Pegvisomant

Pegvisomant is indicated for patients who do not tolerate or fail other treatments or for those with extremely elevated insulin-like growth factor I levels. 

Pegvisomant 1 0 mg SQ 40 mg SQ Headache, Liver function tests High IGF-I... 

For patients treated with a GH receptor antagonist, GH levels are not measured because pegvisomant is a modified GH molecule that is detected in commercial GH assays, resulting in falsely... 

Pegvisomant is a growth hormone receptor antagonist registered for the treatment of patients with acromegaly who had insufficient benefit from surgery or radiation. 

Pegvisomant is a GH receptor antagonist that is useful for the treatment of acromegaly. Pegvisomant is the polyethylene glycol (PEG) derivative of a mutant GH, B2036, which has increased affinity for one site of the GH receptor but a reduced... 

Pegvisomant Blocks GH receptors Ameliorates effects of excess GH production Acromegaly SC injection 3-7 x/wk Toxicity Increased liver enzymes... 

Goffin V, Touraine P Pegvisomant. Pharmacia. Curr Opin Investig Drugs 2002 3 752. [PMID 12090548]... 

In 112 patients with active acromegaly who received pegvisomant in a 12 week, randomized, double-blind study of three different daily subcutaneous doses of pegvisomant (10,15, and 20 mg), headache was reported in the placebo group as often as in the active treatment groups (12%) (2). In a longer follow-up study for up to 18 months, 26% of 160 patients had headache, but there was no control group for comparison (3). 

In a 12-week study there was diarrhea in four of 29 patients taking pegvisomant 20 mg/day compared with one patient taking placebo (2). One patient taking 10 mg/day and none taking 15 mg/day reported diarrhea. In a longer follow-up study (18 months) 14% reported diarrhea. 

Two patients developed significantly abnormal liver function tests after receiving pegvisomant for 12 weeks (2,3). Transaminase activities rose to more than 10-fold the upper limits of the reference ranges and returned to normal after withdrawal. One of the two was treated for autoimmune hepatitis (5). Monitoring of liver enzymes every 4-6 weeks is recommended for 6 months or if symptoms of hepatitis develop. 

In a placebo-controlled study, six of 80 patients taking pegvisomant had injection site reactions, which were mild, erythematous, and self-limiting and did not require treatment (2). 

In one patient who switched to pegvisomant, a large aggressive pituitary tumor continued to grow (4). A second patient, who had been treated initially with surgery and then with a dopamine receptor agonist and octreotide LAR for 4 years, switched to pegvisomant for 21 months and subsequently octreotide LAR for 18 months and had stable disease with a tumor volume of 1.33 cm3. When... 

Barkan AL, Burman P, Clemmons DR, Drake WM, Gagel RF, Harris PE, Trainer PJ, van der Lely AJ, Vance ML. Glucose homeostasis and safety in patients with acromegaly converted from long-acting octreotide to pegvisomant. J Clin Endocrinol Metab 2005 90 5684-91. 

Parkinson, C., Kassem, M., Heickendorff, L., et al. PEGvisomant-induced serum insulin-like growth factor-I normalization in patients with acromegaly returns elevated markers of bone turnover to normal. J. Clin. Endocrinol. Metab. 88(12) 5650-5655. 2003. 

Growth hormone requires mediation by somatomedins for many of its actions. These are chiefly formed in the liver, including the important somatomedin C (= insulin-like growth factor 1, IGF-1). Pegvisomant is a newly developed antagonist at the GH receptor and inhibits the production of IGF-1. 

Clinically important, potentially hazardous interactions with alcohol, dimercaprol, ethanolamine, eucalyptus, guanethidine, hydrocortisone, lanreotide, pegvisomant, propranolol, sermorelin, vidarabine, zofenopril... 

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