Proper Use
If this medicine upsets your stomach, it may be taken after meals. If stomach upset (indigestion, nausea, vomiting, diarrhea, or stomach pain) continues, check with your doctor.
In order for this medicine to help you, it must be taken regularly as ordered by your doctor.
To help prevent kidney stones while taking allopurinol, adults should drink at least 10 to 12 full glasses (8 ounces each) of fluids each day unless otherwise directed by their doctor. Check with the doctor about the amount of fluids that children should drink each day while receiving this medicine. Also, your doctor may want you to take another medicine to make your urine less acidic. It is important that you follow your doctor's instructions very carefully.
For patients taking allopurinol for chronic gout:
- After you begin to take allopurinol, gout attacks may continue to occur for a while. However, if you take this medicine regularly as directed by your doctor, the attacks will gradually become less frequent and less painful. After you have been taking allopurinol regularly for several months, the attacks may stop completely.
- Allopurinol is used to help prevent gout attacks. It will not relieve an attack that has already started. Even if you take another medicine for gout attacks, continue to take this medicine also.
Dosing
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 the oral dosage form (tablets):
- For gout:
- Adults—At first, most people will take 100 mg a day. After about a week, your doctor will probably increase the dose gradually until the amount of uric acid in your blood has been lowered to normal levels. The total amount of allopurinol is usually not more than 800 mg a day. After the uric acid has remained at normal levels for a while, your doctor may lower your dose gradually until you are taking the smallest amount of medicine that will keep the uric acid from increasing again.
- Children and teenagers—Use and dose must be determined by the doctor.
- For kidney stones:
- Adults—100 to 800 mg a day, depending on the kind of kidney stones.
- Children and teenagers—Use and dose must be determined by the doctor.
- For preventing or treating medical problems that may occur if certain treatments increase the amount of uric acid in the blood:
- Adults—600 to 800 mg a day, starting one to three days before the treatment.
- Children—The dose depends on the child's age
- Children up to 6 years of age: 50 mg (one-half of a 100-mg tablet) three times a day.
- Children 6 to 10 years of age: One 100-mg tablet three times a day or one 300-mg tablet a day.
- Children 11 years of age and older: The dose may be the same as for adults.
- For gout:
- For the parenteral dosage form (injection):
- For preventing or treating medical problems that may occur if certain treatments increase the amount of uric acid in the blood:
- Adults—200 to 400 mg per square meter of body surface area (mg/m2) a day, injected into a vein. Starting one to two days before treatment, this dose may be given as a single dose or divided into smaller doses as determined by your doctor. Your doctor will check your uric acid level and may change your dose based on the level. However, the dose is usually not more than 600 mg per day.
- Children—At first, 200 mg per square meter of body surface area (mg/m2) per day, injected into a vein. Starting one to two days before treatment, this dose may be given as a single dose or divided into smaller doses as determined by your doctor. Your doctor will check your uric acid level and may change your dose based on the level.
- For preventing or treating medical problems that may occur if certain treatments increase the amount of uric acid in the blood:
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.
Storage
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.

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