Clinical data
ATC code
  • none
CAS Number
PubChem CID
Chemical and physical data
Molar mass247.38 g/mol g·mol−1
3D model (JSmol)

Picenadol (LY-97435) is a 4-phenylpiperidine derivative that is an opioid analgesic drug developed by Eli Lilly in the 1970s.[1]

Picenadol is an effective analgesic with similar efficacy to pethidine (meperidine). It has been investigated for some applications such as obstetrics[2] and dentistry,[3] but never commercialised.

It is unusual in that one enantiomer is a pure μ-opioid agonist, while the other is an antagonist.[4] The (3R,4R) isomer is the agonist, while (3S,4S) is antagonist.[5] This means that the racemic mix of the two enantiomers is a mixed agonist-antagonist, with relatively low abuse potential, and little of the κ-opioid activity that tends to cause problems with other opioid mixed agonist-antagonists such as pentazocine.[6]


Picenadol synthesis 1: U.S. Patent 4,499,274
Picenadol synthesis 2:[7]

See also[edit]


  1. ^ US Patent 4081450 - 1,3,4-Trisubstituted-4-arylpiperidines and their preparation
  2. ^ Sherline DM. Picenadol (LY 150720) compared with meperidine and placebo for relief of post-cesarean section pain: a randomized double-blind study. American Journal of Obstetrics and Gynecology. 1983 Oct 15;147(4):404-6.
  3. ^ Goldstein DJ, Brunelle RL, George RE, Cooper SA, Desjardins PJ, Gaston GW, Jeffers GE, Gallegos LT, Reynolds DC. Picenadol in a large multicenter dental pain study. Pharmacotherapy. 1994 Jan-Feb;14(1):54-9.
  4. ^ Leander JD, Zimmerman DM. Effects of picenadol and its agonist and antagonist isomers on schedule-controlled behavior. Journal of Pharmacology and Experimental Therapeutics. 1983 Dec;227(3):671-5.
  5. ^ Froimowitz M, Cody V. Absolute configurations and conformations of the opioid agonist and antagonist enantiomers of picenadol. Chirality. 1995;7(7):518-25.
  6. ^ Zimmerman DM, Smits SE, Hynes MD, Cantrell BE, Leander JD, Mendelsohn LG, Nickander R. Picenadol. Drug and Alcohol Dependence. 1985 Feb;14(3-4):381-401.
  7. ^ Martinelli, M. J.; Peterson, B. C. (1990). "A concise, stereoselective synthesis of picenadol". Tetrahedron Letters. 31 (38): 5401. doi:10.1016/S0040-4039(00)97857-2.