Partial-onset seizures (adjunct). Primary generalized tonic-clonic seizures in patients 6 years of age and older. Myoclonic seizures in adults with myoclonic epilepsy (adjunct).
Appears to inhibit burst firing without affecting normal neuronal excitability and may selectively prevent hypersynchronization of epileptiform burst firing and propagation of seizure activity. Therapeutic Effects: Decreased incidence and severity of seizures.
Adverse Reactions/Side Effects
CNS: dizziness, fatigue/somnolence, weakness, behavioral abnormalities. Neuro: coordination difficulties (adults only).
PHYSICAL THERAPY IMPLICATIONS
Examination and Evaluation
Document the number, duration, and severity of seizures to help determine if this drug is effective in reducing seizure activity.
Assess dizziness or weakness that might affect gait, balance, and other functional activities (See Appendix C). Report balance problems and functional limitations to the physician, and caution the patient and family/caregivers to guard against falls and trauma.
Monitor daytime drowsiness, somnolence, or other changes in behavior. Repeated or excessive symptoms may require change in dose or medication.
Assess any incoordination to rule out neuromusculoskeletal pathology; that is, try to determine if incoordination is drug induced rather than caused by neurologic or musculoskeletal problems.
Guard against falls and trauma (hip fractures, head injury, and so forth), especially if dizziness or incoordination affect gait and balance. Implement fall-prevention strategies, especially if balance is impaired (See Appendix E).
Advise patient to avoid alcohol and other CNS depressants because of the increased risk of sedation and adverse effects.
Advise patients on prolonged antiseizure therapy not to discontinue medication without consulting their physician. Abrupt withdrawal may cause increased seizures.
Advise patient about the risk of daytime drowsiness and decreased attention and mental focus. Use care if driving or in other activities that require strong concentration and fast responses.
Absorption: Rapidly and completely absorbed following oral administration.
Metabolism and Excretion: 66% excreted unchanged by the kidneys; some metabolism by the liver (metabolites inactive).
Half-life: 7.1 hr (increased in renal impairment).
Contraindicated in: Hypersensitivity; OB: Lactation.
Use Cautiously in: Geri: Renal elimination decreased; dose reduction may be necessary; Renal impairment (dose reduction recommended if CCr ≤80 mL/min); Pedi: Children <4 yr (safety not established); OB: Use only during pregnancy if potential benefit justifies potential risk to fetus.