Alopurinol - Use | Dose | Side Effects

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

Alopurinol is a drug that belongs to the group of inhibitors xanthine oxidase.

This medicine acts by blocking xanthine oxidase and prevents creation of urine acid. Accumulation of urine acid could cause a disease called gout. Precisely because it reduces creation of urine acid, It is used in the treatment of gout and in all conditions where there is an increased level of urine acid in the organism.

Urine acid increases the risk of kidney stone formation, therefore, this drug is used also to reduce kidney stone formation.


This medicament should not, or may be used, only with extra precautions in the following conditions:

  • If you are allergic to Alopurinol or some other similar drugs. Symptoms of an allergy include:
    1. rash,
    2. itching,
    3. redness,
    4. swelling of the face,
    5. swelling of the tongue,
    6. difficulty breathing. Anaphylactic shock may be caused by an allergy, resulting in death.
  • Kidney or liver disorders.
  • Diabetes.
  • If you have heart disorders (increased blood pressure, angina pectoris, heart insufficiency, and others).

Caution is warranted if you are under chemotherapy.

Alopurinol could cause agranulucytosis (reduced number of leucocytes). In such a case, your organism is susceptible to infections. Tell your doctor if you are experiencing flu-like symptoms:

  • Cough,
  • fiver,
  • sore throat,
  • nose leak. Avoid being near people who have a cold or any other infection.

It should not be used concomitant with alcoholic beverages, because the risk of side effects is increased.

Use during pregnancy and breastfeeding

According to the US Agency for Food and Drug Administration, Alopurinol belongs to the group C (FDA: Group C). This means that there are animal studies that have shown that this medicine is not harmful to the fetus, but there are no studies on humans. It should be used during pregnancy only if the benefit to the mother outweighs the risk to the child.

This medicine is passed from mother's blood into the milk and could harm your baby. Avoid breastfeeding while under Alopurinol therapy.

Use and Dose

Usual initial dose is Alopurinol 100 mg once a day. This dose can subsequently be increased up to 200-300 mg once a day.

If you are taking this drug in order to prevent formation of kidney stones, you should drink at least 9 glasses of water during the day.

Alopurinol should be taken with glass of water.

Do not use alcohol under any circumstances while using this drug.

Use with other medications (Interactions)

Alopurinol should not, or may be used, only with extra precautions with the following medications:

  • Oral anticoagulants used in the treatment of thrombosis, such as:
    • warfarin (Farin),
    • acenocoumarol (Sintrom, Sinkum 4). Concomitant use of Alopurinol with these medications increases the risk of bleeding.
  • Cyclosporine used in the treatment of autoimmune diseases
  • Medications used in the treatment of infections, so called antibiotics, such as penicillins
  • Medications used in the treatment of increased blood pressure, such as:
    • furosemide (Lasix),
    • spironolactone,
    • hydrochlorthiazide and others.

Tell your doctor about all medications and herbal preparations you are using.

Alopurinol side effects

Alopurinol may cause the following side effects:

  1. nausea,
  2. vomiting,
  3. diarrhea,
  4. stomachache,
  5. loss of appetite,
  6. loss of body weight,
  7. headache,
  8. sleepiness,
  9. kidney damage manifested as urinating disorder and painful urinating,
  10. flu-like symptoms (cough, fiver, sore throat, nose leak) and allergy.

Tell your doctor if you are experiencing any side effects.

Information on this website are provided for educational purposes only and are not intended for medical advice, diagnosis or treatment.

If you have any concerns or questions about your health, you should always consult with a physician or other health-care professional.

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