-associated diarrhea, Clostridioides (formerly Clostridium) difficile colitis, dental discoloration, hemorrhagic colitis, melanoglossia, mucocutaneous candidiasis

Genitourinary: Crystalluria

Hematologic & oncologic: Agranulocytosis, anemia, eosinophilia, hemolytic anemia, immune thrombocytopenia, leukopenia, thrombocytopenia

Hepatic: Cholestatic hepatitis, cholestatic jaundice, hepatitis (acute cytolytic), increased serum alanine aminotransferase, increased serum aspartate aminotransferase

Hypersensitivity: Anaphylaxis

Immunologic: Serum sickness-like reaction

<1%, postmarketing, and/or case reports: Abdominal pain

Warnings/Precautions

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.

Disease-related concerns:

• 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.

Monitoring Parameters

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

B

Pregnancy Considerations

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.

Patient Education

• 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.

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

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