Growth hormone rebound after cessation of sms 201-995 treatment in acromegaly

We studied a 42-year-old woman who had persistent active acromegaly despite conventional therapies. She was treated for 6 months with SMS 201-995. Her mean plasma growth hormone GH values decreased during treatment from 9.1 +/- 1.2 to 6.6 +/- 1.2 micrograms/L. One month after the withdrawal of SMS 201-995, the plasma GH level increased to 24.4 micrograms/L (P less than 0.001). This elevation was clinically silent and transitory, as GH levels decreased 8 months later to 6.9 +/- 1.3 micrograms/L. Furthermore, at the beginning of therapy, her intractable headache was completely relieved; however, it progressively resumed under therapy. In conclusion, cessation of SMS 201-995 may be followed in some acromegalic patients by a rebound of plasma GH levels. This rebound suggests that SMS 201-995 decreases GH levels by an inhibition of its release from the pituitary. Furthermore, SMS 201-995 may relieve intractable headache in some acromegalic patients, but tolerance to the analgesic effect may develop.