Treatment of acromegaly with octreotide: effectiveness and tolerability of its pulsatile administration by portable pump.

This study was undertaken to evaluate effectiveness and tolerability of octreotide administered in active acromegaly by pulsatile means and compare these data with intermittent three-times-a-day therapy. We studied 13 acromegalics with active disease. All patients received octreotide subcutaneously administered in a pulsatile way using a portable pump delivering 25 micrograms every 120 minutes and in an intermittent way (100 micrograms three times daily) (TID). From pretreatment values (56.5 +/- 13.4 micrograms/L) the 24-h integrated mean GH levels (IC-GH) were significantly reduced both during pulsatile and TID octreotide administration (P < 0.01). IC-GH was significantly lower during pulsatile therapy (17.0 +/- 5.2 micrograms/L) than during TID (22.0 +/- 11.5 micrograms/L; P < 0.05). Before octreotide, IGF-I levels were 669.8 +/- 85.7 micrograms/L; during octreotide therapy they were reduced in 12/13 patients (TID 340.2 +/- 41.5 micrograms/L, pulsatile 338.1 +/- 55.3 micrograms/L; P < 0.01). A correlation between IC-GH and IGF-I levels was observed only during TID administration of octreotide (R = 0.652; P < 0.05). The 24-hour GH pattern fluctuated widely before the start of octreotide therapy. During TID administration, GH levels tended to rise again before the following octreotide injection; this did not occur during pulsatile therapy. Side effects were fewer during pulsatile (15%) than TID (31%) octreotide administration (NS). Asymptomatic gallstones appeared in 1 patient. In conclusion subcutaneous pulsatile octreotide administration in acromegalic patients by means of a small portable pump seems able to produce, a steadier control of GH-IGF-I hypersecretion and fewer side effects than TID administration at same dosage.