The following adverse reactions have been identified during postapproval use of levetiracetam. Because these reactions are reported voluntarily from a population of uncertain size, it is not always possible to reliably estimate their frequency or establish a causal relationship to drug exposure.
The following adverse reactions have been reported in patients receiving levetiracetam worldwide. The listing is alphabetized: abnormal liver function test, acute kidney injury, anaphylaxis, angioedema, choreoathetosis, drug reaction with eosinophilia and systemic symptoms (DRESS), dyskinesia, erythema multiforme, hepatic failure, hepatitis, hyponatremia, muscular weakness, pancreatitis, pancytopenia (with bone marrow suppression identified in some of these cases), panic attack, thrombocytopenia, and weight loss. Alopecia has been reported with levetiracetam use; recovery was observed in majority of cases where levetiracetam was discontinued.
Levetiracetam blood levels may decrease during pregnancy [ see Warnings and Precautions (5.8) ] .
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. Levetiracetam should be used during pregnancy only if the potential benefit justifies the potential risk to 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 (equivalent to the maximum recommended human dose of 3,000 mg [MRHD] on a mg/m 2 basis) and with increased pup mortality and offspring behavioral alterations at a dose of 1,800 mg/kg/day (6 times the MRHD on a mg/m 2 basis). The developmental no effect dose was 70 mg/kg/day (0.2 times the MRHD on a mg/m 2 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 (4 times MRHD on a mg/m 2 basis) and in decreased fetal weights and increased incidences of fetal malformations at a dose of 1,800 mg/kg/day (12 times the MRHD on a mg/m 2 basis). The developmental no effect dose was 200 mg/kg/day (equivalent to the MRHD on a mg/m 2 basis). Maternal toxicity was also observed at 1,800 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 3,600 mg/kg/day (12 times the MRHD). 1,200 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 during the last third of gestation and throughout lactation produced no adverse developmental or maternal effects at doses of up to 1,800 mg/kg/day (6 times the MRHD on a mg/m 2 basis).
To provide information regarding the effects of in utero exposure to levetiracetam, physicians are advised to recommend that pregnant patients taking levetiracetam enroll in the North American Antiepileptic Drug (NAAED) pregnancy registry. This can be done by calling the toll free number 1-888-233-2334, and must be done by the patients themselves. Information on the registry can also be found at the website http://www.aedpregnancyregistry.org/.
The effect of levetiracetam on labor and delivery in humans is unknown.
Levetiracetam is excreted in human milk. Because of the potential for serious adverse reactions in nursing infants from levetiracetam, a decision should be made whether to discontinue nursing or discontinue the drug, taking into account the importance of the drug to the mother.
The safety and effectiveness of levetiracetam in the adjunctive treatment of partial onset seizures in pediatric patients age 1 month to 16 years with epilepsy have been established [ see Clinical Studies (14.1) ]. The dosing recommendation in these pediatric patients varies according to age group and is weight-based [ see Dosage and Administration (2.6) ].
The safety and effectiveness of levetiracetam as adjunctive treatment of myoclonic seizures in adolescents 12 years of age and older with juvenile myoclonic epilepsy have been established [ see Clinical Studies (14.2) ].
The safety and effectiveness of levetiracetam as adjunctive therapy in the treatment of primary generalized tonic-clonic seizures in pediatric patients 6 years of age and older with idiopathic generalized epilepsy have been established [ see Clinical Studies (14.3) ].
A 3-month, randomized, double-blind, placebo-controlled study was performed to assess the neurocognitive and behavioral effects of levetiracetam as adjunctive therapy in 98 (levetiracetam N=64, placebo N=34) pediatric patients, ages 4 years to 16 years, with partial seizures that were inadequately controlled. The target dose was 60 mg/kg/day . Neurocognitive effects were measured by the Leiter-R Attention and Memory (AM) Battery, which measures various aspects of a child’s memory and attention. Although no substantive differences were observed between the placebo and drug treated groups in the median change from baseline in this battery, the study was not adequate to assess formal statistical non-inferiority of the drug and placebo. The Achenbach Child Behavior Checklist (CBCL/6-18), a standardized validated tool used to assess a child’s competencies and behavioral/emotional problems, was also assessed in this study. An analysis of the CBCL/6-18 indicated, on average, a worsening in levetiracetam-treated patients in aggressive behavior, one of the eight syndrome scores [ see Warnings and Precautions (5.1)].
Studies of levetiracetam in juvenile rats (dosing from day 4 through day 52 of age) and dogs (dosing from week 3 through week 7 of age) at doses of up to 1,800 mg/kg/day (approximately 7 and 24 times, respectively, the maximum recommended pediatric dose of 60 mg/kg/day on a mg/m 2 basis) did not indicate a potential for age-specific toxicity.
There were 347 subjects in clinical studies of levetiracetam that were 65 years old and over. No overall differences in safety were observed between these subjects and younger subjects. There were insufficient numbers of elderly subjects in controlled trials of epilepsy to adequately assess the effectiveness of levetiracetam in these patients.
Levetiracetam is known to be substantially excreted by the kidney, and the risk of adverse reactions to this drug may be greater in patients with impaired renal function. Because elderly patients are more likely to have decreased renal function, care should be taken in dose selection, and it may be useful to monitor renal function [ see Clinical Pharmacology (12.3) ].
Clearance of levetiracetam is decreased in patients with renal impairment and is correlated with creatinine clearance [ see Clinical Pharmacology (12.3) ]. Dosage adjustment is recommended for patients with impaired renal function and supplemental doses should be given to patients after dialysis [ see Dosage and Administration (2.7) ].
The highest known dose of oral levetiracetam received in the clinical development program was 6,000 mg/day. Other than drowsiness, there were no adverse reactions in the few known cases of overdose in clinical trials. Cases of somnolence, agitation, aggression, depressed level of consciousness, respiratory depression, and coma were observed with levetiracetam overdoses in postmarketing use.
There is no specific antidote for overdose with levetiracetam. If indicated, elimination of unabsorbed drug should be attempted by emesis or gastric lavage; usual precautions should be observed to maintain airway. General supportive care of the patient is indicated including monitoring of vital signs and observation of the patient’s clinical status. A Certified Poison Control Center should be contacted for up to date information on the management of overdose with levetiracetam.
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