Does It Really Matter When a Blood Sample for Valproic Acid Concentration is Taken Following Once-Daily Administration of Divalproex-ER?

摘要: Divalproex sodium extended-release (divalproex-ER) is a novel formulation intended for once-daily oral administration, either morning or evening. Questions have risen concerning the optimal time obtaining blood sample valproic acid (VPA) concentration in relation to dose. Trough sampling easily achieved just before daily dose, but best after an evening dose unclear, because collecting 21 24 hours later may be limited by operational of laboratory. This investigation provides practical guidance regarding timing. Steady-state plasma VPA concentration-time profiles from 5 published divalproex-ER studies (healthy subjects and epilepsy patients) were analyzed. The profile each subject/patient was expressed as percentage his/her trough summary statistics computed. Typically, when taking once morning, collected expected within 3% value. Conversely, dosed evening, example 8 PM, draw 12 15 (ie, 11 AM) will give value that 18% 25% higher, on average, than However, waiting longer, (for 18 hours, ie 2 PM) result values are merely 13% higher values, which provide acceptable information monitoring purposes. greatest deviation occurs around peak, 3 dose; during this period recommended only if clinical need exists test concentration. Despite apparent smoothness timing does matter impacts proper interpretation