Medically reviewed on April 30, 2018.
Commonly used brand name(s)
In the U.S.
Available Dosage Forms:
Therapeutic Class: Antigout
Pharmacologic Class: Xanthine Oxidase Inhibitor
Uses For This Medicine
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.
Allopurinol is available only with your doctor's prescription.
Before Using This Medicine
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 allopurinol, the following should be considered:
Tell your doctor if you have ever had any unusual or allergic reaction to allopurinol 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.
|All Trimesters||C||Animal studies have shown an adverse effect and there are no adequate studies in pregnant women OR no animal studies have been conducted and there are no adequate studies in pregnant women.|
Studies in women suggest that this medication poses minimal risk to the infant when used during breastfeeding.
Interactions with Medicines
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 allopurinol, 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 allopurinol 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.
Using allopurinol 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.
Using allopurinol 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
Interactions with Food/Tobacco/Alcohol
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 allopurinol. 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 This Medicine
Take allopurinol 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 allopurinol after meals to avoid stomach upset.
Take allopurinol 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 allopurinol 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 allopurinol. 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.
- For treatment of gout:
If you miss a dose of allopurinol, 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.
Precautions While Using This Medicine
It is very important that your doctor check your or your child's progress at regular visits to make sure that allopurinol is working properly. Blood and urine tests may be needed to check for unwanted effects.
When you start using allopurinol, 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 allopurinol, 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.
Allopurinol may cause some people to become drowsy or less alert than they are normally. Make sure you know how you react to allopurinol 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.
This Medicine Side Effects
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
- Ankle, knee, or great toe joint pain
- joint stiffness or swelling
- rash with flat lesions or small raised lesions on the skin
- Abdominal or stomach pain
- ammonia-like breath odor
- bleeding gums
- blistering, peeling, or loosening of the skin
- blood in the urine or stools
- bloody nose
- bloody or black, tarry stools
- blue or pale skin
- changes in skin color
- chest pain or discomfort
- chest pain, possibly moving to the left arm, neck, or shoulder
- clay-colored stools
- cloudy urine
- cough or hoarseness
- coughing up blood
- cracks in the skin
- dark urine
- decreased urine output
- difficulty with breathing
- dry mouth
- feeling faint, dizzy, or lightheaded
- feeling of warmth or heat
- fever with or without chills
- flushing or redness of the skin, especially on the face and neck
- general feeling of discomfort or illness
- general feeling of tiredness or weakness
- incoherent speech
- increased urination
- joint or muscle pain
- large, flat, blue or purplish patches in the skin
- light-colored stools
- loss of appetite
- loss of heat from the body
- lower back or side pain
- metallic taste
- muscle twitching
- muscle weakness
- nausea or vomiting
- pain, tenderness, or swelling of the foot or leg
- painful or difficult urination
- pinpoint red or purple spots on the skin
- rapid weight gain
- red, irritated eyes
- red, swollen skin
- redness, soreness, or itching skin
- right upper abdominal or stomach pain and fullness
- scaly skin
- severe stomach pain
- shortness of breath
- slow or irregular heartbeat
- sore throat
- sores, ulcers, or white spots on the lips or in the mouth
- sores, welting, or blisters
- swelling of the face, ankles, hands, or lower legs
- swollen or painful glands
- swollen, painful, or tender lymph glands in the neck, armpit, or groin
- tightness in the chest
- unpleasant breath odor
- unusual bleeding or bruising
- unusual weight gain or loss
- vomiting of blood or material that looks like coffee grounds
- 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:Rare
- Bad, unusual, or unpleasant (after) taste
- blue-yellow color blindness
- blurred vision
- body aches or pain
- burning feeling in the chest or stomach
- burning, crawling, itching, numbness, prickling, "pins and needles", or tingling feelings
- burning, dry, or itching eyes
- burning, numbness, tingling, or painful sensations
- change in taste
- change in vision
- continuing ringing or buzzing or other unexplained noise in the ears
- decreased interest in sexual intercourse
- decreased vision
- difficulty with moving
- discharge or excessive tearing
- feeling of constant movement of self or surroundings
- hair loss or thinning of the hair
- hearing loss
- hives or welts
- impaired vision
- inability to have or keep an erection
- lack or loss of strength
- loss in sexual ability, desire, drive, or performance
- loss of appetite
- loss of memory
- multiple swollen and inflamed skin lesions
- muscle aching or cramping
- muscle pain or stiffness
- muscular pain, tenderness, wasting, or weakness
- noisy breathing
- problems with memory
- redness, pain, or swelling of the eye, eyelid, or inner lining of the eyelid
- runny nose
- sensation of spinning
- sensitivity to light
- sleepiness or unusual drowsiness
- stomach upset
- stuffy nose
- swelling of the breasts or breast soreness in both females and males
- swelling of the salivary glands
- swelling or inflammation of the mouth
- swollen joints
- tender, swollen glands in the neck
- tenderness in the stomach area
- throbbing pain
- tightness in the chest
- trouble getting pregnant
- trouble with sleeping
- trouble with swallowing
- unable to sleep
- unsteadiness or awkwardness
- voice changes
- weakness in the arms, hands, legs, or feet
- 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.
See also: Side effects (in more detail)
Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.
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- Drug class: antigout agents