Tolerability of oral loading of divalproex sodium in child psychiatry inpatients.
OBJECTIVE
To determine a well-tolerated oral load of divalproex sodium that quickly and reliably achieves therapeutic drug levels in child psychiatry inpatients.


METHODS
A retrospective chart review revealed that during a 6-month period, divalproex sodium therapy was initiated in 16 male inpatients (ages 5-14 years). The patients were divided into two groups based on the initial dosing regimen. The first group received approximately 15 mg/kg/day based on actual weight, and the second group received approximately 15 mg/kg/day based on an adjusted ideal body weight (IBW). Weight was adjusted in these patients according to the following formula: IBW + 40% (Observed Weight - IBW). A trough blood level was obtained on day 5 of therapy.


RESULTS
Initial drug levels ranged from 46-146 ug/mL (mean = 90.6), of which 13 of 16 (81.3%) were considered within therapeutic range (50-120 ug/mL). Eight of 16 patients (50%) had reported side effects, including sedation and gastrointestinal upset. The majority of these side effects occurred in patients with drug levels > or = 90 ug/mL and were noted to improve with 1-2 days of therapy +/- dosage adjustment. Overweight patients (> or = 15% above IBW) who received the unadjusted 15 mg/kg oral load had significantly higher drug levels than their normal weight counterparts and overweight children who received weight-adjusted dosing (p < 0.003).


CONCLUSIONS
A 15 mg/kg/day oral load of divalproex sodium resulted in therapeutic drug levels on day 5 of treatment and is well tolerated in normal weight children. Overweight children are significantly more likely to experience supratherapeutic drug levels on this regimen, which may affect tolerability. Overweight children appear to benefit from weight-adjusted oral loading.
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Division of Child and Adolescent Psychiatry, The Pennsylvania State University College of Medicine, Hershey 17033, USA. dgood17@juno.com
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D018692:Antimanic Agents / Q000009:adverse effects* / Q000097:blood / Q000627:therapeutic use; D001835:Body Weight; D002648:Child; D002675:Child, Preschool; D006801:Humans; D007297:Inpatients; D008297:Male; D009765:Obesity / Q000378:metabolism; D012189:Retrospective Studies; D014635:Valproic Acid / Q000009:adverse effects* / Q000097:blood / Q000627:therapeutic use
D018692:Antimanic Agents; D014635:Valproic Acid