Antibiotic Amoxicillin (Amoxil)

• Generic name: Amoxicillin
• Brand/Trade names: Amoxil, Trimox
• Dosages:
  Tablets, chewable 200 mg, 400 mg;
  Tablets 500 mg, 875 mg;
  Capsules 250 mg, 500 mg;
  Powder for oral suspension 125 mg per 5 mL; 200 mg per 5 mL ; 250 mg per 5 mL; 400 mg per 5 mL
• Pharmacologic category: Penicillin antibiotic
• Habit forming? No
• Pregnancy risk factor: B

Amoxicillin is a semisynthetic penicillin antibiotic of the aminopenicillin group. It is an analog of ampicillin.

Amoxicillin is indicated for the treatment of the infections caused by susceptible strains of specific organisms:

• Ear, nose, and throat infections - otitis media, pharyngitis, sinusitis, laryngitis and tonsillitis.
• Genitourinary tract infections - infections that affect the genital area (bacterial vaginisis) and urinary system (cystitis, pyelonephritis).
• Skin and skin structure infections - cellulitis (infection of the dermis and subcutaneous tissue), erysipelas (superficial form of cellulitis), folliculitis (inflammation of the hair follicles, if the infection of the follicle is deeper and involves more follicles, it moves into the furuncle and carbuncle), furuncles, carbuncles, abscesses, impetigo (large vessicles or honey-crusted sores), infected burns and other.
• Lower respiratory tract infections - bronchitis, pneumonia.
• Sexually transmitted diseases - gonorrhea.
• Helicobacter pylori infection - duodenal ulcer caused by H. pylori (in combination with clarithromycin and a PPI)

Common side effects of amoxicillin include an upset stomach, vomiting, and diarrhea. This is primarily due to the destruction of normal flora within the gastrointestinal tract. The most severe side effects include anaphylactic reaction, pseudomembranous colitis, leukopenia, and agranulocytosis.

• Absorption: Rapidly absorbed after oral administration
• Metabolism: Partially hepatic
• Elimination half-life: Elimination is primarily via the kidneys and is rapid, with a relatively short half-life of approximately 1 hour.
• Excretion: Approximately 60% excreted in the urine within 6 to 8 h as unchanged drug

• One of the safest antibiotics. Approved for use in neonates and children. Labeled as "Pregnancy category B".
• Amoxicillin offers an advantage over other panicillins (penicillin V, ampicillin) in that it is better absorbed from the gastrointestinal tract and because it provides higher and more prolonged blood antimicrobial levels.
• Amoxicillin has been extensively learned in many scientific studies.
• Amoxicillin diffuses into most body tissues and fluids, with the exception of brain and spinal fluid.
• Amoxicillin is indicated for a broad range of infections, and is commonly prescribed as a first-line therapy for common infections such as otitis media (middle ear infection), pharyngitis (sore throat), and sinusitis (sinus infection).
• Group A streptococcus, the bacteria causing strep throat, have been uniformly susceptible to amoxicillin and have not developed resistance to the penicillins, despite the long-term use of amoxicillin for pharyngitis.
• Inexpensive in comparison with many other antibiotics.
• Safe for use by pregnant women who are not allergic to penicillin.

• Not effective against beta-lactamase-producing organisms.
• There have been a rare cases of severe allergic reactions including angioneurotic oedema, anaphylaxis, serum sickness, hypersensitivity vasculitis and interstitial nephritis.
• Frequent gastrointestinal side effects, such as nausea, vomiting, and diarrhea.
• A recent study in the Archives of Pediatrics and Adolescent Medicine6 found the link between amoxicillin use during infancy and developmental enamel defects of permanent teeth. However, further research is needed.
• Laboratory test interactions. High urine concentrations of amoxicillin may result in false-positive reactions when testing for the presence of glucose in urine using CLINITEST®, Benedict’s Solution, or Fehling’s Solution.

• Chlamydial infections. Chlamydia is a common sexually transmitted disease (STD) caused by the bacterium, Chlamydia trachomatis, which can damage a woman's reproductive organs. Amoxicillin is a recommended treatment of Chlamydia Infection during pregnancy by Centers for Disease Control and Prevention5.
• Prophylaxis (prevention) of inhalational anthrax. Although the Centers for Disease Control and Prevention (CDC) considers ciprofloxacin and doxycycline as first line antibiotics, amoxicillin is also considered as an option in those patients where ciprofloxacin and doxycycline may be contraindicated2.
• Endocarditis. Amoxicillin is used for prevention of bacterial endocarditis. Endocarditis is a potentially life-threatening infection of the inner surface of the heart or the heart valves caused by bacteria usually found in the mouth, intestinal tract or urinary tract. When alpha-hemolytic streptococci are likely causes of endocarditis, the recommended standard prophylactic regimen is a single dose of oral amoxicillin.
• Lyme disease. Lyme disease is transmitted to people by ticks. According to treatment experts, antibiotic treatment for 3-4 weeks with amoxicillin (500 mg orally three times daily) is generally effective in early disease4.

Sore throat (bacterial pharyngitis) is caused by Streptococcus pyogenes, or group A beta-hemolytic streptococci. Strep throat is contagious and is spread by via the airborne route. The presence of strep bacteria can be confirmed with a throat culture.

Although strep infections are usually mild, and would often get better on their own, some untreated strep infections result in serious complications such as rheumatic fever (joint and heart disease) and post-streptococcal glomerulonephritis (inflammation of the kidneys).

Streptococcus pyogenes are highly susceptible to amoxicillin and have not developed resistance to the penicillins. Amoxicillin is superior to penicillin in the treatment of strep throat. In the US prospective observational study3 the elimination of strep throat symptoms was achieved in
84% of amoxicillin-treated children compared to 73% in the penicillin-treated children.

Amoxicillin is a bactericidal antibiotic (kill the bacteria). It inhibits (prevents) bacterial cell wall mucopeptide synthesis.

• Amoxicillin, Amoxil, Trimox Forum on Topix
• Amoxil (Amoxicillin) Reviews, Ratings by Patients on DrugLib.com
• Amoxicillin user reviews about treatment success rate on DailyStrength.org
• Amoxicillin User Reviews for bacterial infection, tonsillitis, pharyngitis, sinusitis, skin infection on Drugs.com
• Amoxicillin ratings on RevolutionHealth.com
• Amoxil (Amoxicillin) side effects:
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• Amoxicillin allergy? on MedHelp.org

• 1. U.S. Food and Drug Administration. Amoxicillin (Amoxil) U.S. Prescribing Information available at (PDF format)
• 2. Anthrax Treatment: Patient Information: Amoxicillin 500-mg Oral Capsules (Pills) Amoxicillin Oral Suspension. Centers for Disease Control and Prevention
• 3. Curtin-Wirt C, Casey JR, Murray PC, Cleary CT, Hoeger WJ, Marsocci SM, Murphy ML, Francis AB, Pichichero ME. Efficacy of penicillin vs. amoxicillin in children with group A beta hemolytic streptococcal tonsillopharyngitis. Clin Pediatr (Phila). 2003 Apr;42(3):219-25. SagePub
• 4. Luft BJ, Dattwyler RJ, Johnson RC, Luger SW, Bosler EM, Rahn DW, Masters EJ, Grunwaldt E, Gadgil SD. Azithromycin compared with amoxicillin in the treatment of erythema migrans. A double-blind, randomized, controlled trial. Annals Internal Medicine. 1996 May 1;124(9):785-91.
• 5. Sexually transmitted diseases treatment guidelines 2002. Centers for Disease Control and Prevention.
• 6. Hong L, Levy SM, Warren JJ, Dawson DV, Bergus GR, Wefel JS. Association of amoxicillin use during early childhood with developmental tooth enamel defects. Arch Pediatr Adolesc Med. 2005 Oct;159(10):943-8.