Brand Name(s): Amoxil, Moxatag, Trimox
Generic Name: amoxicillin
Drug Class: Pencillins
What Is Amoxicillin and How Does It Work?
Amoxicillin is a prescription antibiotic which is used to treat a wide variety of bacterial infections. This medication is a penicillin-type antibiotic. It works by stopping the growth of bacteria.
Amoxicillin treats only bacterial infections. It will not work for viral infections (such as common cold, flu). Unnecessary use or misuse of any antibiotic can lead to its decreased effectiveness.
Amoxicillin is also used with other medications to treat stomach/intestinal ulcers caused by the bacteria H. pylori and to prevent the ulcers from returning.
Amoxicillin is available under the following different brand names: Amoxil, Moxatag, and Trimox.
Dosages of Amoxicillin
Adult and pediatric dosages
Oral Solution
- 50 mg/5mL
- 125 mg/5mL
- 200 mg/5mL
- 250 mg/5mL
- 400 mg/5mL
- 250 mg
- 500 mg
- 500 mg
- 875 mg
Chewable Tablet
- 125 mg
- 250 mg
Extended-release (Moxatag)
- 775 mg
Dosage Considerations – Should be Given as Follows:
Adult Dosage Considerations
Ear, Nose, and Throat Infections
Mild to moderate infections
500 mg orally every 12 hours or 250 mg orally every 8 hours for 10-14 days
Severe infections
875 mg orally every 12 hours or 500 mg orally every 8 hours for 10-14 days
Moxatag: 775 mg orally once per day for 10 days, taken within 1 hour after finishing a meal
Genitourinary Tract Infections
Mild to moderate infections
500 mg orally every 12 hours or 250 mg orally every 8 hours
Severe infections
875 mg orally every 12 hours or 500 mg orally every 8 hours
Spectrum of action
E coli, P mirabilis, or E faecalis
Skin and Skin Structure Infections
Mild to moderate infections
500 mg orally every 12 hours or 250 mg orally every 8 hours
Severe infections
875 mg orally every 12 hours or 500 mg orally every 8 hours
Tonsillitis
775 mg (ER tablets) orally once per day for 10 days
Lower Respiratory Tract Infections
875 mg orally every 12 hours or 500 mg orally every 8 hours for 10-14 days
Helicobacter Pylori
H pylori infection and active or 1-year history of duodenal ulcer
Triple therapy
1 g orally every 12 hours for 14 days with lansoprazole (30 mg) and clarithromycin (500 mg)
Dual therapy
1 g orally every 8 hours for 14 days with lansoprazole (30 mg) in patients intolerant of, or resistant to, clarithromycin
Anthrax
Post exposure inhalational prophylaxis
500 mg orally every 8 hours
Infective Endocarditis
Prophylaxis
2 g orally 30-60 min before procedure
Dosing considerations
AHA guidelines recommend prophylaxis only in high-risk patients undergoing invasive procedures who have a history of cardiac conditions that predispose them to a risk of infection
Lyme Disease (Off-label)
Chronic migrating rash and other symptoms of early dissemination
500 mg orally every 8 hours (depending on size of patient) for 3-4 weeks
50 mg/kg/day every 8 hours in divided doses; maximum 500 mg/dose
Chlamydial Infection in Pregnant Women (Off-label)
First trimester: 500 mg orally every 8 hours for 7 days
Dosing considerations
First trimester: Test to document chlamydial eradication and retest for infection 3 months after treatment
Second or third trimester: Test to document chlamydial eradication
Limitation of Use
For use when susceptibility test results show susceptibility to amoxicillin, indicating no beta-lactamase production
Administration
Take without regard to meals
Dosing Modifications
Renal impairment: Patients with impaired renal function do not generally require dose reduction unless impairment is severe; do not administer extended-release product in patients with creatinine clearance under 30 mL/min
GFR under 30 mL/min: Should not receive 875 mg (immediate release) or 775 mg (extended release)
GFR 10-30 mL/min: 250-500 mg every 12 hours, depending on severity of infection
GFR under 10 mL/min: 250-500 mg every 24 hours depending on severity of infection
Hemodialysis patients: 250-500 mg every 24 hours, depending on severity of infection; patients should receive additional dose during and at completion of dialysis; do not administer extended-release product or 875 mg immediate release.
Pediatric Dosages Considerations:
Ear, Nose, and Throat Infections
Mild to moderate infections
Under 3 months: 30 mg/kg/day orally divided every 12 hours for 48-72 hours; for less than 10 days for S pyogenes infections
Older than 3 months and under 40 kg: 25 mg/kg/day orally divided every 12 hours or 20 mg/kg/day orally divided every 8 hours
Over 40 kg: 500 mg orally every 12 hours or 250 mg orally every 8 hours for 10-14 days
Severe infections
Under 3 months: 30 mg/kg/day orally divided every 12 hours for 48-72 hours; for less than 10 days for S pyogenes infections
Older than 3 months and less than 40 kg: 45 mg/kg/day orally divided every 12 hours or 40 mg/kg/day orally divided every 8 hours
Over 40 kg: 875 mg orally every12 hours or 500 mg orally every 8 hours for 10-14 days
Tonsillitis/Streptococcal pharyngitis
50 mg/kg orally every day for 10 days, not to exceed 1 g/day, orally 25 mg/kg orally twice daily for 10 days, not to exceed 500 mg/dose
Older than 12 years: 775 mg (Moxatag) orally once per day for 10 days, taken within 1 hour after meal (swallow tablet whole; do not crush or chew)
Acute Otitis Media
Older than 3 months and under 40kg: 80-90 mg/kg/day orally divided every 8-12 hours
Over 40 kg: 500 mg orally every 12 hours or 250 mg orally every 8 hours for 10-14 days
Lower Respiratory Tract Infections
Mild, moderate, or severe infections
Under 3 months: greater than or equal to 30 mg/kg/day orally divided every 12 hours for 48-72 hours; for less than 10 days for S pyogenes infections
Older than 3 months and under 40 kg: 45 mg/kg/day orally divided every 12hr or 40 mg/kg/day orally divided every 8 hours
Over 40kg: 875 mg orally every 12 hours or 500 mg orally every 8 hours for 10-14 days
Pneumonia, community-acquired (Off-label)
Since M. pneumoniae is the primary pathogen that causes pneumonia in patients 5-15 years old, a macrolide antibiotic may be a first choice treatment.
Under 3 months: Safety and efficacy not established
Older than 3 months:
Immediate release
Empiric treatment: 90 mg/kg/day orally divided every 12 hours for 10 days; not to exceed 4,000 mg/day
Group A Streptococcus: 50-75 mg/kg/day orally divided every 12 hours for 10 days; not to exceed 4,000 mg/day
H. influenza: 75-100 mg/kg/day orally divided every 8 hours for 10 days; not to exceed 4,000 mg/day
S. pneumoniae (mild infection or step-down therapy or when MICs to penicillin equal to or greater than 2.0 mcg/mL): 90 mg/kg/day orally divided every 12 hours or 45 mg/kg/day divided every 8 hours for 10 days; not to exceed 4,000 mg/day
Anthrax (Off-label)
Post exposure inhalational prophylaxis
Under 40 kg: 15 mg/kg orally every 8 hours (minimum recommended dose; should not be greater than 45 mg/kg/day or given less than every 8 hours
Over 40 kg: 500 mg orally every 8 hours
80 mg/kg/day orally divided every 8 hours for 4 weeks (with simultaneous vaccine) or for 60 days (without vaccine)
Infective Endocarditis (Off-label)
Prophylaxis
50 mg/kg orally 30-60 min before procedure
Dosing considerations
AHA guidelines recommend prophylaxis only in high-risk patients undergoing invasive procedures with history of cardiac conditions that predispose them to infection
Lyme Disease (Off-label)
Chronic migrating rash and other symptoms of early dissemination
Under 3 months: Safety and efficacy not established
Over 3 months and 40 kg: 25-50 mg/kg/day divided every 8 hours; not to exceed 500 mg.
Administration
Take without regard to meals.
Mixing oral suspension: Tap bottle until all powder flows freely; add approximately one third of the total amount of water for reconstitution and shake vigorously to wet powder; add remainder of water and shake vigorously again
After reconstitution, place required amount of suspension directly on child's tongue for swallowing; if taste is unacceptable, required amount of suspension can be added to formula, milk, fruit juice, water, ginger ale, or other cold drinks; preparation must be taken immediately.
Shake suspension well before using; any unused portion must be discarded after 14 days.

SLIDESHOW
Fungal Skin Infections: Types, Symptoms, and Treatments See SlideshowWhat Are Side Effects Associated with Using Amoxicillin?
Common side effects of amoxicillin include:
- acute allergic reaction
- anemia
- elevated liver enzymes
- persistent superficial infections of the skin
- diarrhea
- headache
- nausea
- vomiting
- rash
- antibiotic associated inflammation of the colon
- serum sickness-like reactions
Post marketing side effects of Amoxicillin reported include:
- persistent superficial infections of the skin
- gastrointestinal
- black hairy tongue
- hemorrhagic/pseudomembranous colitis (may occur during or after treatment)
- Hypersensitivity reactions
- liver dysfunction
- cholestatic jaundice
- hepatic cholestasis
- acute cytolytic hepatitis
- Renal (crystalluria)
- Anemia
- hemolytic anemia
- Low platelet count (thrombocytopenia)
- thrombocytopenic purpura
- eosinophilia
- Low white blood cell count (leukopenia)
- agranulocytosis
- Central nervous system reactions
- reversible hyperactivity
- agitation
- anxiety
- insomnia
- confusion
- convulsions
- behavioral changes
- dizziness
This document does not contain all possible side effects and others may occur. Check with your physician for additional information about side effects.
What Other Drugs Interact with Amoxicillin?
If your doctor has directed you to use this medication for diabetes, your doctor or pharmacist may already be aware of any possible drug interactions and may be monitoring you for them. Do not start, stop, or change the dosage of any medicine before checking with your doctor, health care provider or pharmacist first.
Severe Interactions of Amoxicillin include:
- none
Amoxicillin has moderate interactions with at least 27 different drugs.
Mild Interactions of Amoxicillin include:
- amiloride
- azithromycin
- aztreonam
- chloramphenicol
- clarithromycin
- erythromycin base
- erythromycin ethylsuccinate
- erythromycin lactobionate
- erythromycin stearate
- pyridoxine (antidote)
This document does not contain all possible interactions. Therefore, before using this product, tell your doctor or pharmacist of all the products you use. Keep a list of all your medications with you, and share the list with your doctor and pharmacist. Check with your physician if you have health questions or concerns.
What Are Warnings and Precautions for Amoxicillin?
Warnings
Documented hypersensitivity to penicillins, cephalosporins, and imipenem.
This medication contains amoxicillin. Do not take Amoxil, Moxatag, or Trimox, if you are allergic to amoxicillin or any ingredients contained in this drug.
Keep out of reach of children. In case of overdose, get medical help or contact a Poison Control Center immediately.
Contraindications
None.
Effects of Drug Abuse
None.
Short-Term Effects
See "What Are Side Effects Associated with Using Amoxicillin?"
Long-Term Effects
See "What Are Side Effects Associated with Using Amoxicillin?"
Cautions
Severe allergic reaction has been reported rarely but is more likely to occur following parenteral therapy with penicillins.
Clostridium difficile-associated diarrhea (CDAD) has been reported with use of nearly all antibacterial agents; severity may range from mild diarrhea to fatal colitis; CDAD may occur over 2 months after discontinuation of therapy; if CDAD is suspected or confirmed, discontinue immediately and begin appropriate fluid and electrolyte management, protein supplementation, antibiotic treatment of C difficile, and surgical evaluation.
Do not administer in patients with infectious mononucleosis or mono because of risk of development of red skin rash.
Do not administer to patients in the absence of a proven or suspected bacterial infection because of risk of development of drug-resistant bacteria.
Superinfections with bacterial or fungal pathogens may occur during therapy; if suspected, discontinue immediately and begin appropriate treatment.
Chewable tablets contain aspartame, which contains phenylalanine.
Use caution in patients with allergy to cephalosporins, carbapenems.
Endocarditis prophylaxis: use for only high-risk patients, as per recent AHA guidelines.
High doses may cause false urine glucose test by some methods
Pregnancy and Lactation
Use of amoxicillin in pregnancy may be acceptable. Either animal studies show no risk but human studies not available or animal studies showed minor risks and human studies done and showed no risk.
Amoxicillin is excreted in breast milk. Use with caution when lactating.

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Bowel regularity means a bowel movement every day. See AnswerFrom 
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