- Injection 10 mg
- Injection 15 mg
- Injection 20 mg
Selectively binds to growth hormone receptors on cell surfaces, where it blocks the binding of endogenous growth hormone, interfering with growth hormone transduction.
Following subcutaneous administration, C max is generally not attained until 33 to 77 h.
Mean apparent Vd is 7 L.
After multiple dosing, the mean total body clearance is estimated to range between 36 to 28 mL/h for subcutaneous doses ranging from 10 to 20 mg/day, respectively. Following either single or multiple doses, the mean elimination t ½ is approximately 6 days.
Indications and Usage
Treatment of acromegaly in patients who have had an inadequate response to surgery or radiation therapy or other medical therapies.
Dosage and AdministrationAdults
Subcutaneous 40 mg loading dose under health care provider supervision; then instruct patient to begin daily injections of 10 mg. Measure serum insulin-like growth factor-I (IGF-I) levels every 4 to 6 wk, at which time, increase the dose in 5 mg increments if IGF-I levels are still elevated or decrease the dose in 5-mg decrements if IGF-I levels have decreased below the normal range.
- For subcutaneous administration only. Not for intradermal, IM, or IV administration.
- Follow manufacturer's instructions for reconstitution of powder for injection.
- Do not shake vial during reconstitution process.
- Do not administer if particulate matter, cloudiness, or discoloration noted.
- Rotate injection sites (eg, thigh, abdomen, upper arm). Give new injections at least 1 inch from old site and never into areas where the skin is tender, bruised, red, or hard.
- Discard any unused solution. Do not save unused solution for later administration.
Store unopened vials in refrigerator (36° to 46°F). Do not freeze. Use reconstituted solution within 6 h.
Drug InteractionsInsulin, oral hypoglycemic agents
Dose may need to be reduced after starting pegvisomant.Opioids
May need higher pegvisomant serum levels to achieve appropriate IGF-I suppression.
Laboratory Test Interactions
Because of structural similarities, pegvisomant may cross-react in commercially available growth hormone assays.
Injection site reaction.
Elevated ALT and AST.
Infection; accidental injury; back pain; pain; peripheral edema; chest pain; flu-like syndrome; paresthesia.
Assess liver enzymes prior to starting therapy. Do not start therapy if liver enzymes are greater than 3 times upper limit of normal. Monitor liver enzymes monthly for 1 yr and then biannually for 1 yr if liver enzymes are elevated but are less than 3 times upper limit of normal.
Category B .
Safety and efficacy not established.
Select dose with caution, reflecting greater frequency of decreased hepatic, renal, or cardiac function, and comorbidity.
Because growth hormone opposes the effects of insulin on carbohydrate metabolism by decreasing insulin sensitivity, glucose tolerance may increase in some patients. Monitor blood sugar in diabetic patient when drug is started or dose is changed. Report significant changes to health care provider. Be prepared to reduce the dose of insulin or oral hypoglycemic agents.
Growth hormone deficiency
A state of functional growth hormone deficiency may occur.
Elevations of serum concentrations of ALT and AST greater than 10 times the upper limit of normal have been reported.
Tumors that secrete growth hormone may expand and cause serious complications.
- Advise patient or caregiver that dose will be carefully adjusted based on results of lab tests that are done periodically.
- If patient or caregiver will be administering at home, review “Patient Information” insert with the patient or caregiver. Ensure that the patient or caregiver understands how to store, prepare, and administer the dose, and dispose of used equipment and supplies. The first injection should be performed under the supervision of a qualified health professional.
- Advise patient that if a dose is missed, to inject the missed dose as soon as remembered and then inject the next dose at the regularly scheduled time.
- Advise patient to report any of the following to health care provider: intolerable injection site reactions, fatigue, persistent nausea or vomiting, unexplained bruising, bloating, stomach pain, or swelling.
- Instruct patient to stop taking and immediately inform health care provider if yellowing of skin or eyes is noted.
- Instruct diabetic patient to monitor blood glucose more frequently when drug is started or dose is changed and to inform health care provider of significant changes in readings.
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