octreotide acetate

Action

Suppresses secretion of serotonin, serotonin metabolites, and gastrohepatic peptides, increasing fluid and electrolyte absorption from GI tract. Also suppresses growth hormone, insulin, and glucagon.

Availability

Depot injection: 10 mg, 20 mg, 30 mg

Injection: 0.05 mg/ml, 0.1 mg/ml, and 0.5 mg/ml in 1-ml ampules; 0.2 mg/ml and 1 mg/ml in 5-ml vials

Indications and dosages

➣ Diarrhea and flushing associated with carcinoid tumors

Adults: 100 to 600 mcg (Sandostatin) subcutaneously or I.V. daily in two to four divided doses for 2 weeks. Then, depending on response, 20 mg (LAR Depot) I.M. q 4 weeks for 2 months.

➣ Diarrhea caused by vasoactive intestinal peptide tumors (VIPomas)

Adults: 200 to 300 mcg (Sandostatin) subcutaneously or I.V. daily in two to four divided doses for 2 weeks. Then, depending on response, 20 mg (LAR Depot) I.M. q 2 weeks for 2 months.

➣ Acromegaly

Adults: 50 to 100 mcg (Sandostatin) subcutaneously or I.V. two or three times daily. Then, depending on response, 20 mg (LAR Depot) I.M. q 4 weeks for 3 months. Then adjust based on growth hormone levels.

Dosage adjustment

• Renal impairment

Off-label uses

• Dumping syndrome (postprandial hypotension)

• GI and pancreatic fistulas

• Variceal bleeding

Contraindications

• Hypersensitivity to drug or its components

Precautions

Use cautiously in:

• gallbladder disease, renal impairment, hyperglycemia or hypoglycemia, fat malabsorption

• pregnant or breastfeeding patients

• children.

Administration

• When giving subcutaneously, rotate administration site with each injection.

See Don't give LAR Depot I.V.

• Mix I.M. solution and inject deep into gluteal muscle over 3 minutes. Don't use deltoid.

• For I.V. administration, dilute in 50 to 200 ml of dextrose 5% in water or normal saline solution. Infuse over 15 to 30 minutes.

• Know that octreotide suppression test and octreotide scintigraphy may be done to determine if drug will aid carcinoid tumor treatment.

• Drug may be kept at room temperature for 2 weeks. Refrigerate ampules.

Adverse reactions

CNS: dizziness, drowsiness, fatigue, headache, weakness

CV: edema, bradycardia, conduction abnormalities, arrhythmias

EENT: vision disturbances

GI: nausea, vomiting, diarrhea, abdominal pain, cholelithiasis, fat malabsorption

Skin: flushing

Metabolic: hypothyroidism, hyperglycemia, hypoglycemia

Other: injection site pain

Interactions

Drug-drug. Cyclosporine: reduced cyclosporine blood level

Insulin, oral hypoglycemics: altered requirements for these drugs

Orally administered drugs: altered absorption of these drugs

Drug-diagnostic tests. Glucose: increased or decreased level

Hepatic enzymes: slightly increased levels

Schilling's test: abnormal results

Thyroxine, vitamin B₁₂: decreased levels

Drug-food. Fats: altered octreotide absorption

Patient monitoring

• Assess bowel sounds and stool frequency and consistency.

• Monitor vital signs and fluid intake and output. Stay alert for dehydration or edema.

• Evaluate diabetic patient for hypoglycemia or hyperglycemia.

• Know that in women with active acromegaly, normalization of growth hormone and insulin-like growth factor-1 may restore fertility.

Patient teaching

• Tell patient being treated for carcinoid tumor to keep track of number of daily stools or flushing episodes.

• Instruct patient to weigh himself daily and report significant changes.

• Advise female with childbearing potential to use adequate contraception while taking drug.

• If patient will use drug at home, teach correct methods for injection, storage, and needle disposal.

• Caution patient to avoid driving and other hazardous activities until he knows how drug affects concentration, vision, and alertness.

• As appropriate, review all other significant and life-threatening adverse reactions and interactions, especially those related to the drugs, tests, and foods mentioned above.