Side Effects of Trileptal (Oxcarbazepine)
Trileptal (oxcarbazepine) commonly causes central nervous system effects, digestive symptoms, hyponatremia, and skin reactions, with the most frequent side effects being dizziness, somnolence, diplopia, fatigue, nausea, and vomiting. 1
Common Side Effects
Central Nervous System Effects
- Dizziness (28% of patients)
- Somnolence/drowsiness (31%)
- Headache (31%)
- Ataxia (13%)
- Nystagmus (9%)
- Diplopia (double vision) (17%)
- Abnormal vision (13%)
- Tremor (6%)
- Speech disorders (3%)
Gastrointestinal Effects
- Nausea (19%)
- Vomiting (33%)
- Constipation (4%)
- Dyspepsia (2%)
Other Common Side Effects
- Fatigue
- Emotional lability (8%)
- Abnormal gait (8%)
- Rhinitis (10%)
Serious Side Effects
Hyponatremia
- Occurs in approximately 3% of patients
- Can develop gradually during the first months of therapy
- Serum sodium levels below 125 mmol/L have been observed 1, 2
- Usually asymptomatic but can cause headache, confusion, seizures in severe cases
- Risk factors include:
- Renal disease
- Concurrent medications that lower sodium (diuretics, NSAIDs, oral contraceptives)
- Elderly patients
Skin Reactions
- Rash (4%)
- Increased sweating (3%)
- More severe reactions can include:
- Angioedema
- Urticaria
- Stevens-Johnson syndrome (rare)
Hematologic Effects
- Thrombocytopenia (rare)
- Leukopenia (rare) 1
Less Common Side Effects
Cardiovascular
- Bradycardia
- Hypertension
- Hypotension (particularly postural)
- Palpitations
- Syncope
Hepatic
- Elevated liver enzymes
- Increased gamma-GT
Metabolic
- Hyperglycemia
- Hypocalcemia
- Hypokalemia
Neuropsychiatric
- Anxiety
- Depression
- Memory problems (amnesia)
- Aggressive reactions
- Apathy
- Emotional lability
Monitoring Recommendations
No need to measure baseline serum sodium unless:
- Patient has renal disease
- Patient is taking medications that may lower sodium
- Patient has symptoms of hyponatremia 2
During maintenance therapy, measure sodium levels if:
- Medications known to decrease sodium are added
- Symptoms of hyponatremia develop 2
Unlike some other antiepileptic drugs, oxcarbazepine does not require routine monitoring of:
- Complete blood counts
- Liver function tests
- Renal function tests 2
Dosing and Titration
- Adults: Start with 150-600 mg/day, increase by 150-600 mg/day every 2-7 days to reach target dose of 900-1200 mg/day 2
- Children: Start with 8-10 mg/kg/day in 2-3 divided doses, increase by 8-10 mg/kg/day weekly as needed 2
Advantages Over Other Antiepileptic Drugs
- Better tolerated than older antiepileptic drugs
- Lower potential for drug interactions than carbamazepine
- No need for blood level monitoring
- No risk of serious blood dyscrasias that require monitoring 3
Oxcarbazepine has a favorable side effect profile compared to older antiepileptic drugs, but patients should be monitored for hyponatremia and central nervous system effects, particularly during the initial titration period.