pegvisomant at a glance
Medicine class
Growth hormone receptor antagonist
Main use
Adult acromegaly not adequately controlled by established treatments
Key monitoring
IGF-I, liver function and pituitary tumour status
What is pegvisomant used for?
UK-licensed use:
Treatment of adults with acromegaly whose response to surgery and/or radiotherapy was inadequate and whose IGF-I was not normalised by an appropriate somatostatin analogue, or who could not tolerate that treatment.
How does pegvisomant work?
Pegvisomant is a modified analogue of human growth hormone. It occupies growth hormone receptors without activating them, blocking growth hormone signalling and reducing production of IGF-I, an important mediator of acromegaly.
pegvisomant preparations and strengths
Injection
Route: Parenteral
Strengths: 10 mg, 15 mg, 20 mg, 25 mg, 30 mg
How to take pegvisomant
Pegvisomant is injected into the fatty layer beneath the skin. Use it only after training and follow the supplied preparation instructions.
Mix the powder only with the supplied solvent when ready to inject.
Add the solvent slowly and swirl gently; do not shake or create foam.
Use a different injection location each time and avoid bruised, sore, hard or scarred skin.
Use the solution immediately after mixing. Do not inject it if cloudy, coloured, foamy or particle-containing.
Never reuse the syringe or needle; place them in an appropriate sharps container.
pegvisomant side effects
Common or expected effects
- Headache
- Joint pain
- Diarrhoea
- Nausea, vomiting, constipation or abdominal discomfort
- Injection-site soreness, bruising, bleeding, swelling or fatty thickening
- Dizziness, sleepiness or tremor
- Muscle pain, tiredness or flu-like symptoms
- Changes in liver-function or blood-glucose test results
Get urgent medical advice
- Severe allergic reaction, including angioedema, anaphylaxis or laryngeal spasm
- Symptoms of liver injury, such as jaundice, dark urine, persistent nausea or right-sided upper abdominal pain
- Hypoglycaemia, particularly in people using insulin or other glucose-lowering treatment
- New headache or visual disturbance that could indicate pituitary tumour enlargement
pegvisomant in pregnancy
Human pregnancy information is limited, and the UK product information does not recommend pegvisomant during pregnancy or for people who could become pregnant without contraception. Anyone pregnant or planning pregnancy should discuss treatment promptly with their endocrinology team; if treatment is continued, specialist IGF-I monitoring is required.
pegvisomant while breastfeeding
It is uncertain whether pegvisomant enters human milk because clinical evidence is extremely limited. UK product information advises against its use while breastfeeding; the balance between maternal treatment and breastfeeding should be reviewed with the specialist team.
pegvisomant interactions
Formal interaction studies are limited. Important practical considerations include:
Insulin and other glucose-lowering medicines
Pegvisomant can improve insulin sensitivity, increasing the risk of low blood glucose; glucose monitoring and treatment review may be needed.
Somatostatin analogues and other acromegaly treatments
Combination use has not been extensively investigated, so the specialist should decide whether existing treatment continues.
Common questions about pegvisomant
Answers are fully visible for fast scanning and source review.
What is pegvisomant used for?
Pegvisomant treats adult acromegaly when surgery or radiotherapy has not provided adequate control and suitable somatostatin analogue treatment has failed or was not tolerated.
Is pegvisomant a form of growth hormone?
It is a modified growth hormone analogue, but it acts as an antagonist: it blocks rather than activates growth hormone receptors.
Does pegvisomant shrink a pituitary tumour?
Its main action is to block growth hormone effects outside the pituitary; it is not relied upon to shrink the tumour. Continued tumour monitoring is therefore important.
Sources
These sources were used to prepare and review this medicine page.
Prepared and reviewed by the iatroX editorial team.