Octreotide acetate
Octreotide acetate (Sandostatin)
Octreotide acetate
(ock- TREE-oh-tyd)
Pregnancy Category: B Sandostatin Sandostatin LAR Depot (Rx)

Classification: Antineoplastic

Action/Kinetics: Similar to the natural hormone somatostatin. It suppresses secretions of serotonin and GI peptides including gastrin, insulin, glucagon, secretin, motilin, vasoactive intestinal peptide, and pancreatic polypeptide. Stimulates fluid and electrolyte absorption from the GI tract and inhibits growth hormone. May alter the absorption of dietary fats in some clients. Rapidly absorbed from injection sites. Peak levels: 5.5 ng/mL after approximately 25 min. t 1/2: 1.7 hr. Duration: Up to 12 hr. About one-third of a dose is excreted unchanged in the urine.

Uses: Metastatic carcinoid tumors and vasoactive intestinal tumors (VIPomas) to inhibit severe diarrhea in both situations and cause improvement in hypokalemia in VIPomas. Acromegaly. The Depot form is used for reduction of growth hormone and IGF-1 acromegaly, the suppression of severe diarrhea and flushing seen with malignant carcinoid syndrome, and treatment of profuse watery diarrhea seen with VIPoma. Investigational: GI fistula, variceal bleeding, pancreatic fistula, irritable bowel syndrome, and dumping syndrome. Also, treatment of diarrhea due to AIDS, short bowel syndrome, diabetes, pancreatic cholera syndrome, chemotherapy or radiation therapy in cancer patients, and idiopathic secretory diarrhea. Other potential uses include enteric fistula, pancreatitis, pancreatic surgery, glucagonoma, insulinoma, Zollinger-Ellison syndrome, intestinal obstruction, local radiotherapy, chronic pain management, antineoplastic therapy, to decrease insulin requirements in diabetes mellitus, in thyrotropin- and TSH-secreting tumors.

Special Concerns: Use with caution in diabetics, in clients with gallbladder disease, in clients with severe renal failure requiring dialysis, and during lactation.

Side Effects: GI: Nausea, diarrhea or loose stools, abdominal pain or distention, malabsorption of fat, vomiting; less commonly, constipation, pancreatitis, anorexia, flatulence, abdominal distention, abnormal stools, hepatitis, jaundice, appendicitis, GI bleeding, hemorrhoids. CNS: Headache, dizziness, lightheadedness, fatigue; less commonly, anxiety, seizures, depression, vertigo, decrease in libido, syncope, tremor, Bell's palsy, paranoia, pituitary apoplexy. CV: Sinus bradycardia in acromegalics, hypertension, thrombophlebitis, SOB, CHF, ischemia, palpitations, orthostatic hypotension, conduction abnormalities, hypertensive reaction, tachycardia, arrhythmias, chest pain. Endocrine: Hyperglycemia or hypoglycemia in acromegalics, biochemical hypothyroidism in acromegalics. Galactorrhea, hypoadrenalism, diabetes insipidus, gynecomastia, amenorrhea, polymenorrhea, vaginitis. Musculoskeletal: Backache, joint pain, arthritis, joint effusion, muscle pain, Raynaud's phenomenon. Dermatologic: Pain, wheal, or erythema at injection site; flushing, edema, pruritus, hair loss, rash, cellulitis, petechiae, urticaria. GU: Pollakiuria, UTI, nephrolithiasis, hematuria. Hematologic: Hematoma at injection site, bruise, iron deficiency anemia, epistaxis. Other: Gallbladder abnormalities, especially stones or biliary sludge; flu symptoms, malabsorption of fat, blurred vision, otitis, allergic reaction, visual disturbances, anaphylactoid reactions, including anaphylactic shock.

Laboratory Test Alterations: Liver enzymes, CK.

Overdose Management: Symptoms: Hyperglycemia and hypoglycemia manifested by dizziness, drowsiness, loss of sensory or motor function, incoordination, disturbed consciousness, and visual blurring. Treatment: Withdraw drug temporarily and treat symptomatically.

Drug Interactions: Octreotide may interfere with drugs such as diazoxide, insulin, beta-adrenergic blocking agents, or sulfonylureas. Close monitoring is necessary.

How Supplied: Injection: 50 mcg/mL, 100 mcg/mL, 200 mcg/mL, 500 mcg/mL, 1000 mcg/mL

Dosage
?SC (Recommended), IV Bolus (Emergencies) Metastatic carcinoid tumors.
Initial, SC: 50 mcg 1-2 times/day. Then, 100-600 mcg/day in two to four divided doses for the first 2 weeks; maintenance, usual: 450 mcg/day (range: 50-1,500 mcg/day).
VIPomas.
Initial, SC: 200-300 mcg/day in two to four divided doses during the initial 2 weeks of therapy (range: 150-750 mcg/day). Doses may then be adjusted but the daily dose usually does not exceed 450 mcg.
Acromegaly.
Initial: 50 mcg t.i.d.; then 100-500 mcg t.i.d. The goal is to achieve growth hormone levels less than 5 ng/mL or IGF-1 levels less than 1.9 U/mL in males and less than 2.2 U/mL in females.
GI fistula.
50-200 mcg q 8 hr.
Variceal bleeding.
25-50 mcg/hr via continuous IV infusion for 18 hr to 5 days.
AIDS-related diarrhea.
100-500 mcg SC t.i.d.
Idiopathic secretory diarrhea, short-bowel syndrome.
Either 25 mcg/hr by IV infusion or 50 mcg SC b.i.d.
Diabetes, pancreatic cholera syndrome, diarrhea due to chemotherapy or radiation therapy in cancer clients.
50-100 mcg SC t.i.d. for 3 days.
Pancreatic fistula.
50-200 mcg q 8 hr.
Irritable bowel syndrome.
100 mcg as a single dose to 125 mcg SC b.i.d.
Dumping syndrome.
50-150 mcg/day.
?Depot Injection Acromegaly, Diarrhea associated with metastatic carcinoid tumors and VIPomas.
20 mg q 4 weeks by intragluteal injection.