Sources & References

The blood concentration curves on the ADHD Graphs website were created from published data, collected from clinical studies, national governing bodies or validated pharmacokinetic models where key parameters like absorption rate, distribution volume, metabolism, and elimination half-life have been incorporated. Each curve represents the predicted concentration of a drug in the bloodstream over time, following a specific dosing schedule.

The amphetamine curves have been adjusted to reflect real world clinical response but can also be displayed as accurate concentration curves. The Y Axis scale is "relative likely concentration" or "clinical benefit". As an educational tool the clinician is expected to use whatever language works best for them.

To show both methylphenidate (MPH) and dexamphetamine (DEX) on the same scale a bioequivalence of MPH:DEX of 10mg:5mg was used. This has been based on published expert opinion. While these curves are indicative of likely blood concentrations when converting between methylphenidate and dexamphetamine products, clinical skill must be applied, as individual patient responses can vary, and adjustments may be necessary in clinical practice.

References by Medication

Dexamfetamine

  • Study Sandersleben HU, Mayer A, Ruhmann M, Dangel O, Schütz H. Pharmacokinetics of a Modified-Release Dexamphetamine Sulfate Formulation Following Single and Multiple Dosing in Healthy Adults: Comparative Bioavailability with Immediate-Release Dexamphetamine Sulfate, between Strengths, Assessment of Food and Meal Composition Effects. Scand J Child Adolesc Psychiatr Psychol. 2023 Nov 30;11(1):132-142. doi: 10.2478/sjcapp-2023-0014. PMID: 38033826; PMCID: PMC10687392.
  • URL DrugBank — Dextroamphetamine: https://go.drugbank.com/drugs/DB01576
  • URL FDA — Dexamphetamine prescribing information: https://www.accessdata.fda.gov/drugsatfda_docs/label/2007/017078s042lbl.pdf

Lisdexamfetamine (Vyvanse)

  • Study Kämmerer, W. (2024). Comparative pharmacology and abuse potential of oral dexamphetamine and lisdexamfetamine — A literature review. Human Psychopharmacology: Clinical and Experimental, 39(6), e2910. https://doi.org/10.1002/hup.2910
  • Study Dolder PC, Strajhar P, Vizeli P, Hammann F, Odermatt A, Liechti ME. Pharmacokinetics and Pharmacodynamics of Lisdexamfetamine Compared with D-Amphetamine in Healthy Subjects. Front Pharmacol. 2017 Sep 7;8:617. doi: 10.3389/fphar.2017.00617. PMID: 28936175; PMCID: PMC5594082.
  • Study Childress A, Findling R, Wu J, Kollins S, Wang Y, Martin P, Robertson B. (2020). Lisdexamfetamine Dimesylate for Preschool Children with Attention-Deficit/Hyperactivity Disorder. Journal of Child and Adolescent Psychopharmacology. 30. doi: 10.1089/cap.2019.0117.
  • Study Ermer JC, Pennick M, Frick G. Lisdexamfetamine Dimesylate: Prodrug Delivery, Amphetamine Exposure and Duration of Efficacy. Clin Drug Investig. 2016 May;36(5):341-56. doi: 10.1007/s40261-015-0354-y. PMID: 27021968; PMCID: PMC4823324.
  • Study Boellner SW, Stark JG, Krishnan S, Zhang Y. Pharmacokinetics of lisdexamfetamine dimesylate and its active metabolite, d-amphetamine, with increasing oral doses of lisdexamfetamine dimesylate in children with attention-deficit/hyperactivity disorder: a single-dose, randomized, open-label, crossover study. Clin Ther. 2010 Feb;32(2):252-64. doi: 10.1016/j.clinthera.2010.02.011. PMID: 20206783.
  • Study Ermer J, Homolka R, Martin P, Buckwalter M, Purkayastha J, Roesch B. Lisdexamfetamine dimesylate: linear dose-proportionality, low intersubject and intrasubject variability, and safety in an open-label single-dose pharmacokinetic study in healthy adult volunteers. J Clin Pharmacol. 2010 Sep;50(9):1001-10. doi: 10.1177/0091270009357346. PMID: 20173084.
  • Study Findling RL, Childress AC, Cutler AJ, Gasior M, Hamdani M, Ferreira-Cornwell MC, Squires L. Efficacy and safety of lisdexamfetamine dimesylate in adolescents with attention-deficit/hyperactivity disorder. J Am Acad Child Adolesc Psychiatry. 2011 Apr;50(4):395-405. doi: 10.1016/j.jaac.2011.01.007. PMID: 21421179.
  • Study Findling RL, Ginsberg LD, Jain R, Gao J. Effectiveness, safety, and tolerability of lisdexamfetamine dimesylate in children with attention-deficit/hyperactivity disorder: an open-label, dose-optimization study. J Child Adolesc Psychopharmacol. 2009 Dec;19(6):649-62. doi: 10.1089/cap.2008.0165. PMID: 20035583.
  • Study Krishnan S, Zhang Y. Relative bioavailability of lisdexamfetamine 70-mg capsules in fasted and fed healthy adult volunteers and in solution: a single-dose, crossover pharmacokinetic study. J Clin Pharmacol. 2008 Mar;48(3):293-302. doi: 10.1177/0091270007310381. PMID: 18285619.
  • URL DrugBank — Lisdexamfetamine: https://go.drugbank.com/drugs/DB01255
  • URL FDA — Lisdexamfetamine prescribing information (2007): https://www.accessdata.fda.gov/drugsatfda_docs/label/2007/021977lbl.pdf
  • URL FDA — Lisdexamfetamine prescribing information (2017): https://www.accessdata.fda.gov/drugsatfda_docs/label/2017/208510lbl.pdf
  • URL FDA — Multidiscipline review (2025): https://www.accessdata.fda.gov/drugsatfda_docs/nda/2025/219847Orig1s000MultidisciplineR.pdf
  • URL FDA — Clinical pharmacology: https://www.fda.gov/media/103258/download
  • URL TGA — Australian product information: https://www.tga.gov.au/sites/default/files/auspar-lisdexamfetamine-dimesilate-131023-pi.pdf
  • URL Health Canada — Product monograph: https://pdf.hres.ca/dpd_pm/00070353.PDF

Methylphenidate (General)

  • Study Stevens T, Sangkuhl K, Brown JT, Altman RB, Klein TE. PharmGKB summary: methylphenidate pathway, pharmacokinetics/pharmacodynamics. Pharmacogenet Genomics. 2019 Aug;29(6):136-154. doi: 10.1097/FPC.0000000000000376. PMID: 30950912; PMCID: PMC6581573.
  • Study Challman T, Lipsky J. Methylphenidate: Its Pharmacology and Uses. Mayo Clinic Proceedings, 75, 711-721.
  • Study Markowitz J, Straughn A, Patrick K. (2003). Advances in the Pharmacotherapy of Attention-Deficit–Hyperactivity Disorder: Focus on Methylphenidate Formulations. Pharmacotherapy. 23. 1281-99. doi: 10.1592/phco.23.12.1281.32697.
  • Study Swanson JM, Volkow ND. Serum and brain concentrations of methylphenidate: implications for use and abuse. Neuroscience & Biobehavioral Reviews, Volume 27, Issue 7, 2003, Pages 615-621. ISSN 0149-7634. https://www.sciencedirect.com/science/article/abs/pii/S0149763403001076
  • Study Patrick KS, Straughn AB, Minhinnett RR, Yeatts SD, Herrin AE, DeVane CL, Malcolm R, Janis GC, Markowitz JS. Influence of Ethanol and Gender on Methylphenidate Pharmacokinetics and Pharmacodynamics. Summarized by Charles Li, MD.
  • Study Jackson AJ. A Semi-physiologically Based Model for Methylphenidate Pharmacokinetics in Adult Humans. College of Pharmacy, Howard University. Published: 24-May-2019. DOI: 10.35248/0975-0851.19.11.390.
  • Study Spencer TJ et al. PET study examining pharmacokinetics, detection and likeability, and dopamine transporter receptor occupancy of short- and long-acting oral methylphenidate. The American Journal of Psychiatry 163(3) (2006): 387-95.
  • URL DrugBank — Methylphenidate: https://go.drugbank.com/drugs/DB00422

Methylphenidate LA (Ritalin LA)

  • Study Tuerck D, Wang Y, Maboudian M, Wang Y, Sedek G, Pommier F, Appel-Dingemanse S. Similar bioavailability of dexmethylphenidate extended (bimodal) release, dexmethylphenidate immediate release and racemic methylphenidate extended (bimodal) release formulations in man. Int J Clin Pharmacol Ther. 2007 Dec;45(12):662-8. doi: 10.5414/cpp45662. PMID: 18184535.
  • Study Markowitz J, Straughn A, Patrick K, Devane C, Pestreich L, Lee J, Wang Y, Muniz R. (2003). Pharmacokinetics of Methylphenidate After Oral Administration of Two Modified-Release Formulations in Healthy Adults. Clinical Pharmacokinetics. 42. 393-401. doi: 10.2165/00003088-200342040-00007.
  • Study Adjei A, Teuscher NS, Kupper RJ, Chang WW, Greenhill L, Newcorn JH, Connor DF, Wigal S. Single-dose pharmacokinetics of methylphenidate extended-release multiple layer beads administered as intact capsule or sprinkles versus methylphenidate immediate-release tablets (Ritalin®) in healthy adult volunteers. J Child Adolesc Psychopharmacol. 2014 Dec;24(10):570-578. doi: 10.1089/cap.2013.0135. PMID: 25514542; PMCID: PMC4268571.
  • URL FDA — Ritalin LA prescribing information: https://www.accessdata.fda.gov/drugsatfda_docs/label/2013/021284s020lbl.pdf

Methylphenidate XR (Concerta)

Intuniv (Guanfacine Extended Release)

General & Consumer Resources