Asparaginase (L-asparaginase)

What is this medication for?

• Lymphoid malignancies — induction (and rescue/maintenance) of lymphoma; acute lymphoblastic leukemia; usually in combination (CHOP-based) — inclusion in first-line protocols now debated (MacDonald 2005: no outcome difference ± drug)

How is it given?

Give exactly as your veterinarian prescribed — never change the dose or stop on your own unless your veterinarian has told you to.

• A lymphoma patient with sudden abdominal pain + bleeding on therapy → think asparaginase pancreatitis + hypofibrinogenemia, not marrow suppression.

What if I miss a dose?

• Give it as soon as you remember — unless it is almost time for the next dose (then skip the missed one; never double up).
• Call your clinic if you miss more than one dose in a row.

Side effects — what should I watch for?

Effects listed as common in this handout

• Hyperglycemia (with prednisone) (Combined-protocol effect)

Worth a phone call to your veterinarian

• Protein-synthesis toxicities: hemorrhagic pancreatitis, liver damage, coagulation disorders (↓ATIII, ↓fibrinogen), stomach/intestinal effects (The second axis)
• Marrow suppression (RARE (its distinguishing feature))

⚠️ Contact your veterinarian or an emergency clinic IMMEDIATELY if you notice

• Hypersensitivity/anaphylaxis (foreign E. coli protein) (Main acute risk — worse into a vein; premedicate)

Before starting (or refilling), tell your veterinarian if your pet:

• has or has had: Prior anaphylaxis to it; pancreatitis history; bleeding disorders; hepatic impairment

• is pregnant, nursing, or used for breeding
• is taking any other medications, supplements, or flea/tick products, including:
  • Prednisone
  • Methotrexate
  • Vincristine
  • Thyroid tests

Storage and handling

Lyophilized powder; reconstitute gently (do NOT shake — inactivates); use promptly; keep chilled. Chemo handling.

Good to know

• The marrow-sparing chemotherapeutic: toxicity profile = anaphylaxis + protein-starvation organs (pancreas, liver, clotting), NOT low infection-fighting cell counts.
• into a muscle/under the skin only in practice — the into a vein route amplifies anaphylaxis; premedicate with diphenhydramine.
• Unique selectivity logic: lymphoblasts can't make their own asparagine; normal cells can — the exam-friendly "metabolic hostage-taking" drug.
• A lymphoma patient with sudden abdominal pain + bleeding on therapy → think asparaginase pancreatitis + hypofibrinogenemia, not marrow suppression.