Tumor lysis syndrome (TLS) is caused by the release of intracellular products into the blood following rapid lysis of malignant cells resulting in hyperuricemia, hyperkalemia, hyperphosphatemia, and hypocalcemia. Complications of TLS include acute renal failure, cardiac arrhythmias, seizure, and sudden death. Allopurinol is commonly initiated as prophylaxis for patients at risk for TLS to prevent buildup of uric acid and decrease the incidence of obstructive uropathy caused by uric acid precipitation. Allopurinol takes several days to reduce uric acid levels, therefore it is recommended to initiate allopurinol 1 to 2 days prior to the start of chemotherapy and continue until the risk of TLS has ceased, usually within 7 days of chemotherapy initiation. Unnecessarily continuing allopurinol beyond 10 days increases the risk of adverse events, including allergic skin rashes and myelosuppression. A report of allopurinol orders for TLS from March 1, 2020, to March 31, 2021 was generated. Of these orders, there were 44 unique patients and 56 total allopurinol courses. The median duration of allopurinol for TLS was 39 days, with a duration of allopurinol of 10 days or less in 10 (18.2%) cases.
On September 16, 2021, inpatient prescribing of new allopurinol orders was restricted to an inpatient order menu with quick orders designating an indication of gout or TLS in the comment section. The TLS quick order was defaulted to a dose of 300 mg for 10 days. Education was also provided to the medical staff. Descriptive statistics were used.
Since implementation of the allopurinol order menu, 17 patients with cancer have initiated allopurinol for TLS. The menu was used in 14 (82.4%) patients. The median duration of allopurinol was 8 days and 11 (64.7%) allopurinol courses were 10 days or less. The main reasons for not using the allopurinol menu were due to dose reduction of allopurinol due to renal dysfunction or the primary hematologist/oncologist ordering outpatient allopurinol prior to admission for chemotherapy.
The introduction of an inpatient allopurinol order menu has decreased excessive allopurinol therapy when utilized for TLS. This has resulted in decreased pill burden, adverse events, and cost.