Dependency and analgesia related to treatment with subcutaneous octreotide in patients with growth hormone-secreting tumors.

OBJECTIVE: To describe three patients diagnosed with somatotropinomas in whom the analgesic effect of octreotide was observed, along with dependency to the drug.
METHODS: These patients had pituitary macroadenomas treated with transphenoidal surgery and pituitary radiotherapy, and received high daily doses (>900 microg/day) of subcutaneous octreotide because of persistent high levels of growth hormone and insulin-like growth factor I (IGF-I).
RESULTS: Headache occurred prior to drug administration in all three cases, with relief soon after. We also observed tolerance to octreotide's analgesic and anti-secretory actions (one patient), craving for the drug (two patients), withdrawal syndrome (one patient), and drug abuse (one patient).
CONCLUSION: Dependency syndrome may occur when high doses of octreotide are used, sometimes leading to drug abuse. Tolerance to the growth hormone anti-secretory effect of the drug may encourage physicians to increase doses to levels at which drug dependency has been observed. Sustained release somatostatin analogs may represent a solution to this problem.