Diazepam vs Lorazepam: what is the difference?
Diazepam breaks down into several active metabolites that build up with repeated use, while lorazepam produces none, so its effect ends more cleanly.
Three differences: a methyl group on diazepam, and a hydroxyl group and a chlorine on lorazepam.
Sources and notes
- The sentence under the titlefrom sourceMoleculeFinder comparison notesThe pair's answer line.
- The two drawingscomputedMoleculeFinder rule (RDKit MCS)Drawn the same way round on the skeleton they share; the amber marks where the two differ.
- The captionfrom sourceMoleculeFinder curated
- What is highlightedfrom sourceMoleculeFinder curatedOne line under each drawing, written from the atoms the amber marks.
Side by side
| Diazepam | Lorazepam | |
|---|---|---|
| Molecular weightCalculated PubChem | 284.74 g/molC16H13ClN2O | 321.2 g/molC15H10Cl2N2O2 |
| Hydrogen-bond donorsCalculated PubChem | 0 | 2 |
| FamilyEditorial MoleculeFinder curated | Benzodiazepines | Benzodiazepines |
| Everyday groupEditorial MoleculeFinder curated | Prescription medicine | Prescription medicine |
| Chemical groupsCalculated Found by rule (RDKit) | Aromatics, Amides, Halogenated | Alcohols, Aromatics, Amides, Halogenated |
| Hazard labelReported ECHA via PubChem | Danger | Warning |
| The supplier-filed hazard label's signal word, not a statement about ordinary use. | ||
| Oral LD50Measured HSDB via PubChem | 710 mg/kgpure diazepam, rat, oral | Not recorded |
| 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.
- 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 3016 (Diazepam) and 3958 (Lorazepam).
In more detail
Both are benzodiazepines and the useful distinction is what the liver has to do with them. Diazepam is broken down through oxidation into several active metabolites, so its effect outlasts the parent molecule and accumulates with repeated use, especially in older people and in anyone with reduced liver function. Lorazepam is conjugated directly and produces no active metabolite, so its effect ends more cleanly, which is why it is often preferred where liver function is a concern. Diazepam is the more fat-soluble of the two and reaches the brain faster, which matters when either is used for an acute seizure. Lorazepam is the heavier at 321.2 against 284.7.
Sources and notes
- The paragraphfrom sourceMoleculeFinder comparison notes
Questions
- What is the difference between Diazepam and Lorazepam?
- Diazepam breaks down into several active metabolites that build up with repeated use, while lorazepam produces none, so its effect ends more cleanly.
- Is Diazepam bigger than Lorazepam?
- Lorazepam is the heavier molecule, 321.2 g/mol against 284.74 g/mol for Diazepam. Diazepam is C16H13ClN2O and Lorazepam is C15H10Cl2N2O2.
Sources and notes
- The answersfrom sourceMoleculeFinderThe first is the pair's answer line; the others are read off the table above.