Dosage and administration

2 DOSAGE AND ADMINISTRATION In adults, 750 to 1750 mg/day in divided doses every 8 to 12 hours. In Pediatric Patients > 3 Months of Age, 20 to 45 mg/kg/day in divided doses every 8 to 12 hours. Refer to full prescribing information for specific dosing regimens. (2.1, 2.2, 2.3) The upper dose for neonates and infants ≤ 3 months is 30 mg/kg/day divided every 12 hours. (2.2) Dosing for H. pylori Infection: Triple therapy: 1 gram amoxicillin, 500 mg clarithromycin, and 30 mg lansoprazole, all given twice daily (every 12 hours) for 14 days. Dual therapy: 1 gram amoxicillin and 30 mg lansoprazole, each given three times daily (every 8 hours) for 14 days. (2.3) Reduce the dose in patients with severe renal impairment (GFR <30 mL/min). (2.4) 2.1 Dosing for Adult and Pediatric Patients > 3 Months of Age Treatment should be continued for a minimum of 48 to 72 hours beyond the time that the patient becomes asymptomatic or evidence of bacterial eradication has been obtained. It is recommended that there be at least 10 days’ treatment for any infection caused by Streptococcus pyogenes to prevent the occurrence of acute rheumatic fever. In some infections, therapy may be required for several weeks. It may be necessary to continue clinical and/or bacteriological follow-up for several months after cessation of therapy. Table 1. Dosing Recommendations for Adult and Pediatric Patients > 3 Months of Age a Dosing for infections caused by bacteria that are intermediate in their susceptibility to amoxicillin should follow the recommendations for severe infections. b The children’s dosage is intended for individuals whose weight is less than 40 kg. Children weighing 40 kg or more should be dosed according to the adult recommendations. Infection Severitya Usual Adult Dose Usual Dose for Children > 3 Monthsb Ear/Nose/Throat Skin/Skin Structure Genitourinary Tract Mild/Moderate 500 mg every 12 hours or 250 mg every 8 hours 25 mg/kg/day in divided doses every 12 hours or 20 mg/kg/day in divided doses every 8 hours Severe 875 mg every 12 hours or 500 mg every 8 hours 45 mg/kg/day in divided doses every 12 hours or 40 mg/kg/day in divided doses every 8 hours Lower Respiratory Tract Mild/Moderate or Severe 875 mg every 12 hours or 500 mg every 8 hours 45 mg/kg/day in divided doses every 12 hours or 40 mg/kg/day in divided doses every 8 hours 2.2 Dosing in Neonates and Infants Aged ≤ 12 Weeks (≤ 3 Months) Treatment should be continued for a minimum of 48 to 72 hours beyond the time that the patient becomes asymptomatic or evidence of bacterial eradication has been obtained. It is recommended that there be at least 10 days’ treatment for any infection caused by Streptococcus pyogenes to prevent the occurrence of acute rheumatic fever. Due to incompletely developed renal function affecting elimination of amoxicillin in this age group, the recommended upper dose of amoxicillin tablets is 30 mg/kg/day divided every 12 hours. There are currently no dosing recommendations for pediatric patients with impaired renal function. 2.3 Dosing for H. pylori Infection Triple therapy: The recommended adult oral dose is 1 gram amoxicillin, 500 mg clarithromycin, and 30 mg lansoprazole, all given twice daily (every 12 hours) for 14 days. Dual therapy: The recommended adult oral dose is 1 gram amoxicillin and 30 mg lansoprazole, each given three times daily (every 8 hours) for 14 days. Please refer to clarithromycin and lansoprazole full prescribing information. 2.4 Dosing in Renal Impairment Patients with impaired renal function do not generally require a reduction in dose unless the impairment is severe. Severely impaired patients with a glomerular filtration rate of < 30 mL/min should not receive a 875 mg dose. Patients with a glomerular filtration rate of 10 to 30 mL/min should receive 500 mg or 250 mg every 12 hours, depending on the severity of the infection. Patients with a glomerular filtration rate less than 10 mL/min should receive 500 mg or 250 mg every 24 hours, depending on severity of the infection. Hemodialysis patients should receive 500 mg or 250 mg every 24 hours, depending on severity of the infection. They should receive an additional dose both during and at the end of dialysis.

Pregnancy

8.1 Pregnancy Teratogenic Effects : Pregnancy Category B. Reproduction studies have been performed in mice and rats at doses up to 2000 mg/kg (3 and 6 times the 3 g human dose, based on body surface area). There was no evidence of harm to the fetus due to amoxicillin. There are, however, no adequate and well-controlled studies in pregnant women. Because animal reproduction studies are not always predictive of human response, amoxicillin should be used during pregnancy only if clearly needed.

Drug Interactions

7 DRUG INTERACTIONS Probenicid decreases renal tubular secretion of amoxicillin which may result in increased blood levels of amoxicillin. (7.1) Concomitant use of amoxicillin and oral anticoagulants may increase the prolongation of prothrombin time. (7.2) Coadministration with allopurinol increases the risk of rash. (7.3) Amoxicillin may reduce the efficacy of oral contraceptives. (7.4) 7.1 Probenecid Probenecid decreases the renal tubular secretion of amoxicillin. Concurrent use of amoxicillin and probenecid may result in increased and prolonged blood levels of amoxicillin. 7.2 Oral Anticoagulants Abnormal prolongation of prothrombin time (increased international normalized ratio [INR]) has been reported in patients receiving amoxicillin and oral anticoagulants. Appropriate monitoring should be undertaken when anticoagulants are prescribed concurrently. Adjustments in the dose of oral anticoagulants may be necessary to maintain the desired level of anticoagulation. 7.3 Allopurinol The concurrent administration of allopurinol and amoxicillin increases the incidence of rashes in patients receiving both drugs as compared to patients receiving amoxicillin alone. It is not known whether this potentiation of amoxicillin rashes is due to allopurinol or the hyperuricemia present in these patients. 7.4 Oral Contraceptives Amoxicillin may affect the gut flora, leading to lower estrogen reabsorption and reduced efficacy of combined oral estrogen/progesterone contraceptives. 7.5 Other Antibacterials Chloramphenicol, macrolides, sulfonamides, and tetracyclines may interfere with the bactericidal effects of penicillin. This has been demonstrated in vitro; however, the clinical significance of this interaction is not well documented. 7.6 Effects on Laboratory Tests High urine concentrations of ampicillin may result in false-positive reactions when testing for the presence of glucose in urine using CLINITEST®, Benedict’s Solution, or Fehling’s Solution. Since this effect may also occur with amoxicillin, it is recommended that glucose tests based on enzymatic glucose oxidase reactions (such as CLINISTIX®) be used. Following administration of ampicillin or amoxicillin to pregnant women, a transient decrease in plasma concentration of total conjugated estriol, estriol-glucuronide, conjugated estrone, and estradiol has been noted.

Indications And Usage

1 INDICATIONS AND USAGE Amoxicillin tablets are a penicillin-class antibacterial indicated for treatment of infections due to susceptible strains of designated microorganisms. Infections of the ear, nose, throat, genitourinary tract, skin and skin structure, and lower respiratory tract. (1.1 to 1.4) In combination for treatment of H. pylori infection and duodenal ulcer disease. (1.5) To reduce the development of drug-resistant bacteria and maintain the effectiveness of amoxicillin tablets and other antibacterial drugs, amoxicillin tablets should be used only to treat infections that are proven or strongly suspected to be caused by bacteria. (1.6) 1.1 Infections of the Ear, Nose, and Throat Amoxicillin tablets are indicated in the treatment of infections due to susceptible (ONLY β-lactamase-negative) isolates of Streptococcus species. (α- and β-hemolytic isolates only), Streptococcus pneumoniae, Staphylococcus spp., or Haemophilus influenzae. 1.2 Infections of the Genitourinary Tract Amoxicillin tablets are indicated in the treatment of infections due to susceptible (ONLY β-lactamase–negative) isolates of Escherichia coli, Proteus mirabilis, or Enterococcus faecalis. 1.3 Infections of the Skin and Skin Structure Amoxicillin tablets are indicated in the treatment of infections due to susceptible (ONLY β-lactamase–negative) isolates of Streptococcus spp. (α- and β-hemolytic isolates only), Staphylococcus spp., or E. coli. 1.4 Infections of the Lower Respiratory Tract Amoxicillin tablets are indicated in the treatment of infections due to susceptible (ONLY β-lactamase–negative) isolates of Streptococcus spp. (α- and β-hemolytic isolates only), S. pneumoniae, Staphylococcus spp., or H. influenzae. 1.5 Helicobacter pylori Infection Triple therapy for Helicobacter pylori with clarithromycin and lansoprazole: Amoxicillin tablets, in combination with clarithromycin plus lansoprazole as triple therapy, are indicated for the treatment of patients with H. pylori infection and duodenal ulcer disease (active or 1-year history of a duodenal ulcer) to eradicate H. pylori. Eradication of H. pylori has been shown to reduce the risk of duodenal ulcer recurrence. Dual therapy for H. pylori with lansoprazole: Amoxicillin tablets, in combination with lansoprazole delayed-release capsules as dual therapy, are indicated for the treatment of patients with H. pylori infection and duodenal ulcer disease (active or 1-year history of a duodenal ulcer) who are either allergic or intolerant to clarithromycin or in whom resistance to clarithromycin is known or suspected. (See the clarithromycin package insert, MICROBIOLOGY.) Eradication of H. pylori has been shown to reduce the risk of duodenal ulcer recurrence. 1.6 Usage To reduce the development of drug-resistant bacteria and maintain the effectiveness of amoxicillin tablets and other antibacterial drugs, amoxicillin tablets should be used only to treat infections that are proven or strongly suspected to be caused by bacteria. When culture and susceptibility information are available, they should be considered in selecting or modifying antibacterial therapy. In the absence of such data, local epidemiology and susceptibility patterns may contribute to the empiric selection of therapy.

Clinical Studies

14 CLINICAL STUDIES 14.1 H. pylori Eradication to Reduce the Risk of Duodenal Ulcer Recurrence Randomized, double-blind clinical studies performed in the United States in patients with H. pylori and duodenal ulcer disease (defined as an active ulcer or history of an ulcer within 1 year) evaluated the efficacy of lansoprazole in combination with amoxicillin capsules and clarithromycin tablets as triple 14-day therapy, or in combination with amoxicillin capsules as dual 14-day therapy, for the eradication of H. pylori. Based on the results of these studies, the safety and efficacy of 2 different eradication regimens were established: Triple therapy: Amoxicillin 1 gram twice daily/clarithromycin 500 mg twice daily/lansoprazole 30 mg twice daily (see Table 6). Dual therapy: Amoxicillin 1 gram three times daily/lansoprazole 30 mg three times daily (see Table 7). All treatments were for 14 days. H. pylori eradication was defined as 2 negative tests (culture and histology) at 4 to 6 weeks following the end of treatment. Triple therapy was shown to be more effective than all possible dual therapy combinations. Dual therapy was shown to be more effective than both monotherapies. Eradication of H. pylori has been shown to reduce the risk of duodenal ulcer recurrence. Table 6. H. pylori Eradication Rates When Amoxicillin is Administered as Part of a Triple Therapy Regimen Study Triple Therapy Triple Therapy Evaluable Analysisa [95% Confidence Interval] (number of patients) Intent-to-Treat Analysisb [95% Confidence Interval] (number of patients) Study 1 92 [80 - 97.7] (n = 48) 86 [73.3 - 93.5] (n = 55) Study 2 86 [75.7 - 93.6] (n = 66) 83 [72 - 90.8] (n = 70) a This analysis was based on evaluable patients with confirmed duodenal ulcer (active or within 1 year) and H. pylori infection at baseline defined as at least 2 of 3 positive endoscopic tests from CLOtest®, histology, and/or culture. Patients were included in the analysis if they completed the study. Additionally, if patients dropped out of the study due to an adverse event related to the study drug, they were included in the analysis as failures of therapy. b Patients were included in the analysis if they had documented H. pylori infection at baseline as defined above and had a confirmed duodenal ulcer (active or within 1 year). All dropouts were included as failures of therapy. Table 7. H. pylori Eradication Rates When Amoxicillin is Administered as Part of a Dual Therapy Regimen Study Dual Therapy Dual Therapy Evaluable Analysisa [95% Confidence Interval] (number of patients) Intent-to-Treat Analysisb [95% Confidence Interval] (number of patients) Study 1 77 [62.5 - 87.2] (n = 51) 70 [56.8 - 81.2] (n = 60) Study 2 66 [51.9 - 77.5] (n = 58) 61 [48.5 - 72.9] (n = 67) a This analysis was based on evaluable patients with confirmed duodenal ulcer (active or within 1 year) and H. pylori infection at baseline defined as at least 2 of 3 positive endoscopic tests from CLOtest®, histology, and/or culture. Patients were included in the analysis if they completed the study. Additionally, if patients dropped out of the study due to an adverse event related to the study drug, they were included in the analysis as failures of therapy. b Patients were included in the analysis if they had documented H. pylori infection at baseline as defined above and had a confirmed duodenal ulcer (active or within 1 year). All dropouts were included as failures of therapy.

Warnings And Cautions

5 WARNINGS AND PRECAUTIONS Anaphylactic reactions: Serious and occasionally fatal anaphylactic reactions have been reported in patients on penicillin therapy. Serious anaphylactic reactions require immediate emergency treatment with supportive measures. (5.1) Clostridium difficile -associated diarrhea (ranging from mild diarrhea to fatal colitis): Evaluate if diarrhea occurs. (5.2) 5.1 Anaphylactic Reactions Serious and occasionally fatal hypersensitivity (anaphylactic) reactions have been reported in patients on penicillin therapy including amoxicillin. Although anaphylaxis is more frequent following parenteral therapy, it has occurred in patients on oral penicillins. These reactions are more likely to occur in individuals with a history of penicillin hypersensitivity and/or a history of sensitivity to multiple allergens. There have been reports of individuals with a history of penicillin hypersensitivity who have experienced severe reactions when treated with cephalosporins. Before initiating therapy with amoxicillin, careful inquiry should be made regarding previous hypersensitivity reactions to penicillins, cephalosporins, or other allergens. If an allergic reaction occurs, amoxicillin should be discontinued and appropriate therapy instituted. 5.2 Clostridium difficile Associated Diarrhea Clostridium difficile associated diarrhea (CDAD) has been reported with use of nearly all antibacterial agents, including amoxicillin, and may range in severity from mild diarrhea to fatal colitis. Treatment with antibacterial agents alters the normal flora of the colon leading to overgrowth of C. difficile. C. difficile produces toxins A and B which contribute to the development of CDAD. Hypertoxin-producing strains of C. difficile cause increased morbidity and mortality, as these infections can be refractory to antimicrobial therapy and may require colectomy. CDAD must be considered in all patients who present with diarrhea following antibacterial use. Careful medical history is necessary since CDAD has been reported to occur over 2 months after the administration of antibacterial agents. If CDAD is suspected or confirmed, ongoing antibiotic use not directed against C. difficile may need to be discontinued. Appropriate fluid and electrolyte management, protein supplementation, antibiotic treatment of C. difficile, and surgical evaluation should be instituted as clinically indicated. 5.3 Development of Drug-Resistant Bacteria Prescribing amoxicillin in the absence of a proven or strongly suspected bacterial infection is unlikely to provide benefit to the patient and increases the risk of the development of drug-resistant bacteria. 5.4 Use in Patients With Mononucleosis A high percentage of patients with mononucleosis who receive amoxicillin develop an erythematous skin rash. Thus amoxicillin should not be administered to patients with mononucleosis.

Overdosage

Adverse Reactions

Recent major changes

Indications and Usage, Gonorrhea (1.5) Removed 9/2015 Dosage and Administration, Gonorrhea (2.1) Removed 9/2015

Mechanism

Contraindications

Nursing Mothers