Single dose pharmacokinetics of HEPP, a new anticonvulsant in normal healthy volunteers

The pharmacokinetics and the dose proportionality of a new anticonvulsant c ompound, HEPP (D,L-3-hydroxy-3-ethyl-3-phenylpropionamide) was studied in h ealthy male volunteers as part of the pharmacological evaluation for new dr ugs. Study was performed administering doses of 250, 375, 500 and 625 mg of HEPP to six male volunteers. Blood and urine samples were collected for 72 h postdose and analysed by HPLC. Results showed that in man HEPP is rapidl y absorbed from the gastrointestinal tract. T-max values were between 1.5 a nd 6.0 h. Plasma mean terminal half-life after the different doses ranged b etween 15.83 and 27.62 h with an overall harmonic mean value of 22.8. The m ean AUC(0-infinity) and C-max increased linearly with doses of 250, 375 and 500 mg but not with the dose of 625 mg. The amount of unchanged drug excre ted in urine was between 3 and 6% of administered dose which shows an exten sive metabolism of the drug. (C) 1998 John Wiley & Sons, Ltd.