Dexmethylphenidate
Dexmethylphenidate, a stimulant. Pure d-threo methylphenidate — the pharmacologically active stereoisomer. Half the mg-dose of racemic… Oral half-life 3.7 h.
Pure d-threo methylphenidate — the pharmacologically active stereoisomer. Half the mg-dose of racemic methylphenidate for equivalent effect.
PK: F 0.23 is Srinivas 1993 (PMID:8430051), 11 healthy adults with an IV reference arm, verbatim "After oral administration of dl-MPH, the absolute bioavailability (F) of d-MPH was 0.23 and that of l-MPH was 0.05"; it transfers to enantiopure d-MPH on Patrick 2016 (PMID:26729760), a head-to-head IR crossover whose d-MPH AUC ratio fell inside 0.80-1.25. That is a two-paper chain, flagged as such: no study reports an absolute F for enantiopure d-MPH against IV. Half-life 2.5 h was replaced by 3.74 h (PMID:20861586, "For IR MPH, the half-life was 3.74 hours", 30 healthy adults) because nothing supports 2.5 h for d-MPH — that figure traces to PEDIATRIC RACEMIC sources. ka and V dropped: no human abstract reports either, the stored 100 L appears nowhere, and a ka of 1.5 /h would put tmax near 1.5 h against the 2.0-2.2 h consistently observed. NOTE the enantiomer relationship justifies sharing ELIMINATION parameters with methylphenidate but not absorption: enantiopure d-MPH reaches the circulation faster, its 1-hour concentration being 56% higher than after the racemate (PMID:26729760).
Pharmacokinetics
- Oral — t½ 3.7 h · F 23%
Sources: PMID:10628897, PMID:8430051, PMID:26729760, PMID:20861586