. WHAT IS THIS MEDICINE AND WHAT IS IT USED
FOR?
PEG L-Aspatero contains pegaspargase — a form of the enzyme
L-asparaginase that has been chemically modified (attached to polyethylene
glycol, or PEG) to last longer in the body and reduce the risk of allergic
reactions compared to older asparaginase preparations.
It is used as part of combination chemotherapy regimens for the treatment
of acute lymphoblastic leukaemia (ALL) — a fast-growing cancer of the white
blood cells (lymphocytes) that is one of the most common cancers in children,
though it also affects adults.
Cancer cells in ALL cannot make their own supply of a particular amino
acid called asparagine — they rely on the body's own supply from the blood.
Pegaspargase breaks down asparagine in the blood, effectively starving ALL
cancer cells of this essential building block. Normal cells are largely
unaffected because they can make their own asparagine. Pegaspargase is always
used as part of a multi-drug protocol prescribed and supervised by a specialist
haematology or paediatric oncology team.
3. HOW TO TAKE THIS MEDICINE
Pegaspargase is given by injection — either into a muscle (intramuscular
injection) or into a vein (intravenous infusion) — by trained healthcare staff
in a hospital or clinic. It is never self-administered.
The dose is calculated based on body surface area (a calculation using
height and weight). A typical dose is 2,500 IU per square metre of body surface
area, given every 14 days as part of the prescribed ALL treatment protocol. The
exact schedule will be determined by the treating haematologist or paediatric
oncologist.
Pegaspargase must only be given in a clinical setting with facilities for
managing allergic reactions, including anaphylaxis. Patients should be observed
for at least 1 hour after each dose. Pre-medication (antihistamine,
paracetamol) may be given before the infusion to reduce the risk of
hypersensitivity reactions.
⚠ PATIENT TIP: Tell the nursing team immediately
during or after your injection if you notice any flushing, difficulty
breathing, throat tightening, rash, or sudden drop in blood pressure. These can
be signs of a serious allergic reaction and need immediate treatment.
4. POSSIBLE SIDE EFFECTS
|
How Common? |
Side Effects |
|
Common |
Nausea, vomiting,
fatigue, loss of appetite, raised liver enzyme levels on blood tests,
elevated blood sugar (hyperglycaemia), raised triglyceride levels |
|
Less Common |
Allergic reactions
(rash, hives, flushing, low blood pressure), reduced blood clotting function
(which can cause either increased bleeding or blood clots), reduced
production of certain liver proteins |
|
Serious — Seek
Emergency Help |
Anaphylaxis (severe
allergic reaction): breathlessness, throat swelling, collapse — emergency
treatment needed immediately. Pancreatitis (inflammation of the pancreas):
severe, persistent central or upper tummy pain, often radiating to the back,
with nausea and vomiting — stop the medicine and seek urgent medical care.
Serious blood clotting problems: both dangerous blood clots (thrombosis) and
abnormal bleeding can occur. Severe liver toxicity. Hyperglycaemia severe
enough to require insulin treatment. |
5. WHO SHOULD NOT TAKE THIS MEDICINE
Pegaspargase must not be given to patients who have had a previous
serious allergic reaction (anaphylaxis) to pegaspargase or to other
asparaginase preparations, or who have had serious pancreatitis with a prior
asparaginase treatment. It must not be used in patients with active, serious
blood clotting disorders. Use with great caution in patients with liver
disease. Always performed under specialist supervision only.
⚠ PANCREATITIS RISK: Pancreatitis (inflammation
of the pancreas) is one of the most serious risks of asparaginase therapy.
Patients and carers must know to report persistent severe tummy pain
immediately — particularly pain in the middle or upper abdomen that radiates to
the back, accompanied by nausea. Serum amylase and lipase are monitored before
and during treatment.
⚠ CLOTTING ABNORMALITIES: Pegaspargase reduces
the liver's production of clotting proteins, which can increase both bleeding
and clotting (thrombosis) risk. Coagulation tests (PT, aPTT, fibrinogen) are
monitored during treatment. Report unusual bruising, prolonged bleeding, or any
sudden pain, swelling, or redness in a limb.
⚠ BLOOD SUGAR: Pegaspargase can cause
significant rises in blood sugar. Blood glucose monitoring is important during
treatment — particularly in patients with diabetes or those receiving
concurrent corticosteroids.
6. MEDICINES THAT INTERACT WITH THIS TREATMENT
Pegaspargase reduces the liver's production of coagulation factors, which
can affect the activity of anticoagulants (warfarin, heparin) and antiplatelet
medicines — close monitoring is needed.
Methotrexate and cytarabine (other chemotherapy agents commonly used in
ALL protocols) have complex sequence-dependent interactions with asparaginase —
timing within the protocol is carefully planned by the oncology team.
Concurrent corticosteroids (such as prednisolone or dexamethasone,
routinely used in ALL treatment) increase the risk of hyperglycaemia and
thrombosis when combined with pegaspargase.
7. HOW TO STORE THIS MEDICINE
Store in a refrigerator at 2–8°C. Do not freeze — freezing destroys the
enzyme. Protect from light. Do not shake. Use immediately after preparation.
Single-use vial — discard any unused portion.
8. PRESCRIPTION REQUIREMENT
|
Field |
Details |
|
Status |
Prescription Only
Medicine (POM) — Specialist (haematology or paediatric oncology) prescription
required; hospital administration only |
9. GUIDANCE FOR PATIENTS & CAREGIVERS
This medicine will be given to you or your child in hospital by a nurse
or doctor. You will be observed for at least 1 hour after each dose. Report any
unusual symptoms immediately — particularly tummy pain, difficulty breathing,
rash, or any swelling.
Between clinic visits, report persistent severe tummy pain to your care
team straight away without waiting for the next appointment — this could
indicate pancreatitis, which is a medical emergency. Report any unusual
bruising, prolonged bleeding, or a swollen, red, or painful limb promptly. Keep
all monitoring blood test appointments.
10. PHARMACIST & PRESCRIBER NOTES
|
Field |
Details |
|
Clinical Dispensing
Notes |
Pegaspargase is a
specialist oncology enzyme preparation used exclusively in ALL treatment
protocols. Hospital pharmacy preparation only — verify dose in IU/m² against
current BSA calculation. Anaphylaxis risk: must be administered in a setting
with resuscitation equipment; observe for minimum 1 hour post-injection.
Pre-medication per local protocol (antihistamine +/- paracetamol). Cold
chain: 2–8°C — do not freeze or shake. Monitor: serum amylase/lipase
(pancreatitis), blood glucose (hyperglycaemia), coagulation profile (PT,
aPTT, fibrinogen, anti-Xa if anticoagulated), LFTs, triglycerides, and
bilirubin. Coagulation protein depletion — interaction with warfarin,
heparin. Timing relative to methotrexate and cytarabine as per protocol.
Concurrent corticosteroid-associated hyperglycaemia and VTE risk heightened. |
11. FREQUENTLY ASKED QUESTIONS
Q: What is the most serious side effect to watch for?
Pancreatitis — inflammation of the pancreas — is one of the most serious
risks. It causes persistent, severe pain in the upper or middle abdomen, often
spreading to the back, along with nausea and vomiting. If you or your child
develops this kind of pain after receiving pegaspargase, seek medical help
immediately — do not wait for the next scheduled appointment.
Q: Can it cause blood clots?
Yes — pegaspargase reduces the liver's ability to produce certain
proteins that keep the blood's clotting system balanced. This can increase both
the risk of blood clots (thrombosis) and abnormal bleeding. Your care team will
monitor your clotting tests. Report any leg swelling, redness, or pain, or any
sudden breathlessness.
Q: Is the 'PEG' version safer than older asparaginase?
Pegaspargase has a longer half-life than older asparaginase preparations
(meaning fewer injections are needed) and causes fewer allergic reactions in
most patients. However, it still carries the same core risks — particularly
pancreatitis, clotting abnormalities, and allergic reactions — which is why it
is always given under close specialist supervision.
Q: What should carers watch for at home between treatments?
The main things to watch for are: persistent severe tummy pain
(pancreatitis), unusual bruising or prolonged bleeding (clotting problems), leg
swelling or redness (possible blood clot), signs of high blood sugar (increased
thirst, frequent urination, tiredness), and any signs of infection (fever,
feeling very unwell). Contact the oncology team promptly with any of these
concerns.