Octreotide

Indications

Octreotide is used for: Acromegaly, Variceal haemorrhage, Secretory neoplasms, Following pancreatic surgery, HIV-associated diarrhoea

Adult Dose

Acromegaly Solution: 50 mcg SC q8hr initially; titrate up to 500 mcg SC q8hr if necessary; after successful treatment with solution for 2 weeks, initiate treatment with suspension (depot injection) Suspension (depot injection): 20 mg IM (gluteal) every 4 weeks for 3 months; titrate up or down to 10-30 mg IM every 4 weeks, depending on response; not to exceed 40 mg, as follows Symptoms controlled: If GH < 1 ng/mL and IGF-1 normal, decrease dose to 10 mg IM every 4 weeks; if GH < 2.5 ng/mL and IGF-1 normal, maintain dose at 20 mg IM every 4 weeks Symptoms uncontrolled: If GH > 2.5 ng/mL or IGF-I elevated, increase dose to 30 mg IM every 4 weeks; if symptoms persist, increase to 40 mg IM Carcinoid Tumor Solution: 100-600 mcg/day SC divided q6-12hr; may titrate to 1500 mcg/day; after successful treatment with solution for 2 weeks, initiate treatment with suspension (depot injection) Suspension (depot injection): 20 mg IM every 4 weeks if regular injection well tolerated Subcutaneous Prophylaxis of complications following pancreatic surgery Adult: 100 mcg tid of a rapid-acting preparation given for 7 consecutive days, starting at least 1 hr before operation. HIV-associated diarrhoea Adult: Initial dose 100 mcg tid. If symptoms are not controlled after 1 wk, increase dose to 500 mcg tid. Intravenous Variceal haemorrhage in patients with cirrhosis Adult: As continuous IV infusion: 25 mcg/hr for 48 hr (up to 5 days in patients at high risk of re-bleeding). Hepatic impairment: Cirrhosis, 10 mg IM every 4 weeks initially, then titrate to effect

Child Dose

Safety and efficacy not established

Renal Dose

Renal impairment: Without dialysis, dose adjustment not necessary; with dialysis, 10 mg IM every 4 weeks initially, then titrate to effect

Administration

IV Preparation Common diluent: 50-100 ?g/50 mL NS Common diluent for continuous IV infusion: 1200 ?g/250 mL NS Minimum volume: 50 mL NS IV/IM Administration IM Administer suspension (depot injection) immediately after reconstitution; inject into gluteal muscle, avoiding deltoid IV IV administration may be IVP, IVPB, or continuous infusion Regular injection only: IVP should be administered undiluted over 3 minutes IVPB: Administer over 15-30 minutes Continuous infusion: 25-50 ?g/hr for treatment of esophageal variceal bleeding

Contra Indications

Hypersensitivity.

Precautions

Renal disease; risk of gall bladder disease; DM; hypothyroidism. Pregnancy, lactation, children, elderly. Monitor levels of vitamin B12 during long term therapy. Lactation: Whether octreotide crosses into breast milk is not known; avoid giving to lactating women

Pregnancy-Lactation

Interactions

Dosage adjustment of concurrent therapy may be necessary with calcium channel blockers, oral hypoglycaemics, ?-blockers, diuretics. May increase concentration of bromocriptine. Potentially Fatal: Requirements of insulin may be reduced requiring careful blood-glucose monitoring. Reduction in ciclosporin bioavailability and efficacy.

Adverse Effects

Side effects of Octreotide : >10% Gallbladder problems (>60%): Decreased gallbladder contractility, gallstones, cholecystitis, cholestatic hepatitis, Dysglycemia (25%), Hypothyroidism (25%), Bradycardia (25%) 1-10% ECG changes (10%), Arrhythmia (9%), Pancreatitis, Upper respiratory tract infection, Fatigue, Headache, Malaise, Rash, Diarrhea, Nausea, Vomiting, Pain at injection site, Joint pain, Blurred vision

Mechanism of Action

Octreotide is a synthetic analogue of somatostatin which acts by suppressing basal and stimulated secretion of growth hormone (GH). It also suppresses LH response to gonadotrophin-releasing hormone and reduces the secretion of gastrin, vasoactive intestinal peptide (VIP), insulin, glucagon, secretin, motilin and pancreatic polypeptide.