Famotidine vs Omeprazole: what is the difference?
Famotidine turns down the histamine signal for acid and works within an hour, while omeprazole disables the acid pump itself and reduces acid more completely.
Sources and notes
- The sentence under the titlefrom sourceMoleculeFinder comparison notesThe pair's answer line.
- The two drawingscomputedMoleculeFinder rule (RDKit MCS)Each molecule's own drawing, as its page shows it. The common core, 3 of 24 atoms, is too small to align on.
Side by side
| Famotidine | Omeprazole | |
|---|---|---|
| Molecular weightCalculated PubChem | 337.5 g/molC8H15N7O2S3 | 345.4 g/molC17H19N3O3S |
| Hydrogen-bond donorsCalculated PubChem | 4 | 1 |
| Also sold asEditorial MoleculeFinder curated | Pepcid | Prilosec, Zegerid |
| FamilyEditorial MoleculeFinder curated | Over-the-counter medicines | Over-the-counter medicines |
| Everyday groupEditorial MoleculeFinder curated | OTC medicine | OTC medicine |
| Chemical groupsCalculated Found by rule (RDKit) | Amines | Aromatics, Ethers |
| Hazard labelReported ECHA via PubChem | Not recorded | Warning |
| The supplier-filed hazard label's signal word, not a statement about ordinary use. | ||
| Oral LD50Measured HSDB via PubChem | Not recorded | 4,000 mg/kgpure omeprazole, rat, oral |
| A single acute animal measure. It ranks nothing about human safety. | ||
Sources and notes
- Molecular weightcomputedPubChemComputed from the structure; the formula is under each weight.
- Hydrogen-bond donorscomputedPubChemThe hydrogens on nitrogen or oxygen that each molecule can lend to a hydrogen bond, counted from its structure.
- Also sold asfrom sourceMoleculeFinder curated
- Familyfrom sourceMoleculeFinder curated
- Everyday groupfrom sourceMoleculeFinder curated
- Chemical groupscomputedFound by rule (RDKit)Each group is found in the structure by a chemical pattern.
- Hazard labelfrom sourceECHA via PubChem
- Oral LD50from sourceHSDB via PubChem
- ECHAfrom sourceAttributionSource: European Chemicals Agency, echa.europa.eu.
- Identifiersfrom sourcePubChemPubChem CID 3325 (Famotidine) and 4594 (Omeprazole).
In more detail
Both reduce stomach acid and they act at different points in the same machinery. Famotidine is an H2 blocker: it blocks the histamine receptor on the acid-producing cell, which turns the signal down and works within an hour. Omeprazole is a proton pump inhibitor: it permanently disables the pump that actually moves acid into the stomach, so it takes days of repeated use to reach full effect but reduces acid far more completely. That is why one is useful for occasional heartburn and the other for sustained reduction. Omeprazole needs an acidic environment to activate, which is why its capsules are coated to survive until they are absorbed. Famotidine is the smaller molecule at 337.5 against 345.4 and contains sulfur in two places.
Sources and notes
- The paragraphfrom sourceMoleculeFinder comparison notes
Questions
- What is the difference between Famotidine and Omeprazole?
- Famotidine turns down the histamine signal for acid and works within an hour, while omeprazole disables the acid pump itself and reduces acid more completely.
- Is Famotidine bigger than Omeprazole?
- Omeprazole is the heavier molecule, 345.4 g/mol against 337.5 g/mol for Famotidine. Famotidine is C8H15N7O2S3 and Omeprazole is C17H19N3O3S.
Sources and notes
- The answersfrom sourceMoleculeFinderThe first is the pair's answer line; the others are read off the table above.