Comparison of six months therapy with octreotide versus lanreotide in acromegalic patients: a retrospective study

OBJECTIVE We analysed the effects of 6-months' treatment with octreotide s. c, and lanreotide-SR on circulating GH and IGF-I levels in acromegaly. DESIGN Open retrospective study. PATIENTS Thirty-eight patients with active acromegaly (plasma IGF-I levels greater than 2 standard deviations for age-matched controls and increased s erum GH levels not suppressible by oral glucose load) were studied. All pat ients received s.c, octreotide at a dose of 150-600 mu g/day for six months as first therapy and subsequently, lanreotide i.m., 30-60 mg either at 14 or 10 day intervals, for 6 months. A 3 months' washout was applied before s tarting lanreotide treatment. MEASUREMENTS Mean serum GH levels (from three samples), IGF-I, and clinical examination were performed before and 30, 60, 90 and 180 days after octreo tide and lanreotide treatments. Safety tests, HbA1c and, thyroid function w ere evaluated every three months. RESULTS Circulating GH and IGF-I levels were significantly reduced (P<0.001 ) after one, three and six months of both octreotide and lanreotide treatme nt. The absolute values were lower and the percent decrease in serum GH lev els obtained after octreotide treatment was significantly greater, at all s cheduled assessments, than after lanreotide (P<0.01). Serum IGF-I levels du ring octreotide were significantly lower only after the first month of ther apy (P<0.01). CONCLUSIONS Our study shows that octreotide s.c, is able to induce an earli er reduction in IGF-I levels and a more marked reduction in GH levels than lanreotide. However, after six months of therapy the number of patients wit h safe GH levels and normal IGF-I age-matched levels, was similar with both drugs. Therefore we suggest that octreotide treatment be preferentially us ed in the short-term presurgical treatment, while lanreotide can be used in chronic therapy when better compliance is necessary.