Lisdexamfetamine vs Dextroamphetamine: what is the difference?
Lisdexamfetamine is dextroamphetamine with the amino acid lysine attached, and it does nothing until the blood cuts the lysine off.
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. Aligned; 9 atoms differ, too many to mark as one group.
- Structural similaritycomputedRDKit Morgan/Tanimoto0.40 of 1, a Morgan fingerprint Tanimoto coefficient. It measures shape, not effect.
Side by side
| Lisdexamfetamine | Dextroamphetamine | |
|---|---|---|
| Molecular weightCalculated PubChem | 263.38 g/molC15H25N3O | 135.21 g/molC9H13N |
| Hydrogen-bond donorsCalculated PubChem | 3 | 1 |
| FamilyEditorial MoleculeFinder curated | Stimulants | Stimulants |
| Everyday groupEditorial MoleculeFinder curated | Prescription medicine | Prescription medicine |
| Chemical groupsCalculated Found by rule (RDKit) | Amines, Aromatics, Amides | Amines, Aromatics |
| Hazard labelReported HSDB via PubChem; ECHA, HSDB via PubChem | Danger | Danger |
| The supplier-filed hazard label's signal word, not a statement about ordinary use. | ||
| Oral LD50Measured HSDB via PubChem | Not recorded | 38 mg/kgpure dextroamphetamine, 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.
- 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 sourceHSDB via PubChem; ECHA, HSDB via PubChem
- Oral LD50from sourceHSDB via PubChem
- ECHAfrom sourceAttributionSource: European Chemicals Agency, echa.europa.eu.
- Identifiersfrom sourcePubChemPubChem CID 11597698 (Lisdexamfetamine) and 5826 (Dextroamphetamine).
In more detail
Enzymes in the blood do that cutting. That conversion is the entire design: it happens at a rate the body sets rather than one a formulation sets, which gives a smoother rise and makes the molecule far less useful if crushed or injected. Once cleaved, what circulates is dextroamphetamine, so the two are the same drug arriving by different routes. Lisdexamfetamine is the much heavier molecule at 263.38 against 135.21 because of the attached lysine, and only part of that weight is the active portion. Both are controlled substances in the US.
Sources and notes
- The paragraphfrom sourceMoleculeFinder comparison notes
Questions
- What is the difference between Lisdexamfetamine and Dextroamphetamine?
- Lisdexamfetamine is dextroamphetamine with the amino acid lysine attached, and it does nothing until the blood cuts the lysine off.
- Is Lisdexamfetamine bigger than Dextroamphetamine?
- Lisdexamfetamine is the heavier molecule, 263.38 g/mol against 135.21 g/mol for Dextroamphetamine. Lisdexamfetamine is C15H25N3O and Dextroamphetamine is C9H13N.
Sources and notes
- The answersfrom sourceMoleculeFinderThe first is the pair's answer line; the others are read off the table above.