Allopurinol can usually take effect gradually in about 2 to 6 hours, but due to differences in dosage, condition and physical fitness of individuals and other factors, the onset of its blood uric acid lowering time also varies greatly, it is recommended that the actual situation prevails. Allopurinol is a kind of drug that reduces uric acid by inhibiting uric acid production, the blood concentration of this drug can reach the peak in about 2~6 hours after entering the human body, and the effect can be gradually taken effect in this period, but the half-life of this product is 14~28 hours, so it is necessary to continue to give the drug in order to achieve the stable effect of treatment. After taking allopurinol, patients should be tested for uric acid and blood uric acid levels every 2 weeks and the dosage should be adjusted according to the results of the test. Due to the differences in the dosage of the drug, the condition of the patient and the individual’s physical condition, the onset of action of allopurinol is also different. Allopurinol is mainly used for the treatment of primary and secondary hyperuricemia, especially hyperuricemia caused by excessive production of uric acid; recurrent or chronic gout; gout stones; uric acid kidney stones and (or) uric acid nephropathy; hyperuricemia with renal insufficiency. Allopurinol may cause adverse reactions such as abnormalities in liver and kidney function. It is generally contraindicated in people who are allergic to the product, have severe hepatic or renal insufficiency and markedly low blood counts. Note that this product cannot control the acute inflammatory symptoms of gouty arthritis, and cannot be used as an anti-inflammatory drug. It should not be used as an anti-inflammatory drug, because it may trigger and aggravate the acute phase of arthritis when it induces the re-dissolution of uric acid crystals. Allopurinol should be used under the supervision of a physician, do not use the drug without authorization, in order to avoid adverse effects.