amoxicillin 500 mg capsule

Uses

Amoxicillin shares the uses of other aminopenicillins and is used principally for the treatment of infections caused by susceptible gram-negative bacteria (e.g., Haemophilus influenzae, Escherichia coli, Proteus mirabilis, Salmonella). Amoxicillin also is used for the treatment of infections caused by susceptible gram-positive bacteria (e.g., Streptococcus pneumoniae, enterococci, nonpenicillinase-producing staphylococci, Listeria); however, like other aminopenicillins, amoxicillin generally should not be used for the treatment of streptococcal or staphylococcal infections when a natural penicillin would be effective.

Acute Otitis Media

Amoxicillin is used for the treatment of acute otitis media (AOM) caused by S. pneumoniae, H. influenzae, or M. catarrhalis. Amoxicillin usually is considered the drug of first choice for initial treatment of AOM, unless the patient has severe illness (moderate to severe otalgia or fever 39°C or higher) or the infection is suspected of being caused by β-lactamase-producing H. influenzae or M. catarrhalis, in which case amoxicillin and clavulanate potassium is recommended for initial treatment. The American Academy of Pediatrics (AAP), American Academy of Family Physicians (AAFP), US Centers for Disease Control and Prevention (CDC), and others state that, despite the increasing prevalence of multidrug-resistant S. pneumoniae and presence of β-lactamase-producing H. influenzae or M catarrhalis in many communities, amoxicillin remains the anti-infective of first choice for treatment of uncomplicated AOM since it is highly effective, has a narrow spectrum of activity, is well distributed into middle ear fluid, is well tolerated, has an acceptable taste, and is inexpensive. Amoxicillin (when given in a dosage of 80-90 mg/kg daily) usually is effective in the treatment of AOM caused by S. pneumoniae, including infections involving strains with intermediate resistance to penicillins, and also usually is effective in the treatment of AOM caused by most strains of H. influenzae.

Alternatives for initial treatment of AOM in patients with a history of non-type I hypersensitivity reactions to penicillins include oral cephalosporins (cefdinir, cefpodoxime, cefuroxime axetil) or parenteral ceftriaxone. Alternatives for patients with type I penicillin hypersensitivity include oral macrolides (azithromycin, clarithromycin, fixed combination of erythromycin and sulfisoxazole), oral co-trimoxazole, or oral clindamycin (especially in those with infections known or presumed to be caused by penicillin-resistant S. pneumoniae).

AAP, AAFP, and others recommend that patients who fail to respond to an initial amoxicillin regimen (given in a dosage of 80-90 mg/kg daily) within 48-72 hours should be retreated using a regimen of amoxicillin and clavulanate potassium (90 mg/kg of amoxicillin and 6.4 mg/kg of clavulanate daily in 2 divided doses). Alternatively, a 3-day regimen of IM or IV ceftriaxone can be used for retreatment in those who fail to respond to an initial amoxicillin regimen, especially in those who have severe illness (moderate to severe otalgia or fever 39°C or higher) and in those who are vomiting or cannot otherwise tolerate an oral regimen.

For additional information regarding treatment of AOM, including information on diagnosis and management strategies, anti-infectives for initial treatment, duration of initial treatment, and anti-infectives for retreatment and for information on current recommendations regarding management of otitis media with effusion (OME), .

Anthrax

Amoxicillin is used as an alternative agent for postexposure prophylaxis following exposure to Bacillus anthracis spores, for the treatment of anthrax when a parenteral regimen is not available (e.g., when there are supply or logistic problems because large numbers of individuals require treatment in a mass casualty setting), and for the treatment of cutaneous anthrax. Strains of B. anthracis with naturally occurring penicillin resistance have been reported rarely, and there are published reports of B. anthracis strains that have been engineered to have penicillin and tetracycline resistance as well as resistance to other anti-infectives (e.g., macrolides, chloramphenicol, rifampin). Therefore, it has been postulated that exposures to B. anthracis that occur in the context of biologic warfare or bioterrorism may involve bioengineered resistant strains and this concern should be considered when selecting initial therapy for the treatment of anthrax that occurs as the result of bioterrorism-related exposures or for postexposure prophylaxis following such exposures. For additional information on treatment of anthrax and recommendations for postexposure prophylaxis following exposure to anthrax spores,

Postexposure Prophylaxis

Ciprofloxacin or doxycycline generally are considered the initial drugs of choice for postexposure prophylaxis following suspected or confirmed exposure to aerosolized B. anthracis spores that occurs in the context of biologic warfare or bioterrorism. If exposure is confirmed and results of in vitro testing indicate that the organism is susceptible to penicillin, then postexposure prophylaxis may be switched to a penicillin (e.g., oral amoxicillin, oral penicillin V). IM penicillin G procaine also has been recommended as an alternative for postexposure prophylaxis. Although monotherapy with a penicillin is not recommended for the treatment of clinically apparent inhalational anthrax when high concentrations of the organism are likely to be present, penicillins may be considered an option for anti-infective prophylaxis when ciprofloxacin and doxycycline are contraindicated, since the likelihood of β-lactamase induction resulting in an increase in penicillin MICs is lower when only a small number of vegetative cells are present.

Although the CDC and other experts recommend that postexposure prophylaxis in children be initiated with ciprofloxacin or doxycycline, if exposure has been confirmed and in vitro tests indicate that the organism is susceptible to penicillin, the postexposure prophylaxis regimen in children may be switched to oral amoxicillin or oral penicillin V.

The possible benefits of postexposure prophylaxis against anthrax should be weighed against the possible risks to the fetus when choosing an anti-infective for postexposure prophylaxis in pregnant women. The CDC and other experts state that ciprofloxacin should be considered the drug of choice for initial postexposure prophylaxis in pregnant women exposed to B. anthracis spores and that, if in vitro studies indicate that the organism is susceptible to penicillin, then consideration can be given to changing the postexposure regimen to amoxicillin. Women who become pregnant while receiving anti-infective prophylaxis should continue the existing regimen and consult with a healthcare provider or public health official to discuss whether an alternative regimen might be more appropriate.

Cutaneous Anthrax

Although natural penicillins (e.g., oral penicillin V, IM penicillin G benzathine, IM penicillin G procaine) generally have been considered drugs of choice for the treatment of mild, uncomplicated cutaneous anthrax caused by susceptible strains of B. anthracis that occurs as the result of naturally occurring or endemic exposure to anthrax, the CDC recommends use of oral ciprofloxacin or oral doxycycline for the treatment of cutaneous anthrax that occurs following exposure to B. anthracis spores in the context of biologic warfare or bioterrorism. Therapy may be changed to oral amoxicillin if results of in vitro susceptibility testing indicate that the organism is susceptible to the drug and the patient is improving. Use of a multiple-drug parenteral regimen is recommended for the initial treatment of cutaneous anthrax when there are signs of systemic involvement, extensive edema, or lesions on the head and neck.

For young children (i.e., younger than 2 years of age), initial therapy for cutaneous anthrax should be IV rather than oral, and combination anti-infective therapy should be considered since it currently is not known whether infants and young children are at increased risk of systemic dissemination of cutaneous anthrax.

For more specific information on the uses of amoxicillin, see Uses in the Aminopenicillins General Statement 8:12.16.08.

For information on the uses of amoxicillin in fixed-ratio combinations with clavulanic acid, see Amoxicillin and Clavulanate Potassium 8:12.16.08.

Dosage and Administration

Reconstitution and Administration

Amoxicillin trihydrate is administered orally. Amoxicillin has also been given IV as the sodium salt, but a parenteral dosage form of amoxicillin is currently not available in the US.

Amoxicillin may be administered orally without regard to meals. However, in studies evaluating the film-coated tablet containing 875 mg of amoxicillin, the tablet was administered at the start of a light meal.

The required dose of reconstituted amoxicillin oral suspension should be placed directly on the child's tongue for swallowing. Alternatively, the required dose of oral suspension may be added to formula, milk, fruit juice, water, or ginger ale and then administered immediately.

Amoxicillin powder for oral suspension should be reconstituted at the time of dispensing by adding the amount of water specified on the bottle to provide a suspension containing 125, 200, 250, or 400 mg of amoxicillin per 5 mL or 50 mg of amoxicillin per mL. After tapping the bottle to thoroughly loosen the powder for oral suspension, the water should be added to the powder in 2 portions and the suspension agitated well after each addition. The suspension should be agitated well just prior to administration of each dose.

Dosage

Dosage of amoxicillin, which is available for oral use as the trihydrate, is expressed in terms of anhydrous amoxicillin.

General Adult Dosage

The usual adult dosage of amoxicillin for the treatment of mild to moderate infections of the ear, nose, or throat; skin and skin structure; or genitourinary tract is 500 mg every 12 hours or 250 mg every 8 hours. A dosage of 875 mg every 12 hours or 500 mg every 8 hours should be used for the treatment of severe infections of the ear, nose, or throat; skin and skin structure; or genitourinary tract in adults. The usual adult dosage of amoxicillin for the treatment of mild, moderate, or severe lower respiratory tract infections is 875 mg every 12 hours or 500 mg every 8 hours.

A single 3-g oral dose of amoxicillin has been used effectively for the initial treatment of acute, uncomplicated urinary tract infections in nonpregnant women.

General Pediatric Dosage

The manufacturer states that for neonates and infants 12 weeks of age or younger, amoxicillin may be administered in a dosage of up to 30 mg/kg daily in divided doses every 12 hours.

The usual dosage of amoxicillin for pediatric patients 3 months of age or older for the treatment of mild to moderate infections of the ear, nose, throat, skin and skin structure, or genitourinary tract is 20 mg/kg daily in divided doses every 8 hours or 25 mg/kg daily in divided doses every 12 hours. The usual dosage of amoxicillin for pediatric patients 3 months of age or older for the treatment of mild, moderate, or severe lower respiratory tract infections or for the treatment of severe infections of the ear, nose, throat, skin and skin structure, or genitourinary tract is 40 mg/kg daily in divided doses every 8 hours or 45 mg/kg daily in divided doses every 12 hours.

Acute Otitis Media

For the treatment of uncomplicated acute otitis media (AOM), the recommended dosage of amoxicillin is 80-90 mg/kg daily given in 2 or 3 divided doses. The drug usually is given for 10 days, but the optimal duration of therapy is uncertain. The American Academy of Pediatrics (AAP) and American Academy of Family Physicians (AAFP) recommend that a 10-day regimen be used for treatment of AOM in children younger than 6 years of age and in those with severe disease, but that a duration of 5-7 days may be appropriate in those 6 years of age or older with mild to moderate AOM.

Although amoxicillin has been given in a dosage of 40-45 mg/kg daily for 10 days for the treatment of AOM, the AAP, AAFP, US Centers for Disease Control and Prevention (CDC), and others recommend use of the higher amoxicillin dosage. The higher amoxicillin dosage (80-90 mg/kg daily) is especially important in patients with AOM known or suspected of being caused by Streptococcus pneumoniae with reduced susceptibility to penicillins and in patients with a history of anti-infective treatment of AOM within the previous few months.

Gonorrhea and Associated Infections

Some manufacturers state that adults and children weighing 40 kg or more may receive a single 3-g oral dose of amoxicillin for the treatment of acute, uncomplicated gonorrhea caused by susceptible nonpenicillinase-producing N. gonorrhoeae. and that children weighing less than 40 kg who are 2 years of age or older may receive a single 50-mg/kg (maximum 3 g) dose of oral amoxicillin given with a single 25-mg/kg (up to 1 g) oral dose of probenecid. However, penicillins are no longer included in CDC recommendations for the treatment of gonorrhea.

Chlamydial and Mycoplasmal Infections

For the treatment of chlamydial urogenital infections during pregnancy, the recommended dosage of oral amoxicillin is 500 mg 3 times daily for 7-10 days. Experience with oral amoxicillin therapy in this infection is limited and the drug may not be highly efficacious. Therefore, the CDC recommends that repeat testing (preferably by culture) should be performed 3 weeks after treatment is completed.

Lyme Disease

The Infectious Diseases Society of America (IDSA), AAP, and other clinicians consider amoxicillin a drug of choice for the treatment of early localized or early disseminated Lyme disease associated with erythema migrans, in the absence of neurologic involvement or third-degree atrioventricular (AV) heart block. Amoxicillin is preferred for the treatment of early Lyme disease in pregnant or lactating women and in children younger than 8 years of age.

For the treatment of mild Lyme carditis manifested by first- or second-degree AV heart block, amoxicillin 500 mg 3 times daily for 14-21 days is recommended in adults; children younger than 8 years of age should receive amoxicillin 50 mg/kg daily in 3 divided doses (maximum dose: 500 mg).

For the treatment of Lyme arthritis without associated neurologic disease, amoxicillin 500 mg 3 times daily for 28 days is recommended in adults; children should receive amoxicillin 50 mg/kg daily (maximum: 1.5 g daily). For the treatment of early localized or early disseminated Lyme disease associated with erythema migrans in adults, amoxicillin 500 mg 3 times daily for 14-21 days is recommended; children younger than 8 years of age should receive amoxicillin 50 mg/kg daily (maximum: 1.5 g daily) in 3 divided doses.

Helicobacter pylori Infection

For the treatment of Helicobacter pylori (formerly Campylobacter pylori or C. pyloridis) infection and duodenal ulcer disease (active or 1-year history of duodenal ulcer) in adults, the recommended dosage of amoxicillin is 1 g twice daily in combination with clarithromycin (500 mg twice daily) and lansoprazole (30 mg twice daily) for 14 days (triple therapy). When used in combination with clarithromycin (500 mg twice daily) and omeprazole (20 mg twice daily) for the treatment of H. pylori infection and duodenal ulcer disease (active or 1-year history of duodenal ulcer), the recommended dosage of amoxicillin is 1 g twice daily for 10 days (triple therapy). An additional 18 days of omeprazole monotherapy is recommended for ulcer healing and symptom relief in patients with an active duodenal ulcer at the time therapy is initiated.

For the treatment of H. pylori infection and duodenal ulcer disease (active or 1-year history of duodenal ulcer) in adults who are either allergic to or intolerant of clarithromycin or in whom resistance to clarithromycin is known or suspected, the recommended dosage of amoxicillin is 1 g 3 times daily in combination with lansoprazole 30 mg 3 times daily for 14 days (dual therapy).

When amoxicillin has been used in other multiple-drug regimens for the treatment of H. pylori infection and peptic ulcer disease in combination with at least one other agent that has activity against H. pylori, oral dosages of 500 mg 3 or 4 times daily (or 1 g 2 or 3 times daily) generally have been used; higher dosages of amoxicillin in such regimens reportedly have not been associated with improved results. Studies in which H. pylori was eradicated successfully generally have employed regimens consisting of a bismuth salt (e.g., bismuth subsalicylate), a nitroimidazole anti-infective (e.g., metronidazole), and another anti-infective agent (e.g., amoxicillin, tetracycline) or combined therapy with a proton-pump inhibitor (e.g., lansoprazole, omeprazole) and 1 or 2 anti-infective agents (e.g., clarithromycin, amoxicillin).

In a limited number of children with H. pylori-associated peptic ulcer disease (e.g., gastritis, duodenitis/ duodenal ulcer), oral amoxicillin 25-50 mg/kg daily in divided doses (e.g., 250-500 mg 3 times daily) has been administered as part of multiple-drug regimens that included a nitroimidazole anti-infective (e.g., metronidazole) and/or a bismuth salt (e.g., bismuth subsalicylate). Further study is needed to establish an optimal drug regimen for treatment of H. pylori infection in children.

Prevention of Bacterial Endocarditis

When selecting anti-infectives for the prevention of bacterial endocarditis, the current recommendations published by the American Heart Association (AHA) should be consulted.

When an oral regimen is used for prevention of bacterial endocarditis in patients at high or moderate risk undergoing certain dental procedures or minor upper respiratory tract surgery or instrumentation , the AHA, American Dental Association (ADA), and others currently recommend that adults receive a single 2-g dose of oral amoxicillin and children receive a single 50-mg/kg dose of oral amoxicillin given 1 hour prior to the procedure. Pediatric dosage should not exceed adult dosage. Previous recommendations for prophylaxis of bacterial endocarditis in patients undergoing dental or minor upper respiratory tract procedures included use of a 2-dose regimen of amoxicillin (3 g given 1 hour prior to the procedure and 1.5 g given 6 hours later). However, because recent comparisons of these dosing schedules indicate that a single 2-g dose of amoxicillin results in adequate serum concentrations for several hours and causes fewer adverse GI effects than the previously recommended regimen, recommended dosage was lowered and the second dose is no longer considered necessary.

For prevention of enterococcal endocarditis in patients at high or moderate risk undergoing certain GI, biliary tract, or genitourinary tract surgery or instrumentation , use of a 2-dose parenteral regimen is recommended for most patients; however, the AHA and others state that a single-dose regimen of parenteral ampicillin or oral amoxicillin can be considered for those with cardiac conditions that put them only at moderate risk of enterococcal endocarditis. If the single-dose amoxicillin regimen is used for prophylaxis of enterococcal endocarditis in patients at moderate risk, the AHA and others recommend that adults receive a single 2-g dose of oral amoxicillin and children receive a single 50-mg/kg dose of oral amoxicillin given 1 hour prior to the procedure. When a 2-dose regimen is used for prophylaxis of enterococcal endocarditis in patients at high or moderate risk, the first dose should consist of IM or IV ampicillin (2 g in adults or 50 mg/kg in children) given in conjunction with IM or IV gentamicin (1.5 mg/kg) and administered within 30 minutes of starting the procedure; the second dose administered 6 hours later can consist of IM or IV ampicillin (1 g in adults or 25 mg/kg in children) or, alternatively, oral amoxicillin (1 g in adults or 25 mg/kg in children). Pediatric dosage should not exceed adult dosage.

Anthrax

If oral amoxicillin is used as an alternative agent for postexposure prophylaxis following suspected or confirmed exposure to aerosolized anthrax spores (inhalational anthrax) or for the treatment of anthrax when a parenteral regimen is not available (e.g., when there are supply or logistic problems because large numbers of individuals require treatment in a mass casualty setting), the CDC and other experts (e.g., US Working Group on Civilian Biodefense) recommend that adults receive 500 mg 3 times daily and that children receive 80 mg/kg daily (maximum 1.5 mg daily) given in 3 divided doses at 8-hour intervals. Anti-infective postexposure prophylaxis should be continued until exposure to B. anthracis has been excluded. If exposure is confirmed, postexposure vaccination with anthrax vaccine (if available) may be indicated in conjunction with prophylaxis. Because of the possible persistence of anthrax spores in lung tissue following an aerosol exposure, the CDC and other experts recommend that postexposure prophylaxis be continued for 60 days.

If oral amoxicillin is used as an alternative for the treatment of mild, uncomplicated cutaneous anthrax caused by susceptible Bacillus anthracis, the CDC and other experts (e.g., US Working Group on Civilian Biodefense) recommend that adults receive 500 mg 3 times daily and that children receive 80 mg/kg daily (maximum 1.5 mg daily) given in 3 divided doses at 8-hour intervals. Cutaneous anthrax in infants and children younger than 2 years of age should be treated initially IV. Although 5-10 days of anti-infective therapy may be adequate for the treatment of mild, uncomplicated cutaneous anthrax that occurs as the result of natural or endemic exposures to anthrax, the CDC and other experts recommend that therapy be continued for 60 days if the cutaneous infection occurred as the result of exposure to aerosolized anthrax spores since the possibility of inhalational anthrax would also exist. Anti-infective therapy may limit the size of the cutaneous anthrax lesion and it usually becomes sterile within the first 24 hours of treatment, but the lesion will still progress through the black eschar stage despite effective treatment.

Duration of Therapy

The duration of amoxicillin therapy depends on the type and severity of infection and should be determined by the clinical and bacteriologic response of the patient. For most infections, except gonorrhea, therapy should be continued for at least 48-72 hours after the patient becomes asymptomatic or evidence of eradication of the infection has been obtained. Persistent infections may require several weeks of therapy. Amoxicillin usually is continued for 60 days for postexposure prophylaxis or treatment of inhalational or cutaneous anthrax in the context of biologic warfare or bioterrorism.

If amoxicillin is used in the treatment of infections caused by group A β-hemolytic streptococci, therapy should be continued for at least 10 days to decrease the risk of rheumatic fever and glomerulonephritis.

If amoxicillin is used in the treatment of chronic urinary tract infections, frequent bacteriologic and clinical appraisal is necessary during therapy and may be required for several months after therapy.

Dosage in Renal Impairment

In patients with renal impairment, doses and/or frequency of administration of amoxicillin should be modified in response to the degree of renal impairment, severity of the infection, and susceptibility of the causative organisms. The manufacturer states that adults with severe renal impairment and creatinine clearances less than 30 mL/minute should not receive the commercially available film-coated tablets containing 875 mg of amoxicillin. The recommended dosage of amoxicillin for adults with creatinine clearances of 10-30 mL/minute is 250 or 500 mg every 12 hours, depending on the severity of the infection, and the recommended dosage for adults with creatinine clearances less than 10 mL/minute is 250 or 500 mg every 24 hours, depending on the severity of the infection.

Patients undergoing hemodialysis should receive 250 or 500 mg of amoxicillin every 24 hours, depending on the severity of the infection, and should receive an additional dose of the drug during and after each dialysis period.

The manufacturer states that data are insufficient to recommend dosage for pediatric patients with renal impairment.

Cautions

Adverse Effects

Adverse effects reported with amoxicillin are similar to those reported with other aminopenicillins. For information on adverse effects reported with aminopenicillins,

Precautions and Contraindications

Amoxicillin shares the toxic potentials of the penicillins, including the risk of hypersensitivity reactions, and the usual precautions of penicillin therapy should be observed. Prior to initiation of therapy with amoxicillin, careful inquiry should be made concerning previous hypersensitivity reactions to penicillins, cephalosporins, or other allergens. There is clinical and laboratory evidence of partial cross-allergenicity among penicillins and other β-lactam antibiotics including cephalosporins and cephamycins. Amoxicillin is contraindicated in patients who are hypersensitive to any penicillin.

Because a high percentage of patients with infectious mononucleosis have developed rash during therapy with aminopenicillins, amoxicillin probably should not be used in patients with the disease.

Individuals with phenylketonuria (i.e., homozygous genetic deficiency of phenylalanine hydroxylase) and other individuals who must restrict their intake of phenylalanine should be warned that the amoxicillin 200- and 400-mg chewable tablets contain aspartame which is metabolized in the GI tract to provide 1.82 or 3.64 mg of phenylalanine, respectively, following oral administration. Amoxicillin powder for oral suspension does not contain aspartame.

Renal, hepatic, and hematologic systems should be evaluated periodically during prolonged therapy with amoxicillin.

For a more complete discussion of these and other precautions associated with the use of amoxicillin, .

Pregnancy and Lactation

Pregnancy

Safe use of amoxicillin during pregnancy has not been definitely established. There are no adequate or controlled studies using aminopenicillins in pregnant women, and amoxicillin should be used during pregnancy only when clearly needed. However, amoxicillin has been administered to pregnant women without evidence of adverse effects to the fetus. In addition, use of the drug is currently included in the US Centers For Disease Control and Prevention (CDC) recommendations for the treatment of chlamydial infections during pregnancy and CDC recommendations for the treatment of cutaneous anthrax or for postexposure prophylaxis following exposure to Bacillus anthracis spores.

Lactation

Because amoxicillin is distributed into milk and may lead to sensitization of infants, the drug should be used with caution in nursing women. Because of its general safety in infants, the CDC states that amoxicillin is an option for anti-infective prophylaxis in breast-feeding women when B. anthracis is known to be penicillin susceptible and there is no contraindication to maternal amoxicillin use.

Pharmacokinetics

For additional information on absorption of amoxicillin and for information on distribution and elimination of the drug,

Absorption

Amoxicillin is generally stable in the presence of acidic gastric secretions, and 74-92% of a single oral dose of the drug is absorbed from the GI tract. Amoxicillin is more completely absorbed from the GI tract than is ampicillin, and peak serum concentrations of amoxicillin are generally 2-2.5 times higher than those attained with an equivalent oral dose of ampicillin. As oral dosage of amoxicillin is increased, the fraction of the dose absorbed from the GI tract decreases only slightly and peak serum concentrations and areas under the serum concentration-time curves (AUCs) increase linearly with increasing dosage.

Peak serum concentrations are usually reached 1-2 hours after oral administration of amoxicillin capsules, film-coated tablets, chewable tablets, or oral suspension in fasting and nonfasting adults. Following oral administration of a single 250- or 500-mg dose of amoxicillin, peak serum concentrations range from 3.5-5 or 5.5-11 mcg/mL, respectively. In one study in healthy, fasting adults who received a single 500-mg oral dose of amoxicillin, serum concentrations of the drug averaged 3.3, 6.7, 9.3, 5.8, and 0.6 mcg/mL at 30 minutes, 1 hour, 2 hours, 3 hours, and 4 hours, respectively, after the dose. The manufacturer states that serum concentrations attained following administration of 125- or 250-mg chewable tablets are similar to those attained when the same dose is given as the oral suspension containing 125 or 250 mg of the drug per 5 mL. In healthy adults who received a single 400-mg dose of amoxicillin given as a 400-mg chewable tablet or the oral suspension containing 400 mg of the drug per 5 mL (dose given at the start of a light meal), peak serum concentrations were attained approximately 1 hour after the dose and averaged 5.18 or 5.92 mcg/mL, respectively, and AUC averaged 17.9 or 17.1 mcg&bul;hr/mL, respectively.

In one study in children 4-45 months of age receiving amoxicillin oral suspension in a dosage of 15 mg/kg daily, serum amoxicillin concentrations ranged from 2.4-8.5, 1.9-11.3, 1.7-6.4, 0.17-1.9, and 0.14-3.3 mcg/mL at 30 minutes, 1 hour, 2 hours, 4 hours, and 6 hours, respectively, after a dose.

Although presence of food in the GI tract reportedly results in lower and delayed peak serum concentrations of amoxicillin, the total amount of drug absorbed does not appear to be affected.