Seizure control and side-effect profile after switching adult epileptic patients from standard to extended-release divalproex sodium.
OBJECTIVE
To assess changes in seizure frequency, medication side-effects (especially tremor) and formulation preference after switching patients overnight from immediate-release to extended-release divalproex sodium.


METHODS
Prospective evaluation of consecutive adult outpatients at an urban public hospital who were followed for 6 months after switching drug formulations. Seizure frequency was estimated from patient self-reports. Medication side-effects were monitored with a structured interview (tremor, fatigue, GI upset, hair loss), physician exam (nystagmus, tremor), a drawing test (tremor) and a specific 25-item questionnaire assessing the impact of tremor on activities of daily living.


RESULTS
Forty-seven patients were included in the study but six patients were either lost to follow-up or had insufficient data. Seizure frequency and side-effect profile did not change significantly after switching drug formulations. However, patients had significant subjective improvement in their tremor with the extended-release formulation as assessed by the 25-item questionnaire (p=0.009 at 3 months and p=0.04 at 6 months); other measures of tremor severity showed no change during the 6-month follow-up period. Most patients (71%) preferred the extended-release formulation.


CONCLUSIONS
Patients with epilepsy can be switched overnight from standard to extended-release divalproex sodium, without significant change in seizure frequency and drug side-effect profile. Most patients prefer the extended-release formulation, in part due to subjective decrease in tremor during daily activities.
Pierre-Louis
Serge J C
SJ
Division of Neurology, John H Stroger Jr Hospital of Cook County and Rush Medical College, Chicago, IL 60612, United States. splouis@pol.net
Brannegan
Richard T
RT
Evans
Arthur T
AT
D000203:Activities of Daily Living; D000328:Adult; D000927:Anticonvulsants / Q000008:administration & dosage* / Q000009:adverse effects / Q000627:therapeutic use*; D001835:Body Weight / Q000187:drug effects; D015331:Cohort Studies; D003627:Data Interpretation, Statistical; D003692:Delayed-Action Preparations; D004827:Epilepsy / Q000188:drug therapy*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D017060:Patient Satisfaction; D011446:Prospective Studies; D012640:Seizures / Q000188:drug therapy* / Q000209:etiology; D014202:Tremor / Q000517:prevention & control; D014635:Valproic Acid / Q000008:administration & dosage* / Q000009:adverse effects / Q000627:therapeutic use*; D055815:Young Adult
D000927:Anticonvulsants; D003692:Delayed-Action Preparations; D014635:Valproic Acid