Allopurinol (Oral Route)

    Allopurinol (Oral Route)


    Description and Brand Names of Allopurinol (Oral Route)

    US Brand Name

    1. Zyloprim


    Allopurinol is used to prevent or treat high uric acid levels in the blood. Gout or gouty arthritis (inflammation and pain in a joint) is caused by high uric acid levels. Allopurinol is a xanthine oxidase inhibitor that works by causing less uric acid to be produced by the body.

    Allopurinol is also used to prevent or treat high uric acid levels that may be caused by cancer medicines or for patients with kidney stones that contain calcium.

    This medicine is available only with your doctor’s prescription.

    This product is available in the following dosage forms:

    • Capsule
    • Tablet

    Before Using Allopurinol (Oral Route)

    In deciding to use a medicine, the risks of taking the medicine must be weighed against the good it will do. This is a decision you and your doctor will make. For this medicine, the following should be considered:


    Tell your doctor if you have ever had any unusual or allergic reaction to this medicine or any other medicines. Also tell your health care professional if you have any other types of allergies, such as to foods, dyes, preservatives, or animals. For non-prescription products, read the label or package ingredients carefully.


    Appropriate studies performed to date have not demonstrated pediatric-specific problems that would limit the usefulness of allopurinol in children with high uric acid levels caused by cancer.


    No information is available on the relationship of age to the effects of allopurinol in geriatric patients.



    Studies in women suggest that this medication poses minimal risk to the infant when used during breastfeeding.

    Drug Interactions

    Although certain medicines should not be used together at all, in other cases two different medicines may be used together even if an interaction might occur. In these cases, your doctor may want to change the dose, or other precautions may be necessary. When you are taking this medicine, it is especially important that your healthcare professional know if you are taking any of the medicines listed below. The following interactions have been selected on the basis of their potential significance and are not necessarily all-inclusive.

    Using this medicine with any of the following medicines is not recommended. Your doctor may decide not to treat you with this medication or change some of the other medicines you take.

    • Didanosine

    Using this medicine with any of the following medicines is usually not recommended, but may be required in some cases. If both medicines are prescribed together, your doctor may change the dose or how often you use one or both of the medicines.

    • Azathioprine
    • Captopril
    • Cyclophosphamide
    • Enalapril
    • Enalaprilat
    • Mercaptopurine
    • Pegloticase
    • Tegafur

    Using this medicine with any of the following medicines may cause an increased risk of certain side effects, but using both drugs may be the best treatment for you. If both medicines are prescribed together, your doctor may change the dose or how often you use one or both of the medicines.

    • Aluminum Hydroxide
    • Cyclosporine
    • Phenprocoumon
    • Vidarabine
    • Warfarin

    Other Interactions

    Certain medicines should not be used at or around the time of eating food or eating certain types of food since interactions may occur. Using alcohol or tobacco with certain medicines may also cause interactions to occur. Discuss with your healthcare professional the use of your medicine with food, alcohol, or tobacco.

    Other Medical Problems

    The presence of other medical problems may affect the use of this medicine. Make sure you tell your doctor if you have any other medical problems, especially:

    • Bone marrow problems or
    • Liver disease – Use with caution. May make these conditions worse.
    • Kidney disease – Use with caution. The effects may be increased because of slower removal of the medicine from the body.

    Proper Use of Allopurinol (Oral Route)

    Take this medicine exactly as directed by your doctor. Do not take more of it, do not take it more often, and do not take it for a longer time than your doctor ordered. To do so may increase the chance of side effects.

    Take this medicine after meals to avoid stomach upset.

    Take this medicine with plenty of liquids to help prevent kidney stones. Check with your doctor about the amount of liquid you or your child should drink each day.


    The dose of this medicine will be different for different patients. Follow your doctor’s orders or the directions on the label. The following information includes only the average doses of this medicine. If your dose is different, do not change it unless your doctor tells you to do so.

    The amount of medicine that you take depends on the strength of the medicine. Also, the number of doses you take each day, the time allowed between doses, and the length of time you take the medicine depend on the medical problem for which you are using the medicine.

    • For oral dosage form (tablets):

      • For treatment of gout:

        • Adults – At first, 100 to 300 milligrams (mg) per day, taken once a day or in divided doses. Your doctor may adjust your dose as needed. However, the dose is usually not more than 800 mg per day.
        • Children – Use and dose must be determined by your doctor.
      • For treatment of high uric acid levels caused by cancer medicines:

        • Adults, teenagers, and children 11 years of age and older – 600 to 800 milligrams (mg) per day, taken in divided doses for 2 to 3 days.
        • Children 6 to 10 years of age – 300 mg per day, taken once a day for 2 to 3 days.
        • Children younger than 6 years of age – 150 mg per day, taken once a day for 2 to 3 days.
      • For treatment of kidney stones:

        • Adults – 200 to 300 milligrams (mg) per day, taken once a day or in divided doses. Your doctor may adjust your dose as needed. However, the dose is usually not more than 800 mg per day.
        • Children – Use and dose must be determined by your doctor.

    Missed Dose

    If you miss a dose of this medicine, take it as soon as possible. However, if it is almost time for your next dose, skip the missed dose and go back to your regular dosing schedule. Do not double doses.


    Store the medicine in a closed container at room temperature, away from heat, moisture, and direct light. Keep from freezing.

    Keep out of the reach of children.

    Do not keep outdated medicine or medicine no longer needed.

    Ask your healthcare professional how you should dispose of any medicine you do not use.


    It is very important that your doctor check your or your child’s progress at regular visits to make sure that this medicine is working properly. Blood and urine tests may be needed to check for unwanted effects.

    When you start using this medicine, you may have more gout attacks. Keep using the medicine even if this happens. Your doctor may give you other medicines (eg, colchicine or pain medicines [NSAIDs]) to help prevent the gout attacks.

    If you or your child develop a skin rash, hives, swelling of the lips or mouth, or any allergic reaction to this medicine, stop taking the medicine and call your doctor right away.

    Check with your doctor right away if you or your child have pain or tenderness in the upper stomach; pale stools; dark urine; loss of appetite; nausea; unusual tiredness or weakness; or yellow eyes or skin. These could be symptoms of a serious liver problem.

    This medicine may cause some people to become drowsy or less alert than they are normally. Make sure you know how you react to this medicine before you drive, use machines, or do anything else that could be dangerous if you are not alert.

    Do not take other medicines unless they have been discussed with your doctor. This includes prescription or nonprescription (over-the-counter [OTC]) medicines and herbal or vitamin supplements.

    Side Effects of Allopurinol (Oral Route)

    Along with its needed effects, a medicine may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

    Check with your doctor immediately if any of the following side effects occur:

    More common

    1. Ankle, knee, or great toe joint pain
    2. joint stiffness or swelling
    3. rash
    4. rash with flat lesions or small raised lesions on the skin


    1. Abdominal or stomach pain
    2. agitation
    3. ammonia-like breath odor
    4. anxiety
    5. bleeding gums
    6. blistering, peeling, or loosening of the skin
    7. blood in the urine or stools
    8. bloody nose
    9. bloody or black, tarry stools
    10. blue or pale skin
    11. bruising
    12. changes in skin color
    13. chest pain or discomfort
    14. chest pain, possibly moving to the left arm, neck, or shoulder
    15. chills
    16. clay-colored stools
    17. cloudy urine
    18. coma
    19. confusion
    20. constipation
    21. cough or hoarseness
    22. coughing up blood
    23. cracks in the skin
    24. dark urine
    25. decreased urine output
    26. depression
    27. diarrhea
    28. difficulty with breathing
    29. dizziness
    30. drowsiness
    31. dry mouth
    32. feeling faint, dizzy, or lightheaded
    33. feeling of warmth or heat
    34. fever
    35. fever with or without chills
    36. flushing or redness of the skin, especially on the face and neck
    37. general feeling of discomfort or illness
    38. general feeling of tiredness or weakness
    39. headache
    40. hostility
    41. incoherent speech
    42. increased urination
    43. irritability
    44. itching
    45. joint or muscle pain
    46. large, flat, blue or purplish patches in the skin
    47. lethargy
    48. light-colored stools
    49. loss of appetite
    50. loss of heat from the body
    51. lower back or side pain
    52. metallic taste
    53. muscle twitching
    54. muscle weakness
    55. nausea or vomiting
    56. pain, tenderness, or swelling of the foot or leg
    57. painful or difficult urination
    58. pinpoint red or purple spots on the skin
    59. rapid weight gain
    60. rash
    61. red, irritated eyes
    62. red, swollen skin
    63. redness, soreness, or itching skin
    64. right upper abdominal or stomach pain and fullness
    65. scaly skin
    66. seizures
    67. severe stomach pain
    68. shortness of breath
    69. slow or irregular heartbeat
    70. sore throat
    71. sores, ulcers, or white spots on the lips or in the mouth
    72. sores, welting, or blisters
    73. stupor
    74. sweating
    75. swelling of the face, ankles, hands, or lower legs
    76. swollen or painful glands
    77. swollen, painful, or tender lymph glands in the neck, armpit, or groin
    78. thirst
    79. tightness in the chest
    80. unpleasant breath odor
    81. unusual bleeding or bruising
    82. unusual weight gain or loss
    83. vomiting of blood or material that looks like coffee grounds
    84. wheezing
    85. yellow eyes or skin

    Some side effects may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects. Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:


    1. Bad, unusual, or unpleasant (after) taste
    2. blindness
    3. blue-yellow color blindness
    4. blurred vision
    5. body aches or pain
    6. burning feeling in the chest or stomach
    7. burning, crawling, itching, numbness, prickling, “pins and needles”, or tingling feelings
    8. burning, dry, or itching eyes
    9. burning, numbness, tingling, or painful sensations
    10. change in taste
    11. change in vision
    12. congestion
    13. continuing ringing or buzzing or other unexplained noise in the ears
    14. decreased interest in sexual intercourse
    15. decreased vision
    16. difficulty with moving
    17. discharge or excessive tearing
    18. feeling of constant movement of self or surroundings
    19. hair loss or thinning of the hair
    20. hearing loss
    21. hives or welts
    22. impaired vision
    23. inability to have or keep an erection
    24. indigestion
    25. lack or loss of strength
    26. loss in sexual ability, desire, drive, or performance
    27. loss of appetite
    28. loss of memory
    29. multiple swollen and inflamed skin lesions
    30. muscle aching or cramping
    31. muscle pain or stiffness
    32. muscular pain, tenderness, wasting, or weakness
    33. noisy breathing
    34. problems with memory
    35. redness, pain, or swelling of the eye, eyelid, or inner lining of the eyelid
    36. runny nose
    37. sensation of spinning
    38. sensitivity to light
    39. sleepiness or unusual drowsiness
    40. sleeplessness
    41. sneezing
    42. stomach upset
    43. stuffy nose
    44. sweating
    45. swelling of the breasts or breast soreness in both females and males
    46. swelling of the salivary glands
    47. swelling or inflammation of the mouth
    48. swollen joints
    49. tearing
    50. tender, swollen glands in the neck
    51. tenderness in the stomach area
    52. throbbing pain
    53. tightness in the chest
    54. trouble getting pregnant
    55. trouble with sleeping
    56. trouble with swallowing
    57. unable to sleep
    58. unsteadiness or awkwardness
    59. voice changes
    60. weakness in the arms, hands, legs, or feet
    61. weight loss

    Other side effects not listed may also occur in some patients. If you notice any other effects, check with your healthcare professional.

    Call your doctor for medical advice about side effects. You may report side effects to the FDA at 1-800-FDA-1088.