Theophylline therapeutic drug monitoring in the case of a new sustained-release pellet formulation for once-daily evening administration.
In view of the large interindividual differences in theophylline clearance and the narrow therapeutic range it is essential to individualize the theophylline dose. In order to do so, estimation of minimum and maximum serum theophylline concentrations during one dosing interval from one or two blood samples is desirable, particularly in the case of once-daily administration. Whereas the minimum (trough) concentration can be readily estimated from the pre-dose level, the maximum (peak) concentration occurs at night. For Euphylong, a new sustained-release theophylline pellet formulation, administered once-daily in the evening, for example between 7 p.m. and 8 p.m., the nocturnal maximum concentration can be calculated as 110-120% of the serum theophylline concentration determined from a blood sample taken in the early morning, for example between 7 a.m. and 8 a.m. This procedure works not only for mean data but also on an individual basis. The procedure is based on the extended nocturnal plateau profile of Euphylong with its high reproducibility and cannot be transferred to other formulations.
Steinijans
V W
VW
Department of Biometry, Byk Gulden Research Center, Konstanz, Fed. Rep. of Germany.
Trautmann
H
H
Sauter
R
R
Staudinger
H
H
D003692:Delayed-Action Preparations; D006801:Humans; D008991:Monitoring, Physiologic; D013806:Theophylline / Q000008:administration & dosage / Q000097:blood / Q000493:pharmacokinetics*
D003692:Delayed-Action Preparations; D013806:Theophylline