A case I saw  last month led me to utilizing a drug I’d never heard of before in the ED: Rasburicase.

     The drug: a recombinant urate oxidase enzyme, which converts existing uric acid to allantoin. This is key due to the higher solubility of allantoin in urine. Patients with Tumor Lysis Syndrome are at risk of acute renal failure due to precipitation of uric acid crystals in renal tubules and collecting ducts.

The case: a 12 yo F with no PMHx who was transferred from an urgent care center for multiple tender, enlarged lymph nodes and a WBC count of 98.

As we worked her up for a new presentation of a hematologic malignancy, it became evident she fit into the parameters for TLS. Initial uric acid level – 14.5 along with hyperkalemia, elevated serum LDH, and hyperphosphatemia. When Hem/Onc came on board, once labs were back, the first recommendations were hydration and Rasburicase.

Provided below is the article I found that informed me on the treatment and a few key points picked up when using it.

For kids only – The drug hasn’t been approved in the US for adults.

G6PD deficiency – Yes, from the depths of med school knowledge, this condition is a contraindication to using Rasburicase. The hydrogen peroxide it produces as a byproduct can lead to hemolysis. Ask if there is a family history.

Coordinating with pharmacy – Due to the preparation of rasburicase, it should be administered immediately after it has been prepared. IV access should be obtained well in advance.

Type of IV access – In our case, hem/onc was considering emergent dialysis. It may be prudent to discuss this with your consultants to get a head-start on what they’ll need once going upstairs.

Not at your medical facility, a specialized pediatric hospital, or somewhere with this in stock??? As you transfer, consider:

1.) Aggressive IV Hydration. Easy to start getting this started, especially if transporting to the next hospital will require hours instead of blocks.

2.) Allopurinol. Though it isn’t required when Rasburicase is given, allopurinol can’t decrease what is already present, but it can help prevent the formation of more uric acid.

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1200736/