Mercaptopurine and azathioprine
Patients using mercaptopurine and azathioprine are at an increased risk when using Allopurinol. These patients may experience harmful effects. While using 300-600 mg Allopurinol, the dose adjustment of mercaptopurine and azathioprine is required and a low dose of these drugs should be used.
Patients with existing liver disease are at an increased risk when using this medicine. These patients may have reversible liver damage and level of some liver enzymes may also increase. They may develop symptoms like weight loss, itching
, and an eating disorder (anorexia). In such cases, regular monitoring of liver function is recommended. The dose of Allopurinol should be reduced in such patients.
Patients receiving Allopurinol are at increased risk of allergic reactions. Such patients are at an increased risk of allergic reactions such as skin rash, shedding old skin, hives
, red or purple discolored spots on the skin, severe skin reaction (Stevens-Johnson syndrome
), drug-induced reactions (DRESS), inflammation of blood vessels, irreversible liver damage, and can be fatal. Allopurinol should be discontinued if these allergic reactions occur. Corticosteroids
treatment may be given to such patients.
Decreased functioning of the kidney
Patients with kidney dysfunction taking treatment for heart failure or high blood pressure such as ACE inhibitors or diuretics
are at an increased risk while taking Allopurinol. The incidence of allergic reactions is increased in such patients. The close monitoring and caution are advised in these patients. The dose of Allopurinol should be reduced in such patients.
Patients with gout
attack are at an increased risk while taking Allopurinol. The occurrence of a gout attack may be increased while taking drugs that increase the excretion of uric acid in the urine with Allopurinol. Colchicine or anti-inflammatory agent are advised to use for one month as preventive
therapy in such patients. If gout attack occurs during Allopurinol therapy, the treatment with this medicine should be continued with usual dose while gout attack is treated with an anti-inflammatory agent.
Patients with cancer
and Lesch-Nyhan syndrome
are at an increased risk while taking Allopurinol. Patients with an increased formation of urate are at an increased risk of xanthine deposition in the urinary tract. Take adequate fluids to increase the production of urine to minimize the risk of xanthine deposition.
Uric acid kidney stones
The therapy with Allopurinol can dissolve uric acid kidney stones and may lead to an impact on the ureter.
Patients on long-term therapy of Allopurinol are at an increased risk. There is a risk of an increase in thyroid stimulating hormone
(TSH) in such patients. The patients should be cautious while taking Allopurinol.
Patients with birth defects of lactose intolerance, abnormal absorption of glucose-galactose or the Lapp lactase deficiency are at an increased risk while taking Allopurinol. Allopurinol should not be given to such patients because it contains lactose.
Patients having HLA-B*5801 gene
Patients having HLA-B*5801 gene are at an increased risk while taking Allopurinol. This gene is mainly present in Han Chinese, Thai, Korean, Japanese or European origin population. There is a risk of developing allergic reactions in such patients. The presence of HLA-B*5801 gene should be tested before starting treatment with Allopurinol in such patients. Allopurinol should not be given to these patients unless there is no other treatment available or taking the benefits outweigh the risk in consideration. The close monitoring of symptoms of the allergic reactions advised in such patients.