Octreotide

Parenteral
Acromegaly
Adult: In patients who are inadequately controlled by surgery or radiotherapy, unfit or unwilling to undergo surgery, or in interim period until radiotherapy becomes fully effective: As immediate release preparation: Initial: 50 mcg tid via SC inj, adjusted to the usual dose of 100-200 mcg tid according to individual GH and IGF-1 levels, symptoms and tolerability. Max: 500 mcg tid. Alternatively, doses may be given via IV in some countries. If there is no relevant reduction in GH levels and no improvement in symptoms within 3 months of starting treatment, discontinue therapy. Maintenance therapy with depot preparation may be started once control using SC inj is established. As extended-release depot preparation: Initial: 20 mg every 4 weeks via IM inj for 3 months. Adjust doses after 3 months to 10 mg or 30 mg every 4 weeks according to symptom control, and individual GH and IGF-1 levels. For patients who are not adequately controlled on 30 mg dosing, may increase dose to 40 mg every 4 weeks.
Renal impairment: Severe impairment requiring dialysis: Dose adjustment may be necessary.
Hepatic impairment: Cirrhosis: Dose adjustment may be necessary.
Reconstitution: IV infusion: Dilute with 50-200 mL of 0.9% NaCl solution or dextrose 5% in water. IM: Reconstitute with the provided diluent (refer to specific product guideline for detailed reconstitution instructions).
Incompatibility: Incompatible with TPN solutions due to the formation of glycosyl octreotide conjugates, which may reduce efficacy.

Subcutaneous
Prophylaxis of complications following pancreatic surgery
Adult: As immediate-release preparation: 100 mcg tid via SC inj. Doses are given for 7 consecutive days, starting on the day of operation at least 1 hour prior to laparotomy.
Hepatic impairment: Cirrhosis: Dose adjustment may be necessary.

Intravenous
Variceal haemorrhage in patients with cirrhosis
Adult: Used in association with specific therapy (e.g. endoscopic sclerotherapy): As immediate-release preparation: 25 mcg/hour via continuous IV infusion for 2 or up to 5 days. Doses of up to 50 mcg/hour have been used.
Hepatic impairment: Cirrhosis: Dose adjustment may be necessary.
Reconstitution: IV infusion: Dilute with 50-200 mL of 0.9% NaCl solution or dextrose 5% in water.
Incompatibility: Incompatible with TPN solutions due to the formation of glycosyl octreotide conjugates, which may reduce efficacy.

Parenteral
Diarrhoea associated with carcinoid tumour
Adult: As immediate-release preparation: Initially, 50 mcg once daily or bid via SC inj; gradually adjust doses to up to 600 mcg daily given in 2-4 divided doses according to individual response and tolerability. Higher doses may be needed for exceptional cases. In carcinoid tumours, if there is no beneficial response within 1 week of treatment, discontinue the therapy. If rapid response is required, initial doses may be given via IV infusion over 15-30 minutes. Maintenance therapy with a depot preparation may be started once symptom control using SC inj is established. As extended-release depot preparation: Initially, 20 mg every 4 weeks via deep IM inj; may be adjusted after 2 or 3 months to 10 mg or 30 mg every 4 weeks as necessary according to individual response. SC inj with an immediate-release preparation must be continued at the previously effective dose for 2 weeks after the 1st depot inj, and may be added to treatment if necessary thereafter.
Renal impairment: Severe impairment requiring dialysis: Dose adjustment may be necessary.
Hepatic impairment: Cirrhosis: Dose adjustment may be necessary.
Reconstitution: IV infusion: Dilute with 50-200 mL of 0.9% NaCl solution or dextrose 5% in water. IM: Reconstitute with the provided diluent (refer to specific product guideline for detailed reconstitution instructions).
Incompatibility: Incompatible with TPN solutions due to the formation of glycosyl octreotide conjugates, which may reduce efficacy.

Parenteral
Flushing associated with carcinoid tumour
Adult: As immediate-release preparation: Initially, 50 mcg once daily or bid via SC inj; gradually adjust doses to up to 600 mcg daily given in 2-4 divided doses according to individual response and tolerability. Higher doses may be needed for exceptional cases. In carcinoid tumours, if there is no beneficial response within 1 week of treatment, discontinue the therapy. If rapid response is required, initial doses may be given via IV infusion over 15-30 minutes. Maintenance therapy with a depot preparation may be started once symptom control using SC inj is established. As extended-release depot preparation: Initially, 20 mg every 4 weeks via deep IM inj; may be adjusted after 2 or 3 months to 10 mg or 30 mg every 4 weeks as necessary according to individual response. SC inj with an immediate-release preparation must be continued at the previously effective dose for 2 weeks after the 1st depot inj, and may be added to treatment if necessary thereafter.
Renal impairment: Severe impairment requiring dialysis: Dose adjustment may be necessary.
Hepatic impairment: Cirrhosis: Dose adjustment may be necessary.
Reconstitution: IV infusion: Dilute with 50-200 mL of 0.9% NaCl solution or dextrose 5% in water. IM: Reconstitute with the provided diluent (refer to specific product guideline for detailed reconstitution instructions).
Incompatibility: Incompatible with TPN solutions due to the formation of glycosyl octreotide conjugates, which may reduce efficacy.

Parenteral
Severe secretory diarrhoea associated with vasoactive intestinal peptide-secreting tumour
Adult: As immediate-release preparation: Initially, 50 mcg once daily or bid via SC inj; gradually adjust doses to up to 600 mcg daily given in 2-4 divided doses according to individual response and tolerability. Higher doses may be needed for exceptional cases. In carcinoid tumours, if there is no beneficial response within 1 week of treatment, discontinue the therapy. If rapid response is required, initial doses may be given via IV infusion over 15-30 minutes. Maintenance therapy with a depot preparation may be started once symptom control using SC inj is established. As extended-release depot preparation: Initially, 20 mg every 4 weeks via deep IM inj; may be adjusted after 2 or 3 months to 10 mg or 30 mg every 4 weeks as necessary according to individual response. SC inj with an immediate-release preparation must be continued at the previously effective dose for 2 weeks after the 1st depot inj, and may be added to treatment if necessary thereafter.
Renal impairment: Severe impairment requiring dialysis: Dose adjustment may be necessary.
Hepatic impairment: Cirrhosis: Dose adjustment may be necessary.
Reconstitution: IV infusion: Dilute with 50-200 mL of 0.9% NaCl solution or dextrose 5% in water. IM: Reconstitute with the provided diluent (refer to specific product guideline for detailed reconstitution instructions).
Incompatibility: Incompatible with TPN solutions due to the formation of glycosyl octreotide conjugates, which may reduce efficacy.

Parenteral
Necrolytic migratory erythema associated with glucagonoma
Adult: As immediate-release preparation: Initially, 50 mcg once daily or bid via SC inj; gradually adjust doses to up to 600 mcg daily given in 2-4 divided doses according to individual response and tolerability. Higher doses may be needed for exceptional cases. In carcinoid tumours, if there is no beneficial response within 1 week of treatment, discontinue the therapy. If rapid response is required, initial doses may be given via IV infusion over 15-30 minutes. Maintenance therapy with a depot preparation may be started once symptom control using SC inj is established. As extended-release depot preparation: Initially, 20 mg every 4 weeks via deep IM inj; may be adjusted after 2 or 3 months to 10 mg or 30 mg every 4 weeks as necessary according to individual response. SC inj with an immediate-release preparation must be continued at the previously effective dose for 2 weeks after the 1st depot inj, and may be added to treatment if necessary thereafter.
Renal impairment: Severe impairment requiring dialysis: Dose adjustment may be necessary.
Hepatic impairment: Cirrhosis: Dose adjustment may be necessary.
Reconstitution: IV infusion: Dilute with 50-200 mL of 0.9% NaCl solution or dextrose 5% in water. IM: Reconstitute with the provided diluent (refer to specific product guideline for detailed reconstitution instructions).
Incompatibility: Incompatible with TPN solutions due to the formation of glycosyl octreotide conjugates, which may reduce efficacy.

Patient with insulinomas, diabetes mellitus; heart failure, conditions which cause excessive fluid loss; history of vitamin B₁₂ deprivation; liver cirrhosis. Renal and hepatic impairment. Pregnancy and lactation. Monitoring Parameters Monitor hepatic function; serum GH and IGF-1 (in acromegaly); urinary 5-hydroxyindole acetic acid (5-HIAA), plasma serotonin and plasma substance P (in carcinoid tumours); plasma VIP (in VIPomas). Assess for signs of tumour expansion (e.g. visual field defects). Chronic treatment: Monitor thyroid function (e.g. TSH, total and/or free T₄) at baseline and periodically; cardiac function (e.g. ECG, heart rate), vitamin B₁₂ levels; blood glucose and glycaemic control (in diabetic patients); zinc level (in patients with excessive fluid loss maintained on TPN). Perform gallbladder monitoring and ultrasound examination as necessary.

Significant: Bradycardia, conduction abnormalities, arrhythmia; impaired gallbladder function causing cholelithiasis and its related complications (e.g. cholecystitis, cholangitis, pancreatitis); hypoglycaemia, hyperglycaemia, hypothyroidism. Blood and lymphatic system disorders: Hyperbilirubinaemia. Gastrointestinal disorders: Nausea, vomiting, diarrhoea, abdominal pain, abdominal bloating, constipation, flatulence, dyspepsia, loose stools, steatorrhoea, discolourations of faeces. General disorders and administration site conditions: Injection site pain, asthenia. Investigations: Elevated transaminases; decreased TSH, total and free T₄. Metabolism and nutrition disorders: Anorexia, impaired glucose tolerance. Nervous system disorders: Headache, dizziness. Respiratory, thoracic and mediastinal disorders: Dyspnoea. Skin and subcutaneous tissue disorders: Pruritus, rash, alopecia.

Symptoms: Weakness, lethargy, diarrhoea, weight loss, hot flushes, hypotension, arrhythmia, pancreatitis, hepatic steatosis, hepatomegaly, lactic acidosis, brain hypoxia, and cardiac arrest. Management: Symptomatic treatment.

May impair insulin secretion; dosage adjustments of insulins and other antidiabetic medications may be required. Decreased intestinal absorption of ciclosporin. Delayed intestinal absorption of cimetidine. Increased bioavailability of bromocriptine. May cause additive bradycardia; dose adjustment of β-blockers, Ca channel blockers, or drugs that control fluid and electrolyte balance may be necessary.

Absorption of dietary fats may be altered by octreotide.

May cause an abnormal Schilling's test (chronic treatment).

Octreotide, a synthetic octapeptide analogue of somatostatin, prevents the release of serotonin, gastrin, vasoactive intestinal polypeptide (VIP), glucagon, insulin, motilin, secretin, and pancreatic polypeptide to control gastrointestinal and other symptoms associated with various conditions. It reduces the concentration of growth hormone (GH) and insulin-like growth factor 1 (IGF-1) in acromegaly. It also suppresses the LH response to gonadotropin-releasing hormone (GnRH), secretion of TSH, and reduces the splanchnic blood flow.
Duration: 6-12 hours (SC).
Absorption: Rapidly and completely absorbed after SC administration; slowly released via microsphere degradation in the muscle (IM). Bioavailability: 100% (SC); 60-63% of SC dose (IM). Time to peak plasma concentration: Approx 0.4-0.7 hours (SC); 1 hour (IM).
Distribution: Crosses the placenta and enters breast milk. Volume of distribution: 14 L. Plasma protein binding: Approx 40-65%.
Metabolism: Extensively metabolised in the liver.
Excretion: Via urine (32% as unchanged drug). Elimination half-life: 1.7-1.9 hours.

Intravenous: Store between 2-8°C. Protect from light. Do not freeze. Reconstituted solutions for IV infusion are stable below 25°C for 24 hours. Parenteral: Store between 2-8°C. Protect from light. Do not freeze. Reconstituted solutions for IV infusion are stable below 25°C for 24 hours. Prefilled pens may be stored between 20-25°C for 28 days after first use. Subcutaneous: Store between 2-8°C. Protect from light. Do not freeze. Prefilled pens may be stored between 20-25°C for 28 days after first use.

Other Gastrointestinal Drugs / Trophic Hormones & Related Synthetic Drugs

H01CB02 - octreotide ; Belongs to the class of antigrowth hormone. Used in hypothalamic hormone preparations.