Somatostatin or octreotide versus endoscopic sclerotherapy in acute variceal haemorrhage: a meta-analysis study

[Somatostatin and the digestive system. Clinical experiences]

The effect of somatostatin on the gastrointestinal tract is complex; it inhibits the release of gastrointestinal hormones, the exocrine function of the stomach, pancreas and bile, decreases motility and influences absorption as well. Based on these diverse effects there was an increased expectation towards the success of somatostatin therapy in various gastrointestinal disorders. The preconditions for somatostatin treatment was created by the development of long acting somatostatin analogues (octreotide, lanreotide). During the last twenty-five years large trials clarified the role of somatostatin analogues in the treatment of various gastrointestinal diseases. This study summarizes shortly these results. Somatostatin analogue treatment could be effective in various pathological conditions of the gastrointestinal tract, however, this therapeutic modality became a part of the clinical routine only in neuroendocrine tumours and adjuvant treatment of oesophageal variceal bleeding and pancreatic fistulas.

Octreotide for acute esophageal variceal bleeding: a meta-analysis

BACKGROUND & AIMS

Studies of octreotide have not demonstrated a consistent benefit in efficacy or safety compared with conventional therapies. This study statistically pooled existing trials to evaluate the safety and efficacy of octreotide for esophageal variceal hemorrhage.

METHODS

We identified randomized trials of octreotide for variceal hemorrhage from computerized databases, scientific meeting abstracts, and the manufacturer of octreotide. Blinded reviewers abstracted the data, and a meta-analysis was performed.

RESULTS

Octreotide improved control of esophageal variceal hemorrhage compared with all alternative therapies combined (relative risk [RR], 0.63; 95% confidence interval [CI], 0.51-0.77); vasopressin/terlipressin (RR, 0.58; 95% CI, 0.42-0.81); or no additional intervention/placebo (among patients that received initial sclerotherapy/banding before randomization) (RR, 0.46; 95% CI, 0.32-0.67). Octreotide had comparable efficacy to immediate sclerotherapy for control of bleeding (RR, 0.94; 95% CI, 0.55-1.62), fewer major complications than vasopressin/terlipessin (RR, 0.31; 95% CI, 0.11-0.87), and a complication profile comparable to no intervention/placebo (RR, 1.06; 95% CI, 0.72-1.55). No specific alternative therapy demonstrated a mortality benefit.

CONCLUSIONS

These results favor octreotide over vasopressin/terlipressin in the control of esophageal variceal bleeding and suggest it is a safe and effective adjunctive therapy after variceal obliteration techniques. Trials are needed to determine the optimal dose, route, and duration of octreotide treatment.

Early administration of vapreotide for variceal bleeding in patients with cirrhosis

BACKGROUND

In patients with cirrhosis, pharmacologic or endoscopic treatment may control variceal bleeding. However, the effects of early administration of a somatostatin analogue followed by endoscopic treatment are unknown.

METHODS

We studied the effects of treatment with vapreotide, a somatostatin analogue, begun before endoscopic treatment in 227 patients with cirrhosis who were hospitalized for acute upper gastrointestinal bleeding. The patients were randomly assigned to receive vapreotide (a 50-microg intravenous bolus followed by an infusion at a rate of 50 microg per hour for five days) or placebo within a mean (+/-SD) of 2.3+/-1.5 hours after admission. All the patients received endoscopic treatment a mean of 2.6+/-3.3 hours after the infusion was begun. After the exclusion of 31 patients whose bleeding was not caused by portal hypertension, there were 98 patients in each group.

RESULTS

At the time of endoscopy, active bleeding was evident in 28 of 91 patients in the vapreotide group (31 percent), as compared with 43 of 93 patients in the placebo group (46 percent) (P=0.03). During the five-day infusion, the primary objective--survival and control of bleeding--was achieved in 65 of 98 patients in the vapreotide group (66 percent) as compared with 49 of 98 patients in the placebo group (50 percent) (P=0.02). The patients in the vapreotide group received significantly fewer blood transfusions (2.0+/-2.2 vs. 2.8+/-2.8 units, P=0.04). Overall mortality rates at 42 days were not significantly different in the two groups.

CONCLUSIONS

In patients with cirrhosis and variceal bleeding, the combination of vapreotide and endoscopic treatment is more effective than endoscopic treatment alone as a method of controlling acute bleeding. However, the use of combination therapy does not affect mortality rates at 42 days.

Somatostatin or octreotide in acute variceal bleeding

In patients with cirrhosis, somatostatin or octreotide administration is followed by a transient decrease in the hepatic venous pressure gradient and azygos blood flow. Although no clear-cut changes in variceal pressure are observed and the exact mechanisms of acute hemodynamic changes induced by somatostatin or its derivatives are still unknown, this provided the rationale for its use in patients with variceal hemorrhage. The only known sustained hemodynamic effect of octreotide is to prevent increases in hepatic venous gradient or azygos blood flow in response to food intake. Somatostatin infusion can be as effective as sclerotherapy in the initial control of bleeding esophageal varices in patients with cirrhosis and is associated with fewer complications. Octreotide also seems to be as effective as endoscopic therapy in the control of acute variceal bleeding, although larger studies should be performed before its efficacy and safety profile can be fully evaluated. The combination of somatostatin or long-acting analogues to endoscopic therapy has recently been delineated as one of the most promising approaches in these patients. Early somatostatin administration with repeat boluses, starting several hours before sclerotherapy is combined, eases the endoscopic procedure and reduces bleeding control failure rate. Although two studies also showed that octreotide, when started at the time of sclerotherapy or variceal banding, also improves bleeding control, a conclusion on octreotide use in these patients is premature. Optimal administration schedules and doses of somatostatin or octreotide are still unknown. The safety of octreotide in patients with variceal bleeding, which has recently been challenged, should be assessed in larger trials. Recent data suggesting that octreotide combination to beta-blockers or sclerotherapy may represent a useful approach for long-term prevention of rebleeding in these patients will have to be confirmed.

Update on upper gastrointestinal bleeding. Basing treatment decisions on patients' risk level

Acute upper gastrointestinal bleeding is a common reason for hospitalization. Mortality rates range from 5% to 15%; patients with severe comorbidities and those with persistent or recurrent bleeding are at highest risk. Accurate preliminary risk assessment and resuscitation can proceed simultaneously at initial presentation. Risk assessment can guide treatment decisions. Early upper gastrointestinal endoscopy, a cornerstone of management, allows for rapid diagnosis, application of endoscopic therapy, and completion of risk assessment. Endoscopic therapy can alter the natural history of upper gastrointestinal bleeding by reducing rates of further bleeding and, consequently, mortality. Complete risk assessment of both clinical and endoscopic factors can likely result in shorter hospital stays and improved outcomes. Early assessment helps identify low-risk patients in whom discharge on the day of presentation is appropriate.

Altered kinetics and extent of urinary daidzein and genistein excretion in women during chronic soya exposure

Soybean consumption may be protective for breast cancer, possibly due in part to the presence of the isoflavones daidzein and genistein, which are weakly estrogenic. The metabolism and disposition of these phytoestrogens during chronic soya exposure were studied on a metabolic unit. Six healthy 22- to 29-year-old women consumed an unrestricted hospital diet for most of the study and ingested 12 oz of soymilk with each meal for one month. At two-week intervals, excretion of isoflavones in urine was studied, during which time the subjects consumed a constant basal diet for three to four days, ingested the full daily 36-oz portion of soymilk within 30 minutes each day for one to two days, and collected urine continuously. Urinary recovery of genistein [initially 23.9 +/- 17.3% (SD) of ingested genistin + genistein], daidzein (initially 66.2 +/- 23.5% of ingested daidzin + daidzein), and equol (initially 28% of the ingested precursors daidzin + daidzein in 1 subject and < 1% in 5 subjects) decreased progressively over four weeks of daily soya ingestion by 42% for genistein (p < 0.05) and 31% for daidzein (p < 0.01) but increased by 3- to 100-fold for equol (4 subjects, p < 0.05). Total amounts excreted and peak levels were similarly affected. The absorption half-lives (t 1/2) for genistein and daidzein were initially 2.7 +/- 0.8 and 1.6 +/- 0.5 hours, respectively, and during four weeks of soymilk ingestion decreased to 2.0 +/- 0.6 (p = 0.04) and 1.4 +/- 0.2 hours (p = 0.06), respectively, suggesting more rapid absorption. The appearance t 1/2 of equol can be estimated for only one subject initially (2.9 hrs), but during four weeks of soya ingestion it could be estimated for three more subjects (4.7 +/- 2.3 hrs). The excretion t 1/2 values for genistein and daidzein were initially 6.7 +/- 0.8 and 4.4 +/- 0.7 hours, respectively, and during four weeks of soymilk ingestion decreased to 4.2 +/- 1.2 (p = 0.005) and 3.2 +/- 1.1 hours (p = 0.005), respectively, suggesting more rapid excretion. For equol, the excretion t 1/2 was initially 9.1 hours (1 subject), and after two and four weeks of soymilk ingestion it was 13.4 +/- 9.7 and 5.5 +/- 1.6 hours (4 subjects, p = 0.046, 2 wks vs. 4 wks), respectively. These results indicate that metabolism and disposition of ingested isoflavones are altered during chronic soya ingestion in women, perhaps from increased metabolic degradation to formation of nonisoflavone metabolites. Increased production of the longer- and stronger-acting estrogenic equol in some women during chronic soymilk ingestion may alter the estrogenic potency of dietary soya isoflavones.