Amoxicillin Uses, Dosage, Side Effects, Food Interaction and all others data.

Amoxycillin is a semi-synthetic antibiotic, an analog of ampicillin, with a broad spectrum of bactericidal activity against many gram-positive and gram-negative microorganisms. Amoxycillin is bactericidal against susceptible organisms during the stage of active multiplication. It acts through the inhibition of biosynthesis of cell wall mucopeptides.

Amoxicillin competitively inhibit penicillin binding proteins, leading to upregulation of autolytic enzymes and inhibition of cell wall synthesis. Amoxicillin has a long duration of action as it is usually given twice daily. Amoxicillin has a wide therapeutic range as mild overdoses are not associated with significant toxicity. Patients should be counselled regarding the risk of anaphylaxis, Clostridium difficile infections, and bacterial resistance.

Trade Name Amoxicillin
Availability Prescription only
Generic Amoxicillin
Amoxicillin Other Names Amox, Amoxicilina, Amoxicillin, Amoxicilline, Amoxicillinum, Amoxycillin, p-Hydroxyampicillin
Related Drugs prednisone, omeprazole, albuterol, pantoprazole, doxycycline, ciprofloxacin, cephalexin, metronidazole, azithromycin, clindamycin
Weight 250mg, 500mg, 125mg/5ml, , 500mg + 500mg + 30mg, 500mg + 500mg + 20mg, 250mg + 10mg + 12.5mg
Type Capsule, Suspension, Oral Kit, Oral Delayed Release Capsule, Oral, Injection Powder, Tablet For Oral Suspension
Formula C16H19N3O5S
Weight Average: 365.404
Monoisotopic: 365.104541423
Protein binding

Amoxicillin is 17% protein bound in serum.

Groups Approved, Vet approved
Therapeutic Class Broad spectrum penicillins
Manufacturer Euro Pharma International, Sigma Pharmaceuticals Plc (special Concept Development, Rxfarma), Phapros, Infion, Bernofarm, Sanbe, Baroque Pharmaceuticals Pvt Ltd
Available Country Pakistan, United Kingdom, United States, Indonesia, India, Nigeria
Last Updated: September 19, 2023 at 7:00 am


Amoxicillin is used for the treatment of the following bacterial infections when caused by susceptible organisms:

  • Respiratory tract, ENT infections: Acute and chronic bronchitis, pneumonia, otitis media, sinusitis, tonsillitis, pharyngitis & laryngitis, lobar & bronchopneumonia, chronic bronchial sepsis.
  • Urinary tract infections: Pyelonephritis, cystitis and urethritis.
  • Obstetric & gynaecological infections: Bacteriuria in pregnancy, septic abortion, intra-abdominal sepsis and puerperal sepsis.
  • Gastro-intestinal infections: Typhoid and paratyphoid.
  • Skin & soft tissue infections: Cellulitis, infected wounds and abscesses.
  • Generalized infections: Septicemia, bacterial endocarditis, meningitis, peritonitis and osteomyelitis.
  • Venereal infections: Gonorrhea and syphilis. Amoxicillin may also be used as prophylactic cover for patients at risk of developing endocarditis when undergoing dental surgery.

Amoxicillin is also used to associated treatment for these conditions: Acute Bacterial Sinusitis (ABS), Acute Otitis Media, Acute Otitis Media (AOM), Bacterial Infections, Community Acquired Pneumonia (CAP), Duodenal ulcer caused by helicobacter pylori, Genitourinary infections, Helicobacter Pylori Infection, Lower Respiratory Tract Infection (LRTI), Peptic Ulcer With H. Pylori Infection, Sinusitis, Skin and Subcutaneous Tissue Bacterial Infections, Urinary Tract Infection, Acute, uncomplicated Gonorrhea, Ear, nose, and throat infections

How Amoxicillin works

Amoxicillin competitively inhibits penicillin-binding protein 1 and other high molecular weight penicillin binding proteins. Penicillin bind proteins are responsible for glycosyltransferase and transpeptidase reactions that lead to cross-linking of D-alanine and D-aspartic acid in bacterial cell walls. Without the action of penicillin binding proteins, bacteria upregulate autolytic enzymes and are unable to build and repair the cell wall, leading to bacteriocidal action.


Amoxicillin dosage

Ear/Nose/ThroatInfection (Mild to Moderate):

  • Adult:500 mg every 12 hours or 250 mg every 8 hours
  • Children:25 mg/kg/day in divided doses every 12 hours or 20 mg/kg/day in divided doses every 8 hours

Ear/Nose/ThroatInfection (Severe):

  • Adult: 875 mg every 12 hours or 500 mg every 8 hours
  • Children: 45 mg/kg/day in divided doses every 12 hours or 40 mg/kg/day in divided doses every 8 hours

Lower respiratory tractInfection (Mild/ Moderate/Severe):

  • Adult: 875 mg every 12 hours or 500 mg every 8 hours
  • Children: 45 mg/kg/day in divided doses every 12 hours or 40 mg/kg/day in divided doses every 8 hours

Skin/skin structureInfection (Mild/Moderate):

  • Adult: 500 mg every 12 hours or 250 mg every 8 hours
  • Children: 25 mg/kg/day in divided doses every 12 hours or 20 mg/kg/day in divided doses every 8 hours

Skin/skin structureInfection (Severe):

  • Adult: 875 mg every 12 hours or 500 mg every 8 hours
  • Children: 45 mg/kg/day in divided doses every 12 hours or 40 mg/kg/day in divided doses every 8 hours

Genitourinary tractInfection (Mild/ Moderate):

  • Adult: 500 mg every 12 hours or 250 mg every 8 hours
  • Children: 25 mg/kg/day in divided doses every 12 hours or 20 mg/kg/day in divided doses every 8 hours

Genitourinary tractInfection (Severe):

  • Adult: 875 mg every 12 hours or 500 mg every 8 hours
  • Children: 45 mg/kg/day in divided doses every 12 hours or 40 mg/kg/day in divided doses every 8 hours

Gonorrhea, Acute, uncomplicated ano-genital, and urethral infections in males and females:

  • Adult: 3 g as single oral dose
  • Prepubertal children: 50 mg/Kg/Amoxycillin, combined with 25 mg/kg Probenecid as a single dose. Since Probenecid is contraindicated in children under 2 years, do not use this regimen in these cases.

Suspension: Shake the bottle well before adding water. Then add 12 tea spoonful (60 ml) of boiled and cooled water to the bottle and shake well to make 100 ml suspension.

Amoxycillin 500 mg Injection:

  • Intramuscular : Add 2.5 ml water for injection to Amoxycillin 500 mg injection vial.
  • Intravenous : Dissolve Amoxycillin 500 mg injection in 10 ml water for injection.

Side Effects

Side effects are mild, rare and infrequent. As with other penicillins, it may induce diarrhea, indigestion or skin rashes that usually stop during treatment and rarely calls for discontinuation of therapy.


Patients experiencing an overdose may present with hematuria, oliguria, abdominal pain, acute renal failure, vomiting, diarrhea, rash, hyperactivity, and drowsiness. Treat overdose with symptomatic and supportive treatment, which may include emesis or hemodialysis.


In renal impairment, the excretion of antibiotic will be delayed and depending on the degree of impairment it may be necessary to reduce the total daily dose.


The simultaneous use of Amoxicillin and an oral contraceptive might cause breakthrough bleeding or pregnancy on rare occasions. Concurrent administration of probenecid delays the excretion of Amoxicillin.

Food Interaction

  • Take with food.

Volume of Distribution

The central volume of distribution of amoxicillin is 27.7L.

Elimination Route

Amoxicillin is approximately 60% bioavailable. A 250mg dose of oral amoxicillin reaches a Cmax 3.93±1.13mg/L with a Tmax 1.31±0.33h and an AUC of 27.29±4.72mg*h/L. A 875mg dose of oral amoxicillin reaches a Cmax 11.21±3.42mg/L with a Tmax 1.52±0.40h and an AUC of 55.04±12.68mg*h/L.

Half Life

The half life of amoxicillin is 61.3 minutes.


The mean clearance of amoxicillin is 21.3L/h.

Elimination Route

125mg to 1g doses of amoxicillin are 70-78% eliminated in the urine after 6 hours.

Pregnancy & Breastfeeding use

Because of its lack of teratogenicity, Amoxicillin can beused safely throughout pregnancy at the normal adult dose. The small amount of Amoxicillin secreted in maternal milk rarely causes problem in the infant. It can therefore be used safely during lactation in most instances.


Amoxicillin is contraindicated for patients hypersensitive to penicillin, infectious mononucleosis, neonatal period or babies born of mothers hypersensitive to penicillin

Acute Overdose

If encountered, gastro-intestinal symptoms and disturbance of the fluid and electrolyte balance may be evident. They may be treated symptomatically and supportive with attention to the water/ electrolyte balance. In the absence of an adequate fluid intake and urinary output, crystalluria is a possibility and the antibiotic may be removed from the circulation by haemodialysis. Oral administration can cause gastro intestinal symptoms such as transient diarrhoea, nausea and colic which are dose related and a result of local irritation not toxicity.

Storage Condition

Store in a cool & dry place protected from light. Amoxicillin suspension and drops should be freshly prepared, stored in a cool dry place preferably in a refrigerator. Reconstituted suspension and drops should be used within 5 days if kept at room temperature or within 7 days if kept in a refrigerator.

Innovators Monograph

You find simplified version here Amoxicillin

Amoxicillin contains Amoxicillin see full prescribing information from innovator Amoxicillin Monograph, Amoxicillin MSDS, Amoxicillin FDA label


What is Amoxicillin used for?

Amoxicillin is used to treat bacterial infections, such as chest infectionsand dental abscesses.

How safe is Amoxicillin?

Amoxicillin is a safe and affordable antibiotic; however, it is not the right antibiotic for all infections. It is important not to share your antibiotics with anyone. An antibiotic is prescribed specifically for you and your particular type of bacterial infection.

How does Amoxicillin work?

Amoxicillin work by binding proteins and inhibiting certain processes in bacterial cells.

What are the common side effects of Amoxicillin?

The most common side effects of Amoxicillin are feeling sick and diarrhoea. Liquid Amoxicillin can stain your teeth. This does not last and is removed by brushing. You can drink alcohol while taking Amoxicillin.

Is Amoxicillin safe during pregnancy?

Amoxicillin is in the penicillin family of antibiotics. Some antibiotics are safe to take during pregnancy, while others are not.Amoxicillin is considered a pregnancy category B drug by the U.S. Food and Drug Administration. That means it’s considered safe to take while pregnant. it's considered safe to take while pregnant.

Is Amoxicillin safe during breastfeeding?

Amoxicillin is used to treat infections in babies and it can be used by women who are breastfeeding.Amoxicillin passes into breast milk and although this is unlikely to have any harmful effects on a nursing infant, it could theoretically affect the natural bacteria found in the baby's mouth or gut.

Can I drink alcohol with Amoxicillin?

Yes, you can drink alcohol while taking the antibiotic Amoxicillin. The alcohol will not stop Amoxicillin from working. However, many health professionals will recommend you avoid alcohol to give your body the best chance possible to fight the infection.

Can I drive after taking Amoxicillin ?

Amoxicillin can have side effects and the symptoms may make you unfit to drive. Do not drive or operate machinery unless you are feeling well.

When should be taken of Amoxicillin?

Amoxicillin is usually taken every 12 hours or every 8 hours with or without food. The length of your treatment depends on the type of infection that you have. Take Amoxicillin at around the same times every day.

Should Amoxicillin be taken on an empty stomach?

Take this medicine by mouth with a glass of water. Follow the directions on your prescription label.You can take it with or without food. If it upsets your stomach, take it with food.

Can I take Amoxicillin once a day?

Amoxicillin is ideal for once-daily dosing due to its low cost.

How long should Amoxicillin take to work?

Amoxicillin begins to work quickly after a patient takes it, and it reaches peak blood concentrations in about one or two hours, according to the drug's label. However, improvement in symptoms will take longer.

How long do Amoxicillin stay in my system?

After taking an oral dose of Amoxicillin, 60% of it will be out of your system in 6 to 8 hours.

Can I take Amoxicillin for a long time?

A person may take antibiotics for a long time for severe or continued infections, such as osteomyelitis. Doing so puts them at higher risk of long-term complications , including crystalluria, hemolytic anemia, and nephritis.

How long can I take Amoxicillin?

Amoxicillin also depends on the type of infection you're treating. Most antibiotics should be taken for 7 to 14 days.

How should not take Amoxicillin?

You should not use Amoxicillin if you are allergic to any penicillin antibiotic, such as Amoxicillin.

What happens if I miss a dose of Amoxicillin?

Skip the missed dose and use your next dose at the regular time. Do not use two doses at one time.

Can Amoxicillin effects my fertility?

Antibiotics affect both the quantity and quality of sperm. They may reduce the number of sperm a man produces, and make the sperm he does produce swim more slowly.

What happen if I overdose on Amoxicillin?

Antibiotic overdoses are rarely dangerous, but stomach upset and diarrhea may occur. Taking the wrong antibiotic is a problem if someone is allergic to the drug.

Does Amoxicillin make sleepy?

If you're taking prescription Amoxicillin, you may feel tired and fatigued.

Can I take Amoxicillin before bed?

It is generally not a good idea to take these medications right before bedtime.

Do Amoxicillin weaken my immune system?

Very rarely, antibiotic treatment will cause a drop in the blood count, including the numbers of white cells that fight infection. This corrects itself when the treatment is stopped.

Do Amoxicillin affect the liver?

Amoxicillin are a common cause of drug-induced liver injury.

*** Taking medicines without doctor's advice can cause long-term problems.