Octreotide acetate
Octreotide is a man-made protein that is similar to a hormone in the body called somatostatin. Octreotide lowers many substances in the body such as insulin and glucagon (involved in regulating blood sugar), growth hormone, and chemicals that affect digestion. Octreotide is used to treat acromegaly. Octreotide is also used to reduce flushing episodes and watery diarrhea caused by cancerous tumors (carcinoid syndrome) or tumors called vasoactive intestinal peptide tumors (VIP adenomas).
Mechanism of effect
Octreotide acetate exerts pharmacologic actions similar to the natural hormone, somatostatin. It is an even more potent inhibitor of growth hormone, glucagon, and insulin than somatostatin. Like somatostatin, it also suppresses LH response to GnRH, decreases splanchnic blood flow, and inhibits release of serotonin, gastrin, vasoactive intestinal peptide, secretin, motilin, and pancreatic polypeptide.
Pharmacodynamic
Octreotide substantially reduces and in many cases can normalize growth hormone and/or IGF-1 (somatomedin C) levels in patients with acromegaly.
Pharmacokinetics
After subcutaneous injection, Octreotide is absorbed rapidly and completely from the injection site the volume of distribution (Vdss) was estimated to be 13.6 L, and the total body clearance ranged from 7 L/hr to 10 L/hr.. about 65% was bound in the plasma in a concentration-independent manner. Binding was mainly to lipoprotein and, to a lesser extent, to albumin. The elimination of Octreotide from plasma had an apparent half-life of 1.7 to 1.9 hours .
Dosage
Usual Adult Dose for Carcinoid Tumor Initial dose: 100 to 200 mcg subcutaneously 3 times a day. Maintenance dose: 50 to 300 mcg/day. Maximum dose: 1,500 mcg/day. Usual Adult Dose for Acromegaly Initial dose: 50 mcg subcutaneously 3 times a day. Maintenance dose: 100 to 300 mcg/day.
Drug contraindications
hypersensitivity to drug or its components.Side effects
nausea , abdominal pain , Diarrhea , Dyspnea , thrombocytopenia , hypothyroidism , Infections , Hyperglycemia , Hypoglycemia , GI bleedingInteractions
Trimipramine , Voriconazole , Quinidine , Droperidol , Procainamide , Mefloquine , Indapamide , Arsenic trioxide , Cyclosporine , Glibenclamide , Medroxyprogesterone , Insulin glargine , Flecainide , Bisoprolol , sparfloxacin , vemurafenibAlerts
1-Single doses of Octreotide acetate have been shown to inhibit gallbladder contractility and decrease bile secretion in normal volunteers 2-Octreotide acetate alters the balance between the counter-regulatory hormones, insulin, glucagon and growth hormone, which may result in hypoglycemia or hyperglycemia. 2- Octreotide acetate also suppresses secretion of thyroid stimulating hormone, which may result in hypothyroidism 3- Cardiac conduction abnormalities have also occurred during treatment with Octreotide acetate
Points of recommendation
Careful instruction in sterile subcutaneous injection technique should be given to the patients and to other persons who may administer Octreotide acetate injection.
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