Allopurinol (4 brand names, 1 dosage form, 1 route)
Available dosage forms: TABLET.
Routes of administration: ORAL.
Brand Names
- ALLOPURINOL
- DUZALLO
- LOPURIN
- ZYLOPRIM
Indications and Usage
Allopurinol tablets are indicated for: •The management of adults with signs and symptoms of primary or secondary gout (acute attacks, tophi, joint destruction, uric acid lithiasis, and/or nephropathy) •The management of adult and pediatric patients with leukemia, lymphoma and solid tumor malignancies who are receiving cancer therapy which causes elevations of serum and urinary uric acid levels •The management of adult patients with recurrent calcium oxalate calculi whose daily uric acid excretion exceeds 800 mg/day in male patients and 750 mg/day in female patients, despite lifestyle changes (such as reduction of dietary sodium, non-dairy animal protein, oxylate rich foods, refined sugars and increases in oral fluids and fruits and vegetables) Limitations of Use Allopurinol tablets are not recommended for the treatment of asymptomatic hyperuricemia.
Contraindications
Allopurinol tablets are contraindicated in patients with a history of hypersensitivity reaction to allopurinol or to any of the ingredients of allopurinol tablets.
Adverse Reactions
The following clinically significant adverse reactions are described elsewhere in the labeling: •Skin Rash and Hypersensitivity [see Warnings and Precautions (5.1)] •Nephrotoxicity [see Warnings and Precautions (5.3)] •Hepatoxicity [see Warnings and Precautions (5.4)] •Myelosuppression [see Warnings and Precautions (5.5)] •Potential Effect on Driving and Use of Machinery [see Warnings and Precautions (5.6)] The following adverse reactions associated with the use of allopurinol tablets were identified in literature, unpublished clinical trials or postmarketing reports. Because some of these reactions were reported voluntarily from a population of uncertain size, it is not always possible to reliably estimate their frequency or establish a causal relationship to drug exposure. The most frequent adverse reaction to allopurinol tablets is skin rash. Most Common Adverse Reactions (≥ 1%) Gastrointestinal: Diarrhea, nausea, alkaline phosphatase increase, AST/ALT increase. Metabolic and Nutritional: Acute attacks of gout. Skin and Appendages: Rash, maculopapular rash. Less Common Adverse Reactions (< 1%) Body As a Whole: Ecchymosis, fever, headache, malaise. Cardiovascular: Necrotizing angiitis, vasculitis, pericarditis, peripheral vascular disease, thrombophlebitis, bradycardia, vasodilation. Gastrointestinal: Hepatic necrosis, granulomatous hepatitis, hepatomegaly, hyperbilirubinemia, cholestatic jaundice, vomiting, intermittent abdominal pain, gastritis, dyspepsia, hemorrhagic pancreatitis, gastrointestinal bleeding, stomatitis, salivary gland swelling, hyperlipidemia, tongue edema, anorexia. Hemic and Lymphatic: Thrombocytopenia, eosinophilia, leukocytosis, leukopenia, aplastic anemia, agranulocytosis, eosinophilic fibrohistiocytic lesion of bone marrow, pancytopenia, prothrombin decrease, anemia, hemolytic anemia, reticulocytosis, lymphadenopathy, lymphocytosis. Musculoskeletal: Myopathy, arthralgias, myalgia. Nervous: Peripheral neuropathy, neuritis, paresthesia, somn
Mechanism of Action
Allopurinol tablets are a structural analogue of the natural purine base, hypoxanthine. Allopurinol acts on purine catabolism, without disrupting the biosynthesis of purines. It reduces the production of uric acid by inhibiting the biochemical reactions immediately preceding its formation. It is an inhibitor of xanthine oxidase, the enzyme responsible for the conversion of hypoxanthine to xanthine and of xanthine to uric acid, the end product of purine metabolism in humans. Allopurinol is metabolized to the corresponding xanthine analogue, oxypurinol (alloxanthine), which also is an inhibitor of xanthine oxidase.
Overdosage
In the management of overdosage there is no specific antidote for allopurinol tablets. Both allopurinol tablets and oxipurinol are dialyzable; however, the usefulness of hemodialysis or peritoneal dialysis in the management of an overdose of allopurinol tablets is unknown.