Pethidine
Also called meperidine.
An older opioid painkiller, known as meperidine in the United States and sold as Demerol. Pethidine (C15H21NO2, 247 g/mol) is an opioid dispensed on prescription.
Sources and notes
- The introductionfrom sourceMoleculeFinder curated
- Other namesfrom sourceWikidataIts English label and aliases on Wikidata.
- Formula and weightcomputedPubChem
- 2D drawingcomputedPubChem structure, drawn by RDKit
- 3D modelfrom sourcePubChem 3D conformerLoaded after the page has painted, and on a phone only when you ask for it; the 2D drawing shows until it arrives.
Where you encounter it
Dispensed on prescription, not sold on a shelf. Pethidine on the product labels we hold.
Medicines
Every product and list we hold
Sources and notes
- The product labels and their strengthsfrom sourceDailyMed (FDA label)Each label lists the molecule as an ingredient, and an active ingredient at the strength shown.
- How it gets therefrom sourceMoleculeFinder curatedEach mark is set by hand on our lists, never inferred; a label's ingredient is added by the maker. A row with no mark data says Not marked.
- The line abovefrom sourceMoleculeFinder curatedFrom the group the molecule belongs to.
Explore its structure
Choose a part to light it up.
A C=O joined through an oxygen to another carbon, the link an acid and an alcohol make when they combine. Water can split it back into the two.
From: standard chemistry.
A nitrogen bonded to three carbons, with no hydrogen of its own. Its spare pair of electrons can still pick up a hydrogen ion, so a tertiary amine is a base.
From: standard chemistry.
Six carbons in a flat hexagon, sharing their electrons evenly around the ring. It is stable, flat and oily, and it stacks readily against other flat rings.
From: standard chemistry.
Sources and notes
- The drawingcomputedPubChem structure, drawn by RDKitThe page's one shipped drawing, with the chosen part lit in amber under it.
- The partscomputedFound by ruleEach part is found by a chemical pattern, never picked by hand atom by atom; its words say where they come from.
Properties and sources
Calculated by PubChem
- Molecular formula
- C15H21NO2
- Molecular weight
- 247.33 g/mol
- XLogP3octanol/water, log units
- 2.5
- Polar surface areatopological
- 29.5 Ų
- H-bond donors
- 0
- H-bond acceptors
- 3
- Rotatable bonds
- 4
- Complexity
- 276
Measured LD50, HSDB via PubChem
162 mg/kg pure pethidine, rat, oral
An LD50 is an animal study measurement, not a dose for a person.
Reported Hazard label (GHS), ECHA, HSDB via PubChem
Danger Toxic pictogram (GHS06), Irritant pictogram (GHS07) and Health hazard pictogram (GHS08); hazard statements H301, H317, H331, H334
Reported Licence
The US Food and Drug Administration licenses Pethidine for human use (NDA 021171, authorized November 10, 1942), as Demerol. Drugs@FDA
Groups it belongs to
- Category
- Prescription medicine
- Family
- Opioids
- Elements
- Nitrogen
- Hazard classes
- Acutely toxic, Irritant, Health hazard, GHS Danger
CCOC(=O)C1(CCN(CC1)C)C2=CC=CC=C2PubChem CID 4058 · Wikidata Q55434 · InChIKey XADCESSVHJOZHK-UHFFFAOYSA-N · Data refreshed
Questions
- What is Pethidine?
- An older opioid painkiller, known as meperidine in the United States and sold as Demerol. Pethidine (C15H21NO2, 247 g/mol) is an opioid dispensed on prescription.
- How toxic is Pethidine?
- The reported LD50 of Pethidine is 162 mg/kg (rat, oral). An LD50 is an animal study measurement, not a dose for a person. Its GHS hazard label carries the signal word Danger and the hazard pictograms Toxic, Irritant and Health hazard. from sourcefrom source
- What kind of molecule is Pethidine?
- Pethidine has the formula C15H21NO2 and a molecular weight of 247.33 g/mol. MoleculeFinder files it under opioids, in the prescription medicine group. from sourcefrom sourcefrom sourcefrom source
- What else is Pethidine called?
- Pethidine is also called meperidine. from source
- Who licenses Pethidine as a medicine?
- The US Food and Drug Administration licenses Pethidine for human use (NDA 021171, authorized November 10, 1942), as Demerol. from source
Sources and notes
- Calculated valuescomputedPubChemComputed from the structure, so no laboratory conditions apply; complexity is PubChem's own structural score.
- LD50from sourceHSDB via PubChemOther values the sources report: rat, oral, 170 mg/kg; rat, another route, 87 mg/kg; rat, another route, 113 mg/kg. The page shows the one LD50 the site uses everywhere.
- Hazard labelfrom sourceECHA, HSDB via PubChemThe label combines these classifications.
- ECHAfrom sourceAttributionSource: European Chemicals Agency, echa.europa.eu.
- Licencefrom sourceDrugs@FDARead 2026-10-21.
- Data refreshedfrom sourceMoleculeFinder2026-11-09