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How does allopurinol work in tumor lysis syndrome?
Allopurinol inhibits xanthine oxidase, the enzyme that synthesizes uric acid from hypoxanthine and xanthine, thus decreasing production and excretion of uric acid and increasing the levels of more soluble xanthine and hypoxanthine.
Why is uric acid high in tumor lysis syndrome?
When cancer cells break down quickly in the body, levels of uric acid, potassium, and phosphorus rise faster than the kidneys can remove them. This causes TLS. Excess phosphorus can “sop up” calcium, leading to low levels of calcium in the blood.
What is the pathophysiology of Tumour lysis syndrome?
The pathophysiology involves massive tumor cell lysis resulting in the release of large amounts of potassium, phosphate, and uric acid. Deposition of uric acid and calcium phosphate crystals in the renal tubules may lead to acute renal failure, which is often exacerbated by concomitant intravascular volume depletion.
Why is allopurinol given before chemotherapy?
Allopurinol can be given at the start of a course of chemotherapy. When chemotherapy medicines start to kill the cancer cells, uric acid is released from these cells which can crystallise causing damage to the kidneys. Allopurinol stops these crystals from forming.
Which drugs cause TLS?
Which agents may cause tumor lysis syndrome (TLS)?
- Zoledronic acid.
How does allopurinol prevent TLS?
Allopurinol and rasburicase are known to reduce uric acid levels. Allopurinol has no effect on existing hyperuricemia; thus, it can be preferentially used in patients with low or intermediate risk for TLS. Rasburicase, on the other hand, rapidly reduces existing hyperuricemia.
What is the treatment for tumor lysis syndrome?
In general, treatment of TLS consists of intensive hydration, stimulation of diuresis, and, more specifically, in the use of allopurinol and rasburicase.
When should allopurinol be used for tumor lysis syndrome?
Treatment with allopurinol should be started at least 24 hours before initiation of anticancer therapy and should be continued until normalization of uric acid levels and signs of large tumor burden are absent.
Why is allopurinol prescribed to leukemia?
Allopurinol is FDA approved for management of patients with leukemia, lymphoma, and cancers who are receiving cancer therapy that causes elevations of uric acid levels in association with tumor lysis syndrome. What is the mechanism of action? Allopurinol works by reducing the formation of uric acid.
When should allopurinol be used?
Allopurinol is used to prevent or lower high uric acid levels in the blood. It is also used to prevent or lower excess uric acid levels caused by cancer medicines or in patients with kidney stones. A high uric acid level can cause gout or gouty arthritis (joint pain and inflammation).
How does allopurinol work mechanism of action?
Allopurinol works by reducing the amount of uric acid made by body cells. In gout, this helps prevent uric acid crystals building up in the joints. This helps prevent joints becoming swollen and painful. In cancer, some cancer treatments kill cancer cells and uric acid is then released from these cells.
How does allopurinol work biochemistry?
Allopurinol is in a class of medications called xanthine oxidase inhibitors. It works by reducing the production of uric acid in the body. High levels of uric acid may cause gout attacks or kidney stones. Allopurinol is used to prevent gout attacks, not to treat them once they occur.
What is the action of allopurinol?
Why does leukemia cause hyperuricemia?
Although hyperuricemia is seldom report- ed, it is not an uncommon complication of therapy in leukemia and lymphoma. Severe hyperuricemia results from the rapid break- down of leukemic and lymphomatous cells, especially during effective chemotherapy or irradiation.
How does allopurinol inhibit xanthine oxidase?
Allopurinol. Allopurinol, a xanthine oxidase inhibitor, acts as a neuroprotectant by preventing formation of free radicals that trigger programmed cell death. Free radical production occurs after reperfusion and reoxygenation after an hypoxic-ischemic insult.
What is the indication of allopurinol?
Allopurinol is FDA approved for the following indications: Gout. Prevention of tumor lysis syndrome. Prevention of recurrent calcium nephrolithiasis in patients with hyperuricosuria.