Octreotide dosing

Harris AG, O Dorisio TM, Weltering EA, et al. Consensus statement Octreotide dose titration in secretory diarrhea. Diarrhea Management Conference. Dig Dis Sci 1995 40 1464-1473. 

Use of the first-generation somatostatin analog octreotide is limited by its extremely short duration of action and requirement for subcutaneous administration at least three times a day. If a patient s GH level returns to baseline before the end of an 8-hour dosing interval, the frequency of octreotide administration can be increased to every 4 to 6 hours. Most patients require octreotide in doses of 100 to 200 meg three times daily.19,20 To improve patient tolerance to gastrointestinal (GI) adverse effects, start octreotide at 50 meg every 8 hours.20 Assess IGF-I serum concentrations every 2 weeks after initiating therapy to further titrate dose in increments of 50 meg per dose. 

In some patients SIBO is caused by intestinal stasis secondary to motility defects, and the restoration of normal intestinal motility may represent an effective approach. Prokinetic agents have been shown to improve intestinal motility [ 15,16], and the use of this therapeutic approach has been shown to be effective in patients with scleroderma, low-dose octreotide proved to be useful in the reduction of bacterial overgrowth [17]. Unfortunately, cisapride was recently removed from the market due to car-diotoxicity, and, apart from an erythromycin analog without antibiotic effects which showed no effects in rats [18],... 

Van Der Hoek, J.,De Herder, W. W., Feelders, R. A., Van Der Lely, A. J. and Lamberts, S. W. A single-dose comparison of the acute effects between the new somatostatin analog SOM230 and octreotide in acromegalic patients. J. Clin. Endocrinol. Metab. 89 638-645,2004. 

Population PK analysis following a single dose of 30 mg microencapsulated octreotide acetate intramuscularly the PK profile of microencapsulated octreotide acetate was effectively described by the derived population model. The relationship between IGF-1 and drug concentration could be used to guide optimization of therapeutic octreotide dosage regimens... 

Recommended dosage and monitoring requirements Sandostatin injectable solution is usually administered subcutaneously in initial doses of 50 to 100 pg two or three times daily. Upward dose titration is frequently required. Sandostatin LAR Depot injectable suspension should never be administered intravenously or subcutaneously. Patients not currently receiving octreotide acetate should begin therapy with subcutaneous injections and then can be switched to the depot injection of 20mg intragluteally at 4-week intervals for 3 months. 

Pharmacokinetics After subcutaneous injection, octreotide is absorbed rapidly and completely from the injection site intravenous and subcutaneous doses were... 

Dispostion About 32% of the dose of octreotide is excreted unchanged into the urine. Octreotide is also metabolized by the fiver. 

Octreotide acetate injectable long-acting suspension is a slow-release microsphere formulation. It is instituted only after a brief course of shorter-acting octreotide has been demonstrated to be effective and tolerated. Injections into alternate gluteal muscles are repeated at 4-week intervals in doses of 20-40 mg. 

A dopamine agonist alone or in combination with pituitary surgery, radiation therapy, or octreotide administration can be used to treat acromegaly. The doses required are higher than those used to treat hyperprolactinemia. For example, patients with acromegaly require 20-30 mg/d of bromocriptine and seldom respond adequately to bromocriptine alone unless the pituitary tumor secretes prolactin as well as GH. 

Octreotide inhibits intestinal secretion and has dose-related effects on bowel motility. In low doses (50 meg subcutaneously), it stimulates motility, whereas at higher doses (eg, 100-250 meg subcutaneously), it inhibits motility. Octreotide is effective in higher doses for the treatment of diarrhea due to vagotomy or dumping syndrome as well as for diarrhea caused by short bowel syndrome or AIDS. Octreotide has been used in low doses (50 meg subcutaneously) to stimulate small bowel motility in patients with small bowel bacterial overgrowth or intestinal pseudo-obstruction secondary to scleroderma. 

Octreotide, an octapeptide somatostatin analogue, is usually given subcutaneously in three divided doses per day. Longer-acting analogues, such as lanreotide, with similar efficacy and adverse effects to octreotide, but which can be given every 14-28 days, have been developed (1,2). The therapeutic indications and adverse effects of octreotide have been reviewed (SEDA-13,1309 3). 

A review of octreotide LAR has suggested that the most common adverse effects are gastrointestinal effects and injection site reactions (4). Injection site pain is also common and dose related. The cardiovascular, biliary, and glucose metabolism effects were also reviewed. 

One of 10 patients with rheumatoid arthritis in an open study stopped using long-acting octreotide because of severe diarrhea and weight loss of 3 kg (34). These effects are dose-related and are similar in healthy volunteers, acromegalic patients, and patients with gastrointestinal tumors (3). 

Ursodiol appeared to reverse gall-bladder abnormalities in seven of 10 patients. Data from this study also showed earlier development of sludge in recipients of higher doses of octreotide (37). 

B6. Beechey-Newman, N., Controlled trial of high-dose octreotide in treatment of acute pancreatitis. Dig. Dis. Sci. 38, 644-647 (1993). 

Fig. 2 The influence of Sandostatin LAR biodegradable depot formulation on the mean plasma growth hormone concentrations in humans. Plasma concentrations are shown over a 24 hour period 28 days after administration of a second monthly 20mg dose of Sandostatin LAR, . For comparison, plasma concentrations are provided for untreated controls, , and for patients receiving multiple daily subcutaneous octreotide injections, A. (From Refs. ° ° l)...

The somatostatin analog octreotide can decrease gastric acid secretion. In one report, octreotide, given s.c. to horses at dose rates of 0.1,0.5,1.0 and 5.0 xg/kg, increased gastric pH to >5.0 compared with baseline values (consistently <2.7) (Rabon Reuben 1990). The duration of effect was dose dependent and ranged from 2.4 to 5.4 h. 

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