FOR THE CONSUMER
Along with its needed effects, allopurinol 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 while taking allopurinol:
-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
-blistering, peeling, or loosening of the skin
-blood in the urine or stools
-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
-cough or hoarseness
-coughing up blood
-cracks in the skin
-decreased urine output
-difficulty with breathing
-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
-joint or muscle pain
-large, flat, blue or purplish patches in the skin
-loss of appetite
-loss of heat from the body
-lower back or side pain
-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
-severe stomach pain
-shortness of breath
-slow or irregular heartbeat
-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 of allopurinol 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:
-Bad, unusual, or unpleasant (after) taste
-blue-yellow color blindness
-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
-difficulty with moving
-discharge or excessive tearing
-feeling of constant movement of self or surroundings
-hair loss or thinning of the hair
-hives or welts
-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
-problems with memory
-redness, pain, or swelling of the eye, eyelid, or inner lining of the eyelid
-sensation of spinning
-sensitivity to light
-sleepiness or unusual drowsiness
-swelling of the breasts or breast soreness in both females and males
-swelling of the salivary glands
-swelling or inflammation of the mouth
-tender, swollen glands in the neck
-tenderness in the stomach area
-tightness in the chest
-trouble getting pregnant
-trouble with sleeping
-trouble with swallowing
-unable to sleep
-unsteadiness or awkwardness
-weakness in the arms, hands, legs, or feet
USUAL ADULT DOSE FOR GOUT
Initial: 100 mg orally once a day.
Maintenance: 200 to 300 mg (mild gout) orally once a day or 400 to 600 mg/day (moderately severe tophaceous gout) in divided doses.
USUAL ADULT DOSE FOR HYPERURICEMIA SECONDARY TO CHEMOTHERAPY
Parenteral: 200 to 400 mg/m2/day to a maximum of 600 mg/day
Oral: 600 to 800 mg/day for 1 to 3 days with consumption of at least 2 L of fluid/day.
200 to 300 mg/day orally until patient no longer at high risk for developing hyperuricemia.
USUAL ADULT DOSE FOR CALCIUM OXALATE CALCULI WITH HYPERURICOSURIA
Initial: 200 to 300 mg orally once a day.
Maintenance: 300 mg/day or less.
USUAL ADULT DOSE FOR CONGESTIVE HEART FAILURE
Study (n=11) to prevent the formation of superoxide free radicals and improve endothelial function (in NYHA class II to III chronic heart failure): 300 mg orally daily for 1 month
USUAL AUDLT DOSE FOR CARDIOTHORACIC SURGERY
Studies: Coronary Artery Bypass Graft Surgery
600 mg orally one day prior to surgery and another 600 mg orally the day of surgery.
USUAL ADULT DOSE FOR LEISHMANIASIS
Study (n=31 - Cutaneous leishmaniasis: 20 mg/kg/day plus low-dose meglumine antimoniate (30 mg/kg/day) for 20 days.
Case Reports - Visceral leishmaniasis, post renal transplant: 300 mg daily plus meglumine antimoniate (50 mg/kg/day)
USUAL ADULT DOSE FOR MANIA
Case Reports -- Mania (bipolar I) associated with hyperuricemia: 300 mg orally daily.
USUAL ADULT DOSE FOR HIGH RISK PERCUTANEOUS TRANSLUMINAL ANGIOPLASTY
Study (n=38) - Primary Percutaneous Transluminal Coronary Angioplasty (PTCA):
400 mg orally administered immediately after admission to the emergency department (approximately 60 minutes before reperfusion) and after primary PTCA was completed.
USUAL ADULT DOSE FOR REACTIVE PERFORATING COLLANGENOSIS
Case Report: 100 mg orally daily.
USUAL PEDIATRIC DOSE FOR HYPERURICEMIA SECONDARY TO CHEMOTHERAPY
Less than or equal to 10 years: 200 mg/m2/day in 1 to 3 equally divided doses not to exceed 600 mg/24 hours. All doses greater than 300 mg should be given in equally divided doses.
Greater than 10 years: 200 to 400 mg/m2/day administered in 1 to 3 equally divided doses, not to exceed 600 mg/24 hours.
Less than 6 years: 150 mg/day orally in 3 divided doses.
6 to 10 years: 300 mg/day orally in 2 to 3 divided doses.
Greater than 10 years: 600 to 800 mg/day in 2 to 3 equally divided doses
USUAL PEDIATRIC DOSE FOR LEISHMANIASIS
Greater than 5 years old
Study (n=31) - Cutaneous leishmaniasis: 20 mg/kg/day plus low-dose meglumine antimoniate (30 mg/kg/day) for 20 days.
RENAL DOSE ADJUSTMENTS
CrCl less than 3 mL/min: 100 mg/day at extended intervals
CrCl 3 to 10 mL/min: 100 mg/day
CrCl 10 to 20 mL/min: 200 mg/day
CrCl less than 10 mL/min: 100 mg orally three times per week.
CrCl 10 mL/min: 100 mg orally on alternate days.
CrCl 20 mL/min: 100 mg orally once a day.
CrCl 40 mL/min: 150 mg orally once a day.
CrCl 60 mL/min: 200 mg orally once a day.
For treating gout, the dose should be titrated at weekly intervals to achieve the desired clinical response, typically a serum uric acid level of 6 mg/dl or less. Normal serum urate levels are usually achieved in 1 to 3 weeks. Doses greater than 300 mg/day should be given in divided doses.
Allopurinol for injection in combination therapy with mercaptopurine or azathioprine will require dose reductions of one-third to one-fourth the usual dose of mercaptopurine or azathioprine.
In transferring a patient from a uricosuric agent to allopurinol, the dose of the uricosuric agent should be gradually reduced over a period of several weeks and the dose of allopurinol gradually increased to the required dose needed to maintain a normal serum uric acid level.
Allopurinol should be discontinued at the first sign of skin rash or any other signs or symptoms suggestive of a hypersensitivity reaction. In some instances, a skin rash may be followed by more severe adverse reactions such as exfoliative, urticarial, and purpuric lesions, as well as Stevens-Johnson syndrome (erythema multiforme exudativum), and/or generalized vasculitis, irreversible hepatotoxicity, and, rarely, death. Renal dysfunction increases the risk of allopurinol hypersensitivity.
A few cases of reversible clinical hepatotoxicity have been observed in patients administered allopurinol, and in some patients, asymptomatic rises in serum alkaline phosphatase or serum transaminase have been reported. Monitor liver function closely in patient who develop anorexia, weight loss, or pruritus, and in patients with pre-existing liver disease. Liver function tests are recommended at initiation of therapy.
Because allopurinol has been associated with drowsiness, patients should be cautious when engaging in activities where alertness is mandatory.
An increase in acute attacks of gout have been observed during the early stages of use of allopurinol, even when normal or subnormal serum uric acid levels have been reached. Accordingly, maintenance doses of colchicine generally should be given prophylactically when allopurinol therapy is started. The administration of colchicine or anti-inflammatory agents may be necessary to suppress gouty attacks in some instances. The gout attacks usually become shorter and less severe after several months of treatment. The mobilization of urates from tissue deposits which lead to fluctuations in the serum uric acid levels may be a possible explanation for these attacks. Even with adequate allopurinol treatment, it may require several months to deplete the uric acid pool adequately to achieve control of the acute attacks.
In the case of allopurinol injection, hydration to yield a daily urinary output of at least 2 L in adults and the maintenance of a slightly alkaline urine are recommended by the manufacturer to avoid the formation of xanthine calculi, and to prevent renal precipitation of urates in patients also receiving uricosuric drugs.
Some patients with preexisting renal disease or poor urate clearance have shown a rise in BUN during allopurinol therapy. Although the mechanism responsible for this has not been determined, patients with impaired renal function should be carefully monitored during the early stages of allopurinol use and the dosage decreased or the drug withdrawn if increased abnormalities in renal function appear and persist. Renal failure in association with allopurinol use has been reported among patients with hyperuricemia secondary to neoplastic diseases. Concurrent conditions such as multiple myeloma and congestive myocardial disease were present among those patients whose renal dysfunction increased after allopurinol therapy was started. Renal failure is frequently observed with the use of allopurinol therapy. Albuminemia has been observed in patients who developed clinical gout following chronic glomerulonephritis and chronic pyelonephritis. Patients with decreased renal function require lower doses of allopurinol therapy than those with normal renal function. Periodic monitoring of renal function is recommended during the course of therapy.
Bone marrow depression has been observed in patients receiving allopurinol therapy, most of whom received concomitant drugs with the potential for causing this adverse event. This has occurred as early as 6 weeks to as long as 6 years after the start of allopurinol. Rarely, a patient may develop varying degrees of bone marrow depression, affecting one or more cell lines, while receiving allopurinol therapy alone.
Prothrombin time should be reassessed periodically in patients receiving dicumarol and allopurinol.
Allopurinol is dialyzable. The dose may be given post hemodialysis or a 50% supplemental dose given.
The maximum recommended daily dose is 800 mg. Due to an initial increased risk of gouty attacks, prophylactic colchicine or an NSAID should be given concurrently for at least the first 6 months of allopurinol therapy.