Levitski R E, Trepanier L A
Department of Medical Sciences, School of Veterinary Medicine, University of Wisconsin, Madison 53706, USA.
J Am Vet Med Assoc. 2000 Jul 15;217(2):200-4. doi: 10.2460/javma.2000.217.200.
To determine whether there are therapeutically relevant changes in serum phenobarbital concentrations throughout a daily dosing interval in epileptic dogs receiving phenobarbital for > or = 3 weeks.
Prospective study.
33 epileptic dogs receiving phenobarbital.
Serum phenobarbital concentrations were measured at 0 hour (trough), 3 hours, and 6 hours after oral administration of phenobarbital in epileptic dogs that had received phenobarbital twice daily for a minimum of 3 weeks. For each dog, trough, 3-hour, and 6-hour serum phenobarbital concentrations were evaluated to determine whether they were within the same therapeutic category (lower, middle, or upper end of the therapeutic range of 15 to 45 micrograms/ml), or whether there was a > 30% change in serum concentrations throughout the day.
Ninety-one percent (30/33) of dogs had trough, 3-hour, and 6-hour serum phenobarbital concentrations in the same therapeutic category. Only 9% (3/33) of dogs had trough, 3-hour, and 6-hour serum concentrations in different therapeutic categories with a > 30% change in concentrations throughout the day. Significant differences were not detected among mean serum phenobarbital concentrations when comparing the trough, 3-hour, and 6-hour samples for all dogs.
There is no therapeutically relevant change in serum phenobarbital concentrations throughout a daily dosing interval in most epileptic dogs. Therefore, timing is not important when collecting blood samples to measure serum phenobarbital concentrations in most epileptic dogs treated long-term with phenobarbital.
确定接受苯巴比妥治疗≥3周的癫痫犬在每日给药间隔期间血清苯巴比妥浓度是否存在具有治疗意义的变化。
前瞻性研究。
33只接受苯巴比妥治疗的癫痫犬。
在癫痫犬中，于口服苯巴比妥后0小时（谷浓度）、3小时和6小时测量血清苯巴比妥浓度，这些癫痫犬每日接受两次苯巴比妥治疗至少3周。对每只犬的谷浓度、3小时和6小时血清苯巴比妥浓度进行评估，以确定它们是否处于同一治疗类别（治疗范围15至45微克/毫升的下限、中间或上限），或者全天血清浓度是否有>30%的变化。
91%（30/33）的犬的谷浓度、3小时和6小时血清苯巴比妥浓度处于同一治疗类别。仅9%（3/33）的犬的谷浓度、3小时和6小时血清浓度处于不同治疗类别，且全天浓度变化>30%。在比较所有犬的谷浓度、3小时和6小时样本时，未检测到平均血清苯巴比妥浓度之间的显著差异。
大多数癫痫犬在每日给药间隔期间血清苯巴比妥浓度没有具有治疗意义的变化。因此，对于大多数长期接受苯巴比妥治疗的癫痫犬，采集血样测量血清苯巴比妥浓度时，采血时间并不重要。
