Side Effects of Trileptal (Oxcarbazepine)
The most common side effects of Trileptal include dizziness, sleepiness, double vision, nausea, vomiting, problems with coordination, and trembling, with central nervous system and gastrointestinal effects being most frequent. 1
Most Common Side Effects
The FDA-approved labeling identifies the following most frequent adverse effects 1:
- Dizziness - among the most commonly reported 1, 2
- Somnolence and tiredness - frequently causes sedation 1, 3
- Double vision (diplopia) - common visual disturbance 1, 3
- Nausea and vomiting - gastrointestinal effects are frequent 1, 2, 3
- Problems with walking and coordination (ataxia/unsteadiness) - motor coordination issues 1, 2
- Trembling - neurological manifestation 1
- Headache - commonly reported 2, 4
- Rash - skin reactions occur 1, 3
These effects are typically mild to moderate in severity and are generally well-tolerated, with most patients (95.3%) continuing therapy 5.
Serious Adverse Effects Requiring Immediate Medical Attention
Life-Threatening Reactions
Hyponatremia (low sodium) is a significant concern with oxcarbazepine, occurring more frequently than with carbamazepine 2, 3. This requires monitoring of serum sodium levels, particularly during initial treatment.
Serious skin reactions can occur, including Stevens-Johnson syndrome and toxic epidermal necrolysis, which are potentially fatal 1. Patients should discontinue the medication immediately if rash develops.
Increased seizure frequency can paradoxically occur, especially in children, requiring immediate medical evaluation 1.
Neurological and Psychiatric Effects
- Suicidal thoughts or behavior - antiepileptic drugs including oxcarbazepine carry this risk 1
- Trouble concentrating and confusion 1
- Problems with speech and language 1
- Worsening of seizures 1
Metabolic and Laboratory Abnormalities
Hyponatremia represents the most clinically significant metabolic disturbance, with increased risk compared to carbamazepine 2, 3. Long-term monitoring of sodium levels is essential 3.
Drug Interactions and Special Considerations
Oral contraceptive efficacy may be reduced - patients should use alternative or additional contraceptive methods 1.
Pregnancy considerations - oxcarbazepine may harm the unborn baby, and patients should enroll in the North American Antiepileptic Drug Pregnancy Registry 1.
Breastfeeding - oxcarbazepine passes into breast milk 1.
Comparative Safety Profile
Oxcarbazepine demonstrates better tolerability than older antiepileptic drugs with fewer drug interactions, less enzyme induction, and no production of toxic epoxide metabolites seen with carbamazepine 6, 2. The frequency and severity of drug interactions are significantly less than with carbamazepine or other traditional antiepileptic agents 2.
In clinical trials, adverse effects were observed in only 11.2% of patients, with 40% of these cases not clearly related to the drug 5.
Critical Safety Warnings
Do not stop oxcarbazepine suddenly - abrupt discontinuation can cause status epilepticus (seizures that will not stop) 1.
Avoid alcohol and sedating medications - combined use increases drowsiness and dizziness 1.
Do not drive or operate machinery until you know how the medication affects you, as it may slow thinking and motor skills 1.
Monitoring Recommendations
While not explicitly detailed in the FDA labeling for oxcarbazepine, clinical practice suggests monitoring serum sodium levels, particularly in the first few months of therapy, given the increased risk of hyponatremia compared to other antiepileptic drugs 2, 3.