title: A phase I, pharmacokinetic, dosage escalation study of creatine monohydrate in subjects with amyotrophic lateral sclerosis.
abstract: Creatine monohydrate (creatine) has potential neuroprotective properties and is a commonly used supplement in amyotrophic lateral sclerosis (ALS) and other neurodegenerative disorders. Minimum therapeutic and maximum tolerated dosages of creatine are not yet known, nor is it known what systemic plasma concentrations result from specific dosage regimens. The objectives of this study were to establish steady-state plasma pharmacokinetics of creatine at several dosages, and to evaluate the effects of creatine on brain metabolites using proton magnetic resonance spectroscopy ((1)H-MRS). Six participants with ALS received creatine at three weekly escalating oral dosages (5, 10, and 15 g b.i.d.). Plasma creatine levels and MR spectra were obtained at baseline and with each dosage increase. Mean pre-dose steady-state creatine plasma concentrations were 20.3, 39.3, and 61.5 ug/ml at 5, 10, and 15 g b.i.d., respectively. Creatine spectra increased by 8% (p = 0.06) and glutamate + glutamine signals decreased by 17% (p = 0.039) at higher dosages. There were no safety concerns at any of the dosages. In conclusion, creatine plasma concentrations increased in a dose-dependent manner. Creatine appears to cross the blood-brain barrier, and oral administration of 15 g b.i.d. is associated with increased in vivo brain creatine concentrations and decreased glutamate concentrations.
authors.affiliation: Neurology Clinical Trials Unit (NCTU), Massachusetts General Hospital, 13th Street, Charlestown, MA 02129, USA. NATASSI@PARTNERS.ORG
authors.forename: Nazem
authors.initials: N
authors.lastname: Atassi
authors.forename: Eva-Maria
authors.initials: EM
authors.lastname: Ratai
authors.forename: David J
authors.initials: DJ
authors.lastname: Greenblatt
authors.forename: Darlene
authors.initials: D
authors.lastname: Pulley
authors.forename: Yanli
authors.initials: Y
authors.lastname: Zhao
authors.forename: Jeffery
authors.initials: J
authors.lastname: Bombardier
authors.forename: Stuart
authors.initials: S
authors.lastname: Wallace
authors.forename: Joanna
authors.initials: J
authors.lastname: Eckenrode
authors.forename: Merit
authors.initials: M
authors.lastname: Cudkowicz
authors.forename: Allitia
authors.initials: A
authors.lastname: Dibernardo
mesh_terms: D000328:Adult; D000368:Aged; D000690:Amyotrophic Lateral Sclerosis / Q000188:drug therapy*; D001921:Brain / Q000033:anatomy & histology / Q000378:metabolism; D003401:Creatine / Q000097:blood* / Q000493:pharmacokinetics* / Q000627:therapeutic use*; D004305:Dose-Response Relationship, Drug; D005260:Female; D018698:Glutamic Acid / Q000378:metabolism; D005973:Glutamine / Q000378:metabolism; D006801:Humans; D009682:Magnetic Resonance Spectroscopy; D008297:Male; D008875:Middle Aged; D018696:Neuroprotective Agents / Q000627:therapeutic use*
chemical_list: D018696:Neuroprotective Agents; D005973:Glutamine; D018698:Glutamic Acid; D003401:Creatine