Medical treatments for acromegaly
| Medication | Dose | Normalization of IGF-1 | Reduction of tumor size | Comments |
|---|---|---|---|---|
| Somatostatin receptor ligands (SRLs) | ||||
| Octreotide | Starting dose 50 mg subcutaneously every 8 hours; can be increased every 2 weeks, usually up to 300 mg per day | 30%–40% | Arrested growth or reduced tumor size in about 50% | Endocrine Society guidelines recommend use of either an SRL or pegvisomant as the initial adjuvant medical therapy. In patients with large tumors abutting the optic chiasm, an SRL is preferred as pegvisomant does not suppress tumor growth. An SRL is used as primary therapy in patients who cannot be cured by surgery, have extensive cavernous sinus invasion, have no chiasmal compression, or are poor surgical candidates. |
| Octreotide long-acting release | 10–40 mg intramuscularly every 4 weeks | 30%–40% | ||
| Lanreotide depot/autogel | 60–120 mg deeply subcutaneous every 4 weeks | 30%–40% | Arrested growth or reduced tumor size in about 50% | |
| Pasireotide | 40–60 mg intramuscularly every 28 days | About 35% | Arrested growth or reduced tumor size in about 50% | A novel SRL with enhanced binding to more somatostatin receptors than the other SRLs. Associated with hyperglycemia in 57% of patients (see Table 3). |
| Human GH receptor antagonist | ||||
| Pegvisomant | 10–40 mg subcutaneously daily | 63% | Usually, no change, but tumor growth may occur in 3%–5% of patients | Can be combined with an SRL. IGF-1 but not GH should be used as a marker of efficacy. Improves glycemic control, useful when comorbid diabetes mellitus is present. Very expensive. |
| Dopamine agonist | ||||
| Cabergoline | 1–4 mg by mouth weekly | 20%–30% | No change | Can be an initial adjuvant therapy in patients with modest elevations of IGF-1 and GH, with or without concomitant hyperprolactinemia, and with mild signs and symptoms of acromegaly. Can be used in combination with an SRL or pegvisomant. Therapeutic response tends to decrease with time. |
GH = growth hormone; IGF-1= insulin-like growth factor 1
Based on information from references 14 and 15.