Slow-release lanreotide and octreotide LAR in the medical therapy of acromegaly

The first line of treatment for active acromegaly is still neurosurgery followed by radiotherapy. Octreotide (1), slow-release (SR) lanreotide (2) and octreotide LAR (3) are currently administered before surgery or in patients in whom surgery and/or radiotherapy have failed to restore normal growth hormone (GH)/insulin-like growth factor-I (IGF-I) levels. Cozzi et al. (4) have recently shown that octreotide LAR, a somatostatin analogue to be administered at 28-day intervals, seems to be more efficacious than SR lanreotide, a somatostatin analogue administered at intervals ranging from 10 to 14 days. This observation seems quite surprising, as previous studies comparing effectiveness and tolerability of the different somatostatin analogue formulations did not show significant differences. Colao et al. (5) observed that SR lanreotide treatment in 45 patients seemed to be just as efficacious as octreotide and to cause a similar incidence of side effects. In the European multicentre study, Lancranjan et al. (3) reported that monthly intramuscular administration of octreotide was at least as effective, well tolerated and safe as octreotide therapy of three daily subcutaneous injections. In a preliminary study, we did not observe significant differences in GH/IGF-I control in 5 patients who were switched from SR lanreotide to octreotide LAR (6). In Cozzi’s paper (4), 12 acromegalic patients (6 men and 6 women; aged 28–76 years) with active disease on chronic SR lanreotide (injections every 7–21 days) treatment (6–24 months) were switched directly to treatment with octreotide LAR (10–30 mg). Data collected on stabilised SR lanreotide treatment were compared after 3 and 6 months of octreotide LAR therapy. Cozzi et al. (4) reported normal GH levels (<2.5 mg/l) in 1 and 4 patients after SR lanreotide and octreotide LAR respectively, while age-adjusted IGF-I levels were normal in 4 and 5 patients respectively. We analysed our data obtained in 12 acromegalic patients (5 men and 7 women; age range 28–75 years) in whom long-term (6–30 months) SR lanreotide treatment (30 mg every 7–20 days) was changed to treatment with octreotide LAR (20–30 mg) without a wash-out period. Data obtained after the first 6–12 months on the two therapies are reported in Table 1. Samples were collected before the following injection. European Journal of Endocrinology (2000) 142 697–698 ISSN 0804-4643