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Pharmacokinetics and pharmacodynamics of (+)‐ threo ‐methylphenidate enantiomer in patients with hypersomnia
Author(s) -
Aoyama Takao,
Sasaki Tsukasa,
Kotaki Hajime,
Sawada Yasufumi,
Sudoh Yasuhiko,
Honda Yutaka,
Iga Tatsuji
Publication year - 1994
Publication title -
clinical pharmacology and therapeutics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.941
H-Index - 188
eISSN - 1532-6535
pISSN - 0009-9236
DOI - 10.1038/clpt.1994.27
Subject(s) - methylphenidate , pharmacokinetics , pharmacodynamics , pharmacology , enantiomer , medicine , chemistry , psychiatry , stereochemistry , attention deficit hyperactivity disorder
The pharmacokinetics of (+)‐methylphenidate after oral administration of 20 mg racemic methylphenidate hydrochloride and the relationship between clinical effects of plasma (+)‐methylphenidate concentration were investigated in 15 patients with hypersomnia and four healthy volunteers. The elimination half‐life of (+)‐methylphenidate in patients was within the range of 2.6 to 3 hours, and the time to reach the peak concentration ranged from 1 to 3 hours. The values of half‐life and time to reach the peak concentration in the patients were almost the same as the values in healthy subjects. The plasma (+)‐methylphenidate concentration profiles after repeated administration of racemic methylphenidate were similar to those after single administration. No correlation was observed between the plasma (+)‐methylphenidate concentration and the subjective sleepiness as measured by Stanford Sleepiness Scale. On the other hand, a significant correlation was found between the sleep latency as measured by the multiple sleep latency test and the plasma concentrations of (+)‐methylphenidate ( r = 0.850). The time course of the sleep latency after repeated administration was similar to that after single administration. The sleep latency of more than 10 minutes was achieved by maintaining the plasma (+)‐methylphenidate concentrations above 3 ng/ml. Clinical Pharmacology and Therapeutics (1994) 55, 270–276; doi: 10.1038/clpt.1994.27