Kinetics of thiamin and thiamin phosphate esters in human blood, plasma and urine after 50 mg intravenously or orally

✍ Scribed by C. M. E. Tallaksen; A. Sande; T. Bøhmer; H. Bell; J. Karlsen

• Book ID: 104719084
• Publisher: Springer
• Year: 1993
• Tongue: English
• Weight: 587 KB
• Volume: 44
• Category: Article
• ISSN: 0031-6970
• DOI: 10.1007/bf00315284

✦ Synopsis

The concentrations of thiamin and thiamin monophosphate and diphosphate in plasma and whole blood samples were assessed in six healthy subjects for 12 h and in urine for 24 h following an IV and PO bolus dose of 50 mg thiamin HCl. Unphosphorylated thiamin increased rapidly in plasma after IV administration and then decreased to its initial value within 12 h in all but one subject; the half-life was 96 min. Thiamin mono and -diphosphate increased moderately (56%), and decreased slowly; the half-life of diphosphate was 664 min. Within 24 h, 53% of the administered dose was recovered in the urine, indicating a restricted distribution. After oral administration, the peak thiamin concentration in plasma was reached after 53 min and the concentration then had increased to 179% of its initial value. The elimination half-life was 154 min, and only 2.5% of the given dose was recovered in the urine. The relative bioavailability of thiamin was 5.3%. A moderate amount of the administered thiamin was stored in blood. Other body tissues must play an important part, therefore, in the distribution of thiamin.