Effects of different octreotide dosages on splanchnic hemodynamics and glucagon in patients with TIPS

Late Presentation of Fulminant Necrotizing Enterocolitis in a Child with Hyperinsulinism on Octreotide Therapy

Congenital hyperinsulinism (HI) is the most common cause of persistent hypoglycemia in infants and children. In cases of diazoxide-unresponsive HI, alternative medical and surgical approaches may be required to reduce the risk of hypoglycemia. Octreotide, a somatostatin analog, often has a role in the management of these children, but a dose-dependent reduction in splanchnic blood flow is a recognized complication. Necrotizing enterocolitis (NEC) has been reported within the first few weeks of initiating predominantly high doses of octreotide. We describe the case of an infant with Beckwith-Wiedemann syndrome and diazoxide-unresponsive HI, who had persistent hypoglycemia after two pancreatectomy surgeries. She developed NEC 2 months after beginning octreotide therapy at a relatively low dose of 8 µg/kg/day. This complication has occurred later, and at a lower dose, than has previously been described. We review the case and identify the known and suspected multifactorial risk factors for NEC that may contribute to the development of this complication in patients with HI.

Prediction of octreotide efficacy by electrogastrography in the treatment of patients with esophageal variceal hemorrhage

Our aim is to investigate the significance of electrogastrography in the treatment of esophageal variceal hemorrhage with octreotide. Electrogastrography was performed in patients with esophageal variceal hemorrhage before and during the treatment consisting of various doses of octreotide (25 ug h(-1) group and 50 ug h(-1) group). The dominant power of electrogastrography and its relationship with the hemostatic efficacy of octreotide treatment were evaluated. Dominant power of electrogastrography decreased significantly during treatment with octreotide (P < 0.05). The reduction in the amplitude of dominant power in the 50 ug h(-1) group was significantly larger than in the 25 ug h(-1) group (P < 0.05), and it was correlated with hemostatic efficacy of octreotide treatment. We conclude that octreotide treatment in patients with esophageal variceal hemorrhage can result in a significant decrease of dominant power, which correlates with the hemostatic efficacy of octreotide, so the change of dominant power could be used as a predictor of evaluating the treatment efficacy of octreotide in esophageal variceal hemorrhage patients.

"Splenic artery steal syndrome" is a misnomer: the cause is portal hyperperfusion, not arterial siphon

Splenic artery embolization (SAE) improves hepatic artery (HA) flow in liver transplant (OLT) recipients with so-called splenic artery steal syndrome. We propose that SAE actually improves HA flow by reducing the HA buffer response (HABR). Patient 1: On postoperative day (POD) 1, Doppler ultrasonography (US) showed patent vasculature with HA resistive index (RI) of 0.8. On POD 4, aminotransferases rose dramatically; his RI was 1.0 with no diastolic flow. Octreotide was begun, but on POD 5 US showed reverse diastolic HA flow with no signal in distal HA branches. After SAE, US showed markedly improved flow, RI was 0.6, diastolic flow in the main artery, and complete visualization of all distal branches. By POD 6, liver function had normalized. RI in the main HA is 0.76 at 2 months postsurgery. Patient 2: On POD 1, RI was 1.0. US showed worsening intrahepatic signal, with no signal in the intrahepatic branches and reversed diastolic flow despite good graft function. On POD 7, SAE improved the intrahepatic waveform and RI (from 1.0 to 0.72). Patient 3: Intraoperative reverse diastolic arterial flow persisted on PODs 1, 2, and 3, with progressive loss of US signal in peripheral HA branches. SAE on POD 4 improved the RI (0.86) and peripheral arterial branch signals. Patient 4: US on POD 1 showed good HA flow with a normal RI (0.7). A sudden waveform change on POD 2 with increasing RI (0.83) prompted SAE, after which the wave form normalized, with reconstitution of a normal diastolic flow (RI 0.68). In conclusion, these reports confirm the usefulness of SAE for poor HA flow but suggest that inflow steal was not the problem. Rather than producing an increase in arterial inflow, SAE worked by reducing portal flow and HABR, thereby reducing end-organ outflow resistance. Evidence of this effect is the marked reduction of the RI after the SAE to 0.6, 0.72, 0.86, and 0.68, in patients 1-4, respectively. SAE reduces excessive portal vein flow and thereby ameliorates an overactive HABR that can cause graft dysfunction and ultimately HA thrombosis.

Effect of propranolol and depot lanreotide SR on postprandial and circadian portal haemodynamics in cirrhosis

BACKGROUND

Long-acting somatostatin analogues have been suggested as an alternative to propranolol for the prevention of variceal rebleeding.

AIM

To compare the effectiveness of lanreotide SR, a new depot formulation injected once-weekly, and propranolol in reducing circadian portal blood flow (PVF) and meal-stimulated hepatic venous pressure gradient (HVPG) in patients with liver cirrhosis.

METHODS

Patients were randomized to receive either lanreotide SR intramuscularly (30 mg once weekly, n=12) or propranolol (n=12) orally. Hemodynamic measurements were performed on day 0 and on day 21 after a 3-week period of drug administration, while patients received three standard oral liquid test meals. On each study day 27 PVF measurements were performed over 24 h and eight measurements of HVPG during the first postprandial period.

RESULTS

Propranolol was more effective than lanreotide SR in reducing baseline HVPG (-21.9 vs. -13.6%, P=0.04) and meal-stimulated HVPG (-16.6 vs. -3.8%, P=0.04). Propranolol reduced circadian PVF significantly by 9.3% (P=0.03) but not lanreotide SR.

CONCLUSIONS

Long-term treatment with propranolol reduced baseline and postprandial HVPG and circadian PVF, while lanreotide SR did not. The results of our study do not encourage clinical testing of lanreotide SR 30 mg for the prevention of variceal haemorrhage.

Octreotide in hepatorenal syndrome: a randomized, double-blind, placebo-controlled, crossover study

The hepatorenal syndrome (HRS) is related to vasoconstriction of the renal cortex induced by systemic hypovolemia that follows splanchnic vasodilatation as the primary event in the cascade of hemodynamic changes associated with portal hypertension. We evaluated the effects of octreotide, a splanchnic vasoconstrictor, on HRS in cirrhotic patients. We compared the effects of octreotide infusion (50 microg/h) to placebo using a randomized, double-blind, cross-over design over 2, 4-day periods. Nineteen patients were included, and 14 patients could complete the 2 phases of the study (group 1: placebo first; n = 8 and group 2: octreotide first; n = 6) The end point of the study was to evaluate improvement in renal function as defined by a 20% decrease in serum creatinine value after a 4-day treatment as compared with baseline. In all the patients, a normal central venous pressure was maintained by daily intravenous administration of 2 units of albumin. The 2 groups were similar with regard to demographic data and liver and kidney function parameters at baseline. Improvement in renal function was observed in 2 patients after the placebo and 1 patient after octreotide infusion in group 1 and in 2 patients after octreotide infusion and 1 patient after placebo in group 2 (P = not significant). In addition, treatment with octreotide infusion did not result in significant changes in creatinine clearance, daily urinary sodium, plasma renin activity, plasma aldosterone and glucagon levels, or renal and mesenteric artery resistance indices as measured by Doppler ultrasonography. In conclusion, the present study demonstrates that, under our experimental conditions, octreotide infusion combined with albumin is not effective for the treatment of HRS in cirrhotic patients.

Peroral absorption of octreotide in pigs formulated in delivery systems on the basis of superporous hydrogel polymers

PURPOSE

The aim of this study was to investigate the enhancement of peroral octreotide absorption using delivery systems based on superporous hydrogel (SPH) and SPH composite (SPHC) polymers.

METHODS

Six female pigs (BW of 23.5 kg) were used in this study. SPH-based delivery systems were made of two components: 1) a conveyor system made of SPH and SPHC; 2) a core that contained octreotide. The core was inserted into the conveyor system (core inside, c.i.) or attached to the surface of the conveyor system (core outside, c.o.). Four different peroral formulations were investigated: c.i., c.o., core outside including trimethyl chitosan chloride (c.o.t.), and octreotide only in the absence of any polymer (o.o.). All formulations were placed in enteric-coated gelatin capsules (size 000) and administered perorally. Intravenous administration was used to determine bioavailability (F) values. Blood samples taken from the cannulated jugular vein were analyzed by radioimmunoassay.

RESULTS

Peroral administration of 15 mg o.o. resulted in low F values of 1.0 +/- 0.6% (mean +/- SEM) whereas c.i. and c.o. administrations resulted in remarkably higher F values of 12.7 +/- 3.6% and 8.7 +/- 2.4%, respectively. By the addition of trimethyl chitosan chloride as an extra absorption enhancer to c.o.t., the highest bioavailability (16.1 +/- 3.3%) was achieved.

CONCLUSIONS

These novel delivery systems based on SPH and SPHC polymers are able to increase the peroral bioavailability of octreotide by mechanical fixation and increasing the retention of the dosage form at the absorption site.