Octreotide
OCTREOTIDE
- Somatostatin analogue – Mimics natural somatostatin pharmacologically.
- More potent inhibitor of growth hormone, glucagon, & insulin than natural hormone.
MECHANISM OF ACTION:
- Due to inhibition of hormone secretion.
- Includes 5-HT, GI peptides like gastrin, vasoactive intestinal polypeptide (VIP), insulin & secretin.
PHARMACOKINETICS:
- Long acting: t½ ~90 min.
ACTION:
- Inhibits secretion of,
- Gastrin.
- CCK.
- VIP
- Glucagon.
- Growth hormone.
- Insulin.
- Secretin.
- Pancreatic polypeptide.
- TSH.
- Reduce secretion of intestinal & pancreatic fluids.
- Reduce GI motility.
- Inhibit gallbladder contraction.
- Cause vasoconstrictions.
- Reduces portal vessel pressure in bleeding varices.
INDICATION:
- Preferred over somatostatin for acromegaly.
- Suppress GH secretion from pituitary tumors.
In palliative gastrointestinal endocrine tumors management:
- In secretory diarrhoeas associated with.
- Carcinoid.
- Vasoactive intestinal polypeptide-secreting tumors.
- AIDS.
- Cancer chemotherapy.
- Diabetes.
- Diarrhoea control due to hormone suppression enhancing intestinal mucosal secretion.
- Decreases blood conc. of insulin-like growth factor-I (IGF-I) & somatomedin C.
In varices & gastroesophageal bleeding.
- Reduces postoperative complications of high-risk pancreatic surgery like,
- Abscess formation & sepsis.
- Acute pancreatitis.
- Pancreatic fistula.
- Peripancreatic fluid collection.
- Palliative symptomatic treatment of hyperinsulinemia.
- Due to severe refractory metastatic insulinoma.
ADVERSE EFFECT:
- Headache
- Hypothyroidism
- Cardiac conduction changes
- Gastrointestinal reactions
- Including cramps, nausea/vomiting and diarrhoea or constipation.
- Gallstones,
- Reduction of insulin release,
- Hyperglycemia/hypoglycemia.
- Slow heart rate,
- Skin reactions such as pruritus,
- Hyperbilirubinemia,
- Hypothyroidism,
- Dizziness
- Dyspnoea.
- Rare side effects include
- Acute anaphylactic reactions, pancreatitis and hepatitis
- A prolonged QT interval
Exam Question
- Drug of choice for diarrhea in AIDS is Octreotide
- Octreotide is used in Insulinoma, Glucagonoma & Carcinoids
- Octreotide is useful for Acromegaly, variceal bleeding,secretory diarrhea & Suppresses growth Hormone secretion.
- Octreotide can be used in the management of acute pancreatitis
Don’t Forget to Solve all the previous Year Question asked on Octreotide
