Neuropsychiatric Adverse Reactions
KEPPRA XR Tablets
In some patients experiencing partial onset seizures, KEPPRA XR causes somnolence, dizziness, and behavioral abnormalities.
In the KEPPRA XR double-blind, controlled trial in patients experiencing partial onset seizures, 7.8% of KEPPRA XR-treated patients experienced somnolence compared to 2.5% of placebo-treated patients. Dizziness was reported in 5.2% of KEPPRA XR-treated patients compared to 2.5% of placebo-treated patients.
A total of 6.5% of KEPPRA XR-treated patients experienced non-psychotic behavioral disorders (reported as irritability and aggression) compared to 0% of placebo-treated patients. Irritability was reported in 6.5% of KEPPRA XR-treated patients. Aggression was reported in 1.3% of KEPPRA XR-treated patients.
No patient discontinued treatment or had a dose reduction as a result of these adverse reactions.
The number of patients exposed to KEPPRA XR was considerably smaller than the number of patients exposed to immediate-release KEPPRA tablets in controlled trials. Therefore, certain adverse reactions observed in the immediate-release KEPPRA controlled trials may also occur in patients receiving KEPPRA XR.
Immediate-Release KEPPRA Tablets
In controlled trials of immediate-release KEPPRA tablets in patients experiencing partial onset seizures, immediate-release KEPPRA causes the occurrence of central nervous system adverse reactions that can be classified into the following categories: 1) somnolence and fatigue, 2) coordination difficulties, and 3) behavioral abnormalities.
In controlled trials of adult patients with epilepsy experiencing partial onset seizures, 14.8% of immediate-release KEPPRA-treated patients reported somnolence, compared to 8.4% of placebo patients. There was no clear dose response up to 3000 mg/day.
In controlled trials of adult patients with epilepsy experiencing partial onset seizures, 14.7% of treated patients reported asthenia, compared to 9.1% of placebo patients.
A total of 3.4% of immediate-release KEPPRA-treated patients experienced coordination difficulties, (reported as either ataxia, abnormal gait, or incoordination) compared to 1.6% of placebo patients.
Somnolence, asthenia and coordination difficulties occurred most frequently within the first 4 weeks of treatment.
In controlled trials of patients with epilepsy experiencing partial onset seizures, 5 (0.7%) immediate-release KEPPRA-treated patients experienced psychotic symptoms compared to 1 (0.2%) placebo patient.
A total of 13.3% of immediate-release KEPPRA patients experienced other behavioral symptoms (reported as aggression, agitation, anger, anxiety, apathy, depersonalization, depression, emotional lability, hostility, irritability, etc.) compared to 6.2% of placebo patients.
Antiepileptic drugs, including KEPPRA XR, should be withdrawn gradually to minimize the potential of increased seizure frequency.
Although there were no obvious hematologic abnormalities observed in treated patients in the KEPPRA XR controlled study, the limited number of patients makes any conclusion tentative. The data from the partial seizure patients in the immediate-release KEPPRA controlled studies should be considered to be relevant for KEPPRA XR-treated patients.
In controlled trials of immediate-release KEPPRA tablets in patients experiencing partial onset seizures, minor, but statistically significant, decreases compared to placebo in total mean RBC count (0.03 x 106/mm3), mean hemoglobin (0.09 g/dL), and mean hematocrit (0.38%), were seen in immediate-release KEPPRA-treated patients. A total of 3.2% of treated and 1.8% of placebo patients had at least one possibly significant (≤2.8 x 109/L) decreased WBC, and 2.4% of treated and 1.4% of placebo patients had at least one possibly significant (≤1.0 x 109/L) decreased neutrophil count. Of the treated patients with a low neutrophil count, all but one rose towards or to baseline with continued treatment. No patient was discontinued secondary to low neutrophil counts.
There were no meaningful changes in mean liver function tests (LFT) in the KEPPRA XR controlled trial. No patients were discontinued from the controlled trial for LFT abnormalities.
There were no meaningful changes in mean liver function tests (LFT) in controlled trials of immediate-release KEPPRA tablets in adult patients; lesser LFT abnormalities were similar in drug and placebo-treated patients in controlled trials (1.4%). No patients were discontinued from controlled trials for LFT abnormalities except for 1 (0.07%) adult epilepsy patient receiving open treatment.
Although effects on laboratory tests were not clinically significant with KEPPRA XR treatment, it is expected that the data from immediate-release KEPPRA tablets controlled studies would be considered relevant for KEPPRA XR-treated patients.
Although most laboratory tests are not systematically altered with immediate-release KEPPRA treatment, there have been relatively infrequent abnormalities seen in hematologic parameters and liver function tests.
USE IN SPECIFIC POPULATIONS
Pregnancy Category C
There are no adequate and well-controlled studies in pregnant women. In animal studies, levetiracetam produced evidence of developmental toxicity, including teratogenic effects, at doses similar to or greater than human therapeutic doses. KEPPRA XR should be used during pregnancy only if the potential benefit justifies the potential risk to the fetus. As with other antiepileptic drugs, physiological changes during pregnancy may affect levetiracetam concentration. There have been reports of decreased levetiracetam concentration during pregnancy. Discontinuation of antiepileptic treatments may result in disease worsening, which can be harmful to the mother and the fetus.
Oral administration of levetiracetam to female rats throughout pregnancy and lactation led to increased incidences of minor fetal skeletal abnormalities and retarded offspring growth pre- and/or postnatally at doses ≥350 mg/kg/day (approximately equivalent to the maximum recommended human dose of 3000 mg [MRHD] on a mg/m2 basis) and with increased pup mortality and offspring behavioral alterations at a dose of 1800 mg/kg/day (6 times the MRHD on a mg/m2 basis). The developmental no effect dose was 70 mg/kg/day (0.2 times the MRHD on a mg/m2 basis). There was no overt maternal toxicity at the doses used in this study.
Oral administration of levetiracetam to pregnant rabbits during the period of organogenesis resulted in increased embryofetal mortality and increased incidences of minor fetal skeletal abnormalities at doses ≥600 mg/kg/day (approximately 4 times MRHD on a mg/m2 basis) and in decreased fetal weights and increased incidences of fetal malformations at a dose of 1800 mg/kg/day (12 times the MRHD on a mg/m2 basis). The developmental no effect dose was 200 mg/kg/day (1.3 times the MRHD on a mg/m2 basis). Maternal toxicity was also observed at 1800 mg/kg/day.
When levetiracetam was administered orally to pregnant rats during the period of organogenesis, fetal weights were decreased and the incidence of fetal skeletal variations was increased at a dose of 3600 mg/kg/day (12 times the MRHD). 1200 mg/kg/day (4 times the MRHD) was a developmental no effect dose. There was no evidence of maternal toxicity in this study.
Treatment of rats with levetiracetam during the last third of gestation and throughout lactation produced no adverse developmental or maternal effects at oral doses of up to 1800 mg/kg/day (6 times the MRHD on a mg/m2 basis).
|Page last updated: 2009-05-21||