Clinical data
Trade names EPH
Routes of
Insufflation, vaporized, intravenous, intramuscular, rectal, oral, sublingual
ATC code none
Legal status
Legal status
Pharmacokinetic data
Bioavailability Variable
Protein binding Unknown
Metabolism Hepatic transesterification of prodrugs methylphenidate and ethanol
Biological half-life Less than 4hrs[note 1]
Excretion Urine
CAS Number 57413-43-1 YesY
PubChem (CID) 3080846
ChemSpider 2338571 YesY
Chemical and physical data
Formula C15H21NO2
Molar mass 247.33274 g/mol
3D model (Jmol) Interactive image
 NYesY (what is this?)  (verify)

Ethylphenidate (EPH) is a psychostimulant and a close analog of methylphenidate.

Ethylphenidate acts as both a dopamine reuptake inhibitor and norepinephrine reuptake inhibitor, meaning it effectively boosts the levels of the norepinephrine and dopamine neurotransmitters in the brain, by binding to, and partially blocking the transporter proteins that normally remove those monoamines from the synaptic cleft.

There have been anecdotal reports of a perforated septum resulting from even just a few uses of ethylphenidate by insufflation (snorting). This is almost certainly due to ethylphenidate being caustic or containing caustic impurities, as users report that insufflation is extremely painful.


Ethylphenidate metabolizes into methylphenidate and ritalinic acid.[1]

Tiny amounts of ethylphenidate can be formed in vivo when ethanol and methylphenidate are coingested, via hepatic transesterification.[2] Ethylphenidate formation appears to be more common when large quantities of methylphenidate and alcohol are consumed at the same time, such as in non-medical use or overdose scenarios.[3] However, the transesterfication process of methylphenidate to ethylphenidate, as tested in mice liver, was dominant in the inactive (−)-enantiomer but showed a prolonged and increased maximal plasma concentration of the active (+)-enantiomer of methylphenidate.[4] Additionally, only a few percent of the consumed methylphenidate is converted to ethylphenidate.[2]

This carboxylesterase-dependent transesterification process is also known to occur when cocaine and alcohol are consumed together, forming cocaethylene.[5]


All available data on ethylphenidate's pharmacokinetics are drawn from studies conducted on rodents. Ethylphenidate is more selective to the dopamine transporter (DAT) than methylphenidate, having approximately the same efficacy as the parent compound,[4] but has significantly less activity on the norepinephrine transporter (NET).[6] Its dopaminergic pharmacodynamic profile is nearly identical to methylphenidate, and is primarily responsible for its euphoric and reinforcing effects.[7]

The eudysmic ratio for ethylphenidate is superior to that of methylphenidate.[4]

The following is ethylphenidate's binding profile in the mouse, alongside methylphenidate's. Figures for both the racemic and the dextrorotary enantiomers are given:[6]

Compound Binding DAT Binding NET Uptake DA Uptake NE



  1. Shorter lasting than methylphenidate according to subjective reports

See also


  1. Noelia Negreira; Claudio Erratico; Alexander L.N. van Nuijs; Adrian Covaci (January 2016). "Identification of in vitro metabolites of ethylphenidate by liquid chromatography coupled to quadrupole time-of-flight mass spectrometry". Journal of Pharmaceutical and Biomedical Analysis. 117 (5): 474–484. doi:10.1016/j.jpba.2015.09.029. PMID 26454340.
  2. 1 2 Markowitz, J. S.; Devane, C. L.; Boulton, D. W.; Nahas, Z.; Risch, S. C.; Diamond, F.; Patrick, K. S. (2000). "Ethylphenidate formation in human subjects after the administration of a single dose of methylphenidate and ethanol". Drug metabolism and disposition: the biological fate of chemicals. 28 (6): 620–624. PMID 10820132.
  3. Markowitz, J. S.; Logan, B. K.; Diamond, F.; Patrick, K. S. (1999). "Detection of the novel metabolite ethylphenidate after methylphenidate overdose with alcohol coingestion". Journal of Clinical Psychopharmacology. 19 (4): 362–366. doi:10.1097/00004714-199908000-00013. PMID 10440465.
  4. 1 2 3 Patrick, K.; Williard, R.; Vanwert, A.; Dowd, J.; Oatis, J.; Middaugh, L. (2005). "Synthesis and pharmacology of ethylphenidate enantiomers: the human transesterification metabolite of methylphenidate and ethanol". Journal of Medicinal Chemistry. 48 (8): 2876–2881. doi:10.1021/jm0490989. PMID 15828826.
  5. Bourland, J.; Martin, D.; Mayersohn, M. (1997). "Carboxylesterase-mediated transesterification of meperidine (Demerol) and methylphenidate (Ritalin) in the presence of 2H6ethanol: preliminary in vitro findings using a rat liver preparation". Journal of pharmaceutical sciences. 86 (12): 1494–1496. doi:10.1021/js970072x. PMID 9423167.
  6. 1 2 Williard, R.; Middaugh, L.; Zhu, H.; Patrick, K. (2007). "Methylphenidate and its ethanol transesterification metabolite ethylphenidate: brain disposition, monoamine transporters and motor activity". Behavioural Pharmacology. 18 (1): 39–51. doi:10.1097/FBP.0b013e3280143226. PMID 17218796.
  7. Jatlow, P.; Elsworth, J. D.; Bradberry, C. W.; Winger, G.; Taylor, J. R.; Russell, R.; Roth, R. H. (1991). "Cocaethylene: a neuropharmacologically active metabolite associated with concurrent cocaine-ethanol ingestion". Life Sciences. 48 (18): 1787–1794. doi:10.1016/0024-3205(91)90217-Y. PMID 2020260.
  9. "Re: TCDOs and ACMD position on methylphenidate-based NPS" (PDF). 2016-02-29. Retrieved 2016-11-28.
  15. "关于印发《非药用类麻醉药品和精神药品列管办法》的通知" (in Chinese). China Food and Drug Administration. 27 September 2015. Retrieved 1 October 2015.

See also

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