Omeprazole
Mechanism of
Action:
- Omeprazole irreversibly
inhibits the H⁺/K⁺ ATPase (proton pump) present on the luminal surface
of gastric parietal cells.
- This blocks the final
step of gastric acid secretion, reducing both basal and stimulated
acid secretion.
- Since it binds covalently, new
proton pumps need to be synthesized for acid secretion to resume.
Pharmacokinetics:
- Route: Oral
- Form: Enteric-coated
capsules/tablets (acid-labile, destroyed by gastric acid)
- Absorption: In small intestine, bioavailability
~35-40% (increased on repeated dosing).
- Plasma half-life: 1–2 hours, but duration
of action lasts ~24 hours due to irreversible binding.
- Metabolism: Extensively in the liver
(CYP2C19, CYP3A4).
- Excretion: Urine and feces.
Therapeutic Uses:
Peptic ulcer disease (gastric and duodenal
ulcers)
Gastroesophageal reflux disease (GERD)
Zollinger-Ellison syndrome
(hypersecretory conditions)
Prevention and treatment of NSAID-induced
ulcers
Part of H. pylori eradication regimens
(triple therapy: Omeprazole + Clarithromycin + Amoxicillin/Metronidazole)
- Common:
- Headache
- Nausea, vomiting
- Diarrhea or constipation
- Abdominal pain
- Long-term use:
- Vitamin B₁₂ deficiency (↓ acid → ↓ B₁₂ release)
- Hypomagnesemia
- Increased risk of fractures (hip, spine, wrist)
- Increased risk of enteric
infections
(e.g., Clostridium difficile)
- Hypergastrinemia (rebound
acid hypersecretion on sudden withdrawal)
Drug Interactions:
- Omeprazole inhibits CYP2C19,
which can:
- Decrease activation of
Clopidogrel (↓ antiplatelet effect).
- Increase levels of Phenytoin,
Diazepam, Warfarin.
- Decreased absorption of
drugs requiring acidic pH:
- Ketoconazole, Itraconazole,
Iron, Vitamin B₁₂.
Contraindications:
- Known hypersensitivity
- Caution in severe hepatic
impairment.
Dose:
- 20–40 mg once daily, before
meals,
preferably in the morning.
END OF THE DOCUMENT
Hi. I’m Writer of Researchsop.com. ’ ’ Please share these SOPs to all concern pharma people for their development. I like to fullfill the need of curious people. These things inspire me to make things looks better.
0 comments:
Post a Comment