Alphamox - Dosage | Interactions | Effects

This article was medically reviewed by M.Pharm, Marko Tanaskovic on August 12, 2018. To read more about an author, click here.

Alphamox is a drug that as an active substance contains an antibiotic of the penicillin group called amoxicillin. It is used to treat a number of infections, including:

  • Upper respiratory tract infections
    • sinusitis
    • tonsillitis
    • nasopharyngitis
  • Lower respiratory infection (bronchitis and pneumonia)
  • Otitis media
  • Urinary tract infections (complicated and uncomplicated cystitis, pyelonephritis and uretretis)
  • Genital tract infection (gonorrhea)
  • Infection of serous membrane that lines the abdominal cavity
  • Prevention of endocarditis
  • Dental abscess
  • Typhoid and paratyphoid fever
  • Eradication of Helicobacter pylori

Alphamox is a broad spectrum antibiotic and works mainly on gram-positive bacteria (Staphylococci and Streptococci) and on a small number of gram-negative bacteria (Escherichia coli and Haemeophillus influenzae).

It is well absorbed after oral administration, and the highest concentration in the blood is achieved only few hours after oral administration. Food can affect the degree at which this medications is being absorbed, therefore it is recommended to take capsule one hour before or two hours after a meal.


Allergic reactions have been reported in less than 0.01% of the patients. Cross-sensitivity between penicillin and cephalosporin antibiotics has been established, and this drug should not be used in patients who are allergic to cephalosporins.

In a retrospective study that examined effects of this drug on 14717 patients, kidney damage were reported on five patients (0.03%). For this reason, this drug should be administered in smaller doses in patients who already have impaired renal function.

Patients who have infectious mononucleosis, may develop erythematous papular rash if they're using this medicine.

Caution should be exercised when this drug is administered simultaneously with anticoagulants, because it increases the risk of bleeding.

Alphamox, pregnancy and breastfeeding

AU TGA puts this drug in group B because there is insufficient data on the use of this drug during human pregnancy. Alphamox has not shown any teratogenic effects and, if necessary, can be used during pregnancy.

It can be used during breastfeeding, because except for the risk of sensitization, there are no data on other adverse effects on the infant.

Dosage instructions

Alphamox exists in the form of capsules at doses of 250 and 500 mg.

The usual dose in adult patients is 500 mg three times a day. The duration of therapy depends on the type and severity of infection.

The maximum daily dose of this drug is 6000 mg.

The recommended dosage follows in the table below:

Infection Recommended dose
Gonorrhea Only a single dose of 3000 mg
Uncomplicated urinary tract infections and tooth abscess Two doses of 3000 mg (the interval between the dose should be about 12 hours)
Eradication of Helicobacter pylori 1000 mg twice a day in combination with omeprazole and clarithromycin
Prevention endocarditis 2000 mg taken one hour prior to the procedure
Otitis media 500 mg every 8 hours for 10-14 days
Upper respiratory tract infections 500 mg every 8 hours for 7-10 days

In patients with creatinine clearance of 10-30 ml / min, the dose should be reduced by 30%, while in patients with creatinine clearance less than 10 mL / min, the dose should be reduced by 65%.

The dosage in children should be calculated on the basis of body weight.


The only clinically significant interaction which may have serious consequences for the health is with the drug called methotrexate (a drug used for the treatment of cancer and autoimmune disease). Alphamox can increase plasma levels of methotrexate, which increases the risk of side effects of methotrexate.

Adverse effects

Alphamox may cause the following adverse effects:

  • Prolonged bleeding time
  • Excess movements (hyperkinesia)
  • Seizures
  • Fungal infections which affect the oral mucosa
  • Reduction in the number of leukocytes and platelets in the blood
  • Nausea and vomiting
  • Crystalluria in patients with decreased urine output
  • Allergic reactions


  1. NCBI link 1

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