Systematic (IUPAC) name
Clinical data
Trade names Dividol
Legal status
  • OTC
Routes of
CAS Registry Number  YesY
ATC code N02
PubChem CID:
ChemSpider  N
Synonyms Viminol, Dividol
Chemical data
Formula C21H31ClN2O
Molecular mass 362.94 g/mol

Viminol (marketed under the brandname Dividol) is an opioid analgesic developed by a team at the drugs company Zambon in the 1960s.[1] Viminol is based on the α-Pyrryl-2-Amino-Ethanol structure unlike any other class of opioids;[2][3]

Viminol has both antitussive (cough suppressing) and analgesic (pain reducing) effects. It has six different stereoisomers which have varying properties. 4 are inactive, the 1S-(R,R)-disecbutyl isomer being a μ-opioid full agonist around 5.5 times more potent than morphine while the 1S-(S,S)-disecbutyl isomer is an antagonist.[4][5] Since vimonol is supplied as a racemic mixture of isomers, the overall effect produces a mixed agonist–antagonist profile similar to that of opioids such as pentazocine, although with somewhat fewer side effects.[6]

Later work[7] showed that replacing the -Cl moiety with an -F or a -CF3 produced a compound with twice the potency and half the acute toxicity. A later team at Zambon modified the pyrrolidine with a pyrrolidone[8] could produce an analogue some 318x morphine in its analgesic activity in animal studies (the latter overlays beta hydroxy fentanyl). A number of related compounds were found to be active allowing a QSAR to be constructed.

Viminol has similar effects to other opioids, and produces analgesia, sedation and euphoria.

Side Effects

Side effects are similar to other opioids, and can include:

However, since viminol is supplied as a racemic mixture of agonist and antagonist isomers, the abuse potential and respiratory depression tends to be less than that of μ-opioid full agonist drugs.


  1. ^ US patent 3539589, Uberto M Teotino and Davide Della Bella, "1-(α-PYRRYL)-2-AMINO ETHANOLS", published 1967-05-08, issued 1970-10-11 
  2. ^ Contri AM. Chromatographic separation of diastereoisomers of aminoalcohol salts and their densitometric determination. (Italian). Il Farmaco. 1981 Apr;36(4):215-22.
  3. ^ Neto JM, Murad JE, Monteiro SS. Psychopharmacological properties of the viminol-p-hydroxybenzoate. Revista Brasileira de Pesquisas Medicas e Biologicas. 1977 Dec;10(6):361-8.
  4. ^ US Patent 3857857 - Davide Della Bella, Carlo Veneziani Bresso, Dario Chiarnio Monza & Uberio Maria Tiotino 'Stereoisomers of 1(1'(-O-Chlorobenzyl)-2'-Pyrryl)-2-Disec.Butylamino-Ethanol'
  5. ^ Shook JE, Kallman MJ, Dewey WL. The discriminative stimulus properties of the R2 isomer of viminol. Pharmacology, Biochemistry and Behaviour. 1984 Jan;20(1):59-62.
  6. ^ Cinelli M, Costa V, Ventresca GP, Lodola E. Viminol R2 analgesic activity in patients with postoperative pain: comparison with pentazocine. International Journal of Clinical Pharmacology, Therapy and Toxicology. 1986 May;24(5):232-5.
  7. ^ US Patent 4148907
  8. ^ US Patent 4960788