The pharmacokinetics and pharmacodynamics of Procysteine in amyotrophic lateral sclerosis

In 13 subjects with ALS, we studied the safety and pharmacokinetic properti es of Procysteine, a cysteine prodrug that increases levels of intracellula r glutathione. We found that oral administration of Procysteine was safe. P rocysteine enters CSF after both IV and oral dosing and accumulates to sign ificant levels in CSF. We also observed that CSF levels of glutathione fall dramatically with aging.