Amoxicillin

Description

Amoxicillin capsules, USP are a semisynthetic antibacterial agent, specifically amoxicillin, which is an analog of ampicillin. This drug exhibits a broad spectrum of bactericidal activity against various Gram-positive and Gram-negative microorganisms. The chemical structure of amoxicillin is defined as (2S,5R,6R)-6-((R)-(-)-2-amino-2-(p-hydroxyphenyl)acetamido-3,3-dimethyl-7-oxo-4-thia-1-azabicyclo3.2.0heptane-2-carboxylic acid trihydrate. The molecular formula for amoxicillin is C16H19N3O5S•3H2O, with a molecular weight of 419.45. Each capsule, characterized by a blue cap and pink body, contains either 250 mg or 500 mg of amoxicillin USP as the trihydrate. Inactive ingredients include D&C Red No. 28, FD&C Blue No. 1, FD&C Red No. 40, gelatin, magnesium stearate, microcrystalline cellulose, sodium lauryl sulfate, and titanium dioxide.

Uses and Indications

Amoxicillin capsules are indicated for the treatment of infections caused by susceptible strains of designated microorganisms. This medication is specifically indicated for the following conditions:

• Upper Respiratory Tract Infections of the Ear, Nose, and Throat

• Infections of the Genitourinary Tract

• Infections of the Skin and Skin Structure

• Infections of the Lower Respiratory Tract

• Helicobacter pylori Infection and Duodenal Ulcer Disease (for adult patients only)

Amoxicillin capsules should be utilized exclusively for the treatment or prevention of infections that are proven or strongly suspected to be bacterial in origin. This approach is essential to reduce the development of drug-resistant bacteria and to maintain the effectiveness of amoxicillin capsules and other antibacterial agents.

Dosage and Administration

In adults, the recommended dosage ranges from 750 mg to 1750 mg per day, administered in divided doses every 8 to 12 hours. For pediatric patients over 3 months of age, the dosage is 20 mg to 45 mg per kg per day, also given in divided doses every 8 to 12 hours. Healthcare professionals should refer to the full prescribing information for specific dosing regimens tailored to individual patient needs.

For neonates and infants aged 3 months or younger, the upper limit of dosing is 30 mg per kg per day, divided and administered every 12 hours.

In the treatment of H. pylori infection in adults, two therapeutic regimens are recommended. The triple therapy consists of 1 gram of amoxicillin, 500 mg of clarithromycin, and 30 mg of lansoprazole, all administered twice daily (every 12 hours) for a duration of 14 days. Alternatively, the dual therapy includes 1 gram of amoxicillin and 30 mg of lansoprazole, each given three times daily (every 8 hours) for 14 days.

It is essential to reduce the dosage in patients with severe renal impairment, specifically in those with a glomerular filtration rate (GFR) greater than 30 mL/min.

Contraindications

Use is contraindicated in patients with a history of serious hypersensitivity reactions, including anaphylaxis or Stevens-Johnson syndrome, to amoxicillin capsules or other beta-lactam antibiotics, such as penicillins or cephalosporins. This contraindication is due to the potential for severe allergic reactions in these individuals.

Warnings and Precautions

Serious and occasionally fatal anaphylactic reactions have been reported in patients receiving penicillin therapy, including amoxicillin. It is imperative that healthcare professionals remain vigilant for signs of anaphylaxis. Should any allergic reaction occur, amoxicillin must be discontinued immediately.

Severe cutaneous adverse reactions (SCAR) have also been associated with amoxicillin use. Patients should be monitored closely for the development of rashes, and if any rash progresses, amoxicillin should be discontinued to prevent further complications.

Additionally, drug-induced enterocolitis syndrome (DIES) has been documented in patients taking amoxicillin. In the event that DIES is suspected, it is crucial to discontinue amoxicillin and initiate appropriate therapeutic measures.

Clostridioides difficile-associated diarrhea (CDAD) can manifest in a spectrum ranging from mild diarrhea to severe, potentially fatal colitis. Healthcare professionals should evaluate any patient presenting with diarrhea during or after treatment with amoxicillin, as timely intervention may be necessary.

Side Effects

Patients receiving amoxicillin may experience a range of adverse reactions, which can be categorized into common and serious reactions.

Common adverse reactions include diarrhea, rash, vomiting, and nausea. These reactions are frequently observed in clinical settings and should be monitored.

Serious adverse reactions necessitate immediate attention and may require discontinuation of therapy. Anaphylactic reactions, which can be serious and occasionally fatal, have been reported in patients undergoing penicillin therapy, including amoxicillin. If an anaphylactic reaction occurs, amoxicillin should be discontinued promptly. Additionally, severe cutaneous adverse reactions (SCAR) have been noted; patients should be monitored closely, and treatment should be stopped if a rash progresses. Drug-induced enterocolitis syndrome (DIES) has also been associated with amoxicillin use, and if this condition arises, amoxicillin should be discontinued, and appropriate therapy should be initiated. Clostridioides difficile-associated diarrhea (CDAD) can range from mild diarrhea to severe, potentially fatal colitis, and should be evaluated if diarrhea occurs.

It is important to note that patients with a history of serious hypersensitivity reactions, such as anaphylaxis or Stevens-Johnson syndrome, to amoxicillin capsules or other beta-lactams (including penicillins or cephalosporins) may be at increased risk for adverse reactions.

Overdosage of amoxicillin has been associated with interstitial nephritis, which can result in oliguric renal failure, as reported in a small number of patients. Crystalluria has also been documented, with some cases leading to renal failure in both adult and pediatric patients following overdosage.

Drug Interactions

Co-administration of amoxicillin with probenicid is not recommended due to potential interactions that may affect the pharmacokinetics of amoxicillin.

When amoxicillin is used concurrently with oral anticoagulants, there is an increased risk of prolongation of prothrombin time. Clinicians should monitor prothrombin time closely and consider dosage adjustments of the anticoagulant as necessary.

The concomitant use of amoxicillin and allopurinol has been associated with an increased risk of rash. Patients should be monitored for dermatological reactions, and if a rash occurs, discontinuation of one or both medications may be warranted.

Additionally, amoxicillin may reduce the efficacy of oral contraceptives. Patients using oral contraceptives should be advised to consider alternative or additional contraceptive methods during treatment with amoxicillin.

Packaging & NDC

The table below lists all NDC Code configurations of Amoxicillin, the U.S. brand-name prescription product. Columns show Packaging, Formulation Type, and Active Ingredient Strength.

Pediatric Use

The safety and effectiveness of amoxicillin have been established for the treatment of upper respiratory tract infections, as well as infections of the genitourinary tract, skin and skin structure, and lower respiratory tract in pediatric patients. However, the safety and effectiveness of amoxicillin for the treatment of H. pylori infection have not been established in this population.

In pediatric patients aged 12 weeks or younger (3 months or younger), caution is advised due to incompletely developed renal function, which may delay the elimination of amoxicillin. Therefore, dosing should be modified accordingly in this age group to ensure safety and efficacy.

Geriatric Use

An analysis of clinical studies of amoxicillin has been conducted to evaluate the response of subjects aged 65 and over compared to younger subjects. The findings from these analyses did not identify significant differences in responses between elderly patients and their younger counterparts; however, it is important to note that a greater sensitivity to the drug in some older individuals cannot be ruled out.

Amoxicillin is substantially excreted by the kidneys, which raises concerns regarding the risk of toxic reactions, particularly in patients with impaired renal function. Given that elderly patients are more likely to experience decreased renal function, careful consideration should be given to dose selection in this population. It may be beneficial to monitor renal function in geriatric patients to ensure safe and effective use of the medication.

Pregnancy

Amoxicillin is classified as Pregnancy Category B. Reproduction studies conducted in mice and rats at doses up to 2000 mg/kg, which is 3 and 6 times the human dose of 3 g based on body surface area, have shown no evidence of harm to the fetus. However, there are no adequate and well-controlled studies in pregnant women.

Due to the limitations of animal reproduction studies in predicting human response, amoxicillin should be used during pregnancy only if clearly needed. Healthcare professionals are advised to weigh the potential benefits against any possible risks when considering the use of amoxicillin in pregnant patients.

Lactation

Penicillins, including amoxicillin, have been shown to be excreted in human milk. The use of amoxicillin by nursing mothers may lead to sensitization of breastfed infants. Therefore, caution should be exercised when administering amoxicillin to lactating mothers.

Renal Impairment

Patients with renal impairment have not been specifically addressed in the available data regarding dosage adjustments, special monitoring, or safety considerations. Therefore, healthcare professionals should exercise caution when prescribing this medication to patients with reduced kidney function, as the lack of information necessitates careful clinical judgment and monitoring.

Hepatic Impairment

Patients with hepatic impairment have not been specifically studied in relation to the use of this medication. Consequently, there are no established dosage adjustments, special monitoring requirements, or precautions outlined for individuals with compromised liver function. It is recommended that healthcare providers exercise caution when prescribing this medication to patients with hepatic impairment, given the lack of data on its safety and efficacy in this population. Regular monitoring of liver function may be prudent in these cases, although specific parameters are not defined in the available information.

Overdosage

In the event of amoxicillin overdosage, it is imperative to discontinue the medication immediately and implement symptomatic treatment alongside supportive measures as necessary.

Clinical observations from a prospective study indicate that overdosages of amoxicillin below 250 mg/kg typically do not result in significant clinical symptoms. However, it is essential to monitor patients closely, as there have been reports of interstitial nephritis leading to oliguric renal failure in a small subset of individuals following overdosage. Additionally, crystalluria has been documented, which in some instances has progressed to renal failure in both adult and pediatric populations.

To mitigate the risk of crystalluria associated with amoxicillin overdosage, maintaining adequate fluid intake and promoting diuresis are crucial. This approach helps to ensure proper renal function and reduces the likelihood of complications. It is noteworthy that renal impairment observed in these cases appears to be reversible upon cessation of amoxicillin administration.

Patients with pre-existing renal impairment may experience elevated blood levels of amoxicillin due to decreased renal clearance, necessitating careful monitoring and management. In cases of severe overdosage, hemodialysis may be employed as a method to facilitate the removal of amoxicillin from the bloodstream.

Healthcare professionals should remain vigilant in assessing and managing potential symptoms and complications associated with amoxicillin overdosage to ensure optimal patient outcomes.

Nonclinical Toxicology

Long-term studies in animals have not been performed to evaluate the carcinogenic potential of the compound. While specific studies to detect the mutagenic potential of amoxicillin alone have not been conducted, data from tests on a 4:1 mixture of amoxicillin and potassium clavulanate provide relevant insights.

The combination of amoxicillin and potassium clavulanate was found to be non-mutagenic in both the Ames bacterial mutation assay and the yeast gene conversion assay. However, it exhibited a weakly positive response in the mouse lymphoma assay, where the observed trend toward increased mutation frequencies occurred at doses that were also associated with decreased cell survival. In contrast, the mixture was negative in the mouse micronucleus test and in the dominant lethal assay in mice.

Potassium clavulanate alone was evaluated in the Ames bacterial mutation assay and the mouse micronucleus test, yielding negative results in both assays.

In a multi-generation reproduction study conducted in rats, no impairment of fertility or other adverse reproductive effects were observed at doses up to 500 mg/kg, which is approximately twice the human dose of 3 g based on body surface area.

Postmarketing Experience

No specific postmarketing experience details are available in the extracted data. As such, there are no additional adverse events or rare case reports to summarize.

Patient Counseling

Healthcare providers should advise patients that amoxicillin may be taken every 8 hours or every 12 hours, depending on the prescribed dosage. It is important to counsel patients that amoxicillin is a penicillin class drug, which can cause allergic reactions in some individuals.

Patients should be informed about the signs and symptoms of serious skin manifestations. They should be instructed to stop taking amoxicillin immediately and promptly report any signs or symptoms of skin rash, mucosal lesions, or other indications of hypersensitivity.

Additionally, healthcare providers should counsel patients that diarrhea is a common side effect associated with antibacterial drugs, typically resolving upon discontinuation of the medication. However, patients should be made aware that they may develop watery and bloody stools (with or without stomach cramps and fever) even as late as 2 months after their last dose of the antibacterial drug. If such symptoms occur, patients should contact their physician as soon as possible.

It is essential to inform patients that antibacterial drugs, including amoxicillin, are intended solely for the treatment or prevention of bacterial infections and do not address viral infections, such as the common cold. When prescribed amoxicillin for a bacterial infection, patients should be reminded that it is common to feel better early in the treatment course, but the medication must be taken exactly as directed. Skipping doses or failing to complete the full course of therapy may decrease the effectiveness of the immediate treatment and increase the likelihood of bacteria developing resistance, rendering amoxicillin or other antibacterial drugs ineffective in the future.

Storage and Handling

The product is supplied in a tight container to ensure integrity and stability. It should be stored at a temperature range of 20° to 25°C (68° to 77°F), with permissible excursions between 15° to 30°C (59° to 86°F) as defined by USP Controlled Room Temperature guidelines.

Additional Clinical Information

No further data are available.

FDA Insert (PDF)

This document is the official FDA-approved prescribing information for Amoxicillin as submitted by QPharma Inc. It includes detailed information about indications, dosage, contraindications, warnings, and clinical pharmacology.

View full prescribing information (PDF)