Oxcarbazepine (oxcarbazepine 150 mg) Dailymed

Recent Major Changes Section

1 Indications And Usage

Oxcarbazepine tablets, USP are indicated for use as monotherapy or adjunctive therapy in the treatment of partial-onset seizures in adults and as monotherapy in the treatment of partial-onset seizures in pediatric patients aged 4 years and above, and as adjunctive therapy in pediatric patients aged 2 years and above with partial-onset seizures.


Oxcarbazepine tablets are indicated for:

• Adults: Monotherapy or adjunctive therapy in the treatment of partial-onset seizures
• Pediatrics:
  - Monotherapy in the treatment of partial-onset seizures in children 4 to 16 years
  
  - Adjunctive therapy in the treatment of partial-onset seizures in children 2 to 16 years (1)
  

2 Dosage And Administration

Adults: initiate with a dose of 600 mg/day, given twice-a-day 

• Adjunctive Therapy: Maximum increment of 600 mg/day at approximately weekly intervals. The recommended daily dose is 1,200 mg/day (2.1)
• Conversion to Monotherapy: withdrawal concomitant over 3 to 6 weeks; reach maximum dose of oxcarbazepine tablets in 2 to 4 weeks with increments of 600 mg/day at weekly intervals to a recommended daily dose of 2,400 mg/day (2.2)
• Initiation of Monotherapy: Increments of 300 mg/day every third day to a dose of 1,200 mg/day. (2.3)
• Initiate at one-half the usual starting dose and increase slowly in patients with a creatinine clearance <30 mL/min (2.7)

Pediatrics: initiation with 8 to 10 mg/kg/day, given twice-a-day. For patients aged 2 to <4 years and under 20 kg, a starting dose of 16 to 20 mg/kg/day may be considered. Recommended daily dose is dependent upon patient weight.

• Adjunctive Patients (Aged 2 to 16 Years): For patients aged 4 to 16 years, target maintenance dose should be achieved over 2 weeks (2.4). For patients aged 2 to <4 years, maximum maintenance dose should be achieved over 2 to 4 weeks and should not to exceed 60 mg/kg/day (2.4)
• Conversion to Monotherapy for Patients (Aged 4 to 16 Years): Maximum increment of 10 mg/kg/day at weekly intervals, concomitant antiepileptic drugs can be completely withdrawn over 3 to 6 weeks (2.5)
• Initiation of Monotherapy for Patients (Aged 4 to 16 Years): Increments of 5 mg/kg/day every third day (2.6)

2.1 Adjunctive Therapy for Adults

Initiate oxcarbazepine tablets with a dose of 600 mg/day, given twice-a-day. If clinically indicated, the dose may be increased by a maximum of 600 mg/day at approximately weekly intervals; the maximum recommended daily dose is 1,200 mg/day. Daily doses above 1,200 mg/day show somewhat greater effectiveness in controlled trials, but most patients were not able to tolerate the 2,400 mg/day dose, primarily because of CNS effects.  

Dosage adjustment is recommended with concomitant use of strong CYP3A4 enzyme inducers or UGT inducers, which include certain antiepileptic drugs (AEDs) [see Drug Interactions (7.1, 7.2)].

2.2 Conversion to Monotherapy for Adults

Patients receiving concomitant AEDs may be converted to monotherapy by initiating treatment with oxcarbazepine tablets at 600 mg/day (given in a twice-a-day regimen) while simultaneously initiating the reduction of the dose of the concomitant AEDs. The concomitant AEDs should be completely withdrawn over 3 to 6 weeks, while the maximum dose of oxcarbazepine tablets should be reached in about 2 to 4 weeks. Oxcarbazepine tablets may be increased as clinically indicated by a maximum increment of 600 mg/day at approximately weekly intervals to achieve the maximum recommended daily dose of 2,400 mg/day. A daily dose of 1,200 mg/day has been shown in one study to be effective in patients in whom monotherapy has been initiated with oxcarbazepine tablets. Patients should be observed closely during this transition phase.

2.3 Initiation of Monotherapy for Adults

Patients not currently being treated with AEDs may have monotherapy initiated with oxcarbazepine tablets. In these patients, initiate oxcarbazepine tablets at a dose of 600 mg/day (given a twice-a-day); the dose should be increased by 300 mg/day every third day to a dose of 1,200 mg/day. Controlled trials in these patients examined the effectiveness of a 1,200 mg/day dose; a dose of 2,400 mg/day has been shown to be effective in patients converted from other AEDs to oxcarbazepine tablets monotherapy (see above).

2.4 Adjunctive Therapy for Pediatric Patients (Aged 2 to 16 Years)

In pediatric patients aged 4 to 16 years, initiate oxcarbazepine tablets at a daily dose of 8 to 10 mg/kg generally not to exceed 600 mg/day, given twice-a-day. The target maintenance dose of oxcarbazepine tablets should be achieved over two weeks, and is dependent upon patient weight, according to the following chart:

20 to 29 kg - 900 mg/day

29.1 to 39 kg - 1,200 mg/day

>39 kg - 1800 mg/day

In the clinical trial, in which the intention was to reach these target doses, the median daily dose was 31 mg/kg with a range of 6 to 51 mg/kg.

In pediatric patients aged 2 to <4 years, initiate oxcarbazepine tablets at a daily dose of 8 to 10 mg/kg generally not to exceed 600 mg/day, given twice-a-day. For patients less than 20 kg, a starting dose of 16 to 20 mg/kg may be considered [see Clinical Pharmacology (12.3)]. The maximum maintenance dose of oxcarbazepine tablets should be achieved over 2 to 4 weeks and should not exceed 60 mg/kg/day in a twice-a-day regimen.

In the clinical trial in pediatric patients (2 to 4 years of age) in which the intention was to reach the target dose of 60 mg/kg/day, 50% of patients reached a final dose of at least 55 mg/kg/day.

Under adjunctive therapy (with and without enzyme-inducing AEDs), when normalized by body weight, apparent clearance (L/hr/kg) decreased when age increased such that children 2 to <4 years of age may require up to twice the oxcarbazepine dose per body weight compared to adults; and children 4 to ≤12 years of age may require a 50% higher oxcarbazepine dose per body weight compared to adults.

Dosage adjustment is recommended with concomitant use of strong CYP3A4 enzyme inducers or UGT inducers, which include certain antiepileptic drugs (AEDs) [see Drug Interactions (7.1, 7.2)].

2.5 Conversion to Monotherapy for Pediatric Patients (Aged 4 to 16 Years)

Patients receiving concomitant antiepileptic drugs may be converted to monotherapy by initiating treatment with oxcarbazepine tablets at approximately 8 to 10 mg/kg/day given twice-a-day, while simultaneously initiating the reduction of the dose of the concomitant antiepileptic drugs. The concomitant antiepileptic drugs can be completely withdrawn over 3 to 6 weeks while oxcarbazepine tablets may be increased as clinically indicated by a maximum increment of 10 mg/kg/day at approximately weekly intervals to achieve the recommended daily dose. Patients should be observed closely during this transition phase.  

The recommended total daily dose of oxcarbazepine tablets is shown in Table 1.

2.6 Initiation of Monotherapy for Pediatric Patients (Aged 4 to 16 Years)

Patients not currently being treated with antiepileptic drugs may have monotherapy initiated with oxcarbazepine tablets. In these patients, initiate oxcarbazepine tablets at a dose of 8 to 10 mg/kg/day given twice-a-day. The dose should be increased by 5 mg/kg/day every third day to the recommended daily dose shown in the table below.

Table 1: Range of Maintenance Doses of Oxcarbazepine for Pediatrics by Weight During Monotherapy
	From	To
Weight in kg	Dose (mg/day)	Dose (mg/day)
20	600	900
25	900	1200
30	900	1200
35	900	1500
40	900	1500
45	1200	1500
50	1200	1800
55	1200	1800
60	1200	2100
65	1200	2100
70	1500	2100

2.7 Dosage Modification for Patients with Renal Impairment

In patients with impaired renal function (creatinine clearance <30 mL/min) initiate oxcarbazepine tablets at one-half the usual starting dose (300 mg/day, given twice-a-day) and increase slowly to achieve the desired clinical response [see Clinical Pharmacology (12.3 )].

2.8 Administration Information

Oxcarbazepine tablets can be taken with or without food [see Clinical Pharmacology (12.3)].  

Oxcarbazepine oral suspension and oxcarbazepine film-coated tablets may be interchanged at equal doses.

3 Dosage Forms And Strengths

Film-coated Tablets:

• 150 mg: yellow, oval, film-coated tablets, engraved and scored 'OXC 150' on one side, 'APO' on the other side.
• 300 mg: yellow, oval, film-coated tablets, engraved and scored 'OXC 300' on one side, 'APO' on the other side.
• 600 mg: yellow, oval, film-coated tablets, engraved and scored 'OXC 600' on one side and 'APO' on the other side.

• Film-coated tablets: 150 mg, 300 mg and 600 mg (3)

4 Contraindications

Oxcarbazepine tablets are contraindicated in patients with a known hypersensitivity to oxcarbazepine or to any of its components, or to eslicarbazepine acetate [see Warnings and Precautions (5.2, 5.3)].


Known hypersensitivity to oxcarbazepine or to any of its components, or to eslicarbazepine acetate (4, 5.2)

5 Warnings And Precautions

• Hyponatremia: Monitor serum sodium levels (5.1)
• Cross Hypersensitivity Reaction to Carbamazepine: Discontinue immediately if hypersensitivity occurs (5.3)
• Serious Dermatological Reactions: If occurs consider discontinuation (5.4)
• Suicidal Behavior and Ideation: Monitor for suicidal thoughts/ behavior (5.5)
• Withdrawal of AEDs: Withdraw oxcarbazepine tablets gradually (5.6)
• Cognitive/Neuropsychiatric Adverse Reactions: May cause cognitive dysfunction, somnolence, coordination abnormalities. Use caution when operating machinery (5.7)
• Drug Reaction with Eosinophilia and Systemic Symptoms (DRESS)/Multi-Organ Hypersensitivity: Monitor and discontinue if another cause cannot be established (5.8)
• Hematologic Events: Consider discontinuing (5.9)
• Seizure Control During Pregnancy: Active metabolite may decrease (5.10)
• Risk of Seizure Aggravation: Discontinue if occurs. (5.11)

5.1 Hyponatremia

Clinically significant hyponatremia (sodium <125 mmol/L) can develop during oxcarbazepine use. In the 14 controlled epilepsy studies 2.5% of oxcarbazepine-treated patients (38/1,524) had a sodium of less than 125 mmol/L at some point during treatment, compared to no such patients assigned placebo or active control (carbamazepine and phenobarbital for adjunctive and monotherapy substitution studies, and phenytoin and valproate for the monotherapy initiation studies). Clinically significant hyponatremia generally occurred during the first three months of treatment with oxcarbazepine, although there were patients who first developed a serum sodium <125 mmol/L more than one year after initiation of therapy. Most patients who developed hyponatremia were asymptomatic but patients in the clinical trials were frequently monitored and some had their oxcarbazepine dose reduced, discontinued, or had their fluid intake restricted for hyponatremia. Whether or not these maneuvers prevented the occurrence of more severe events is unknown. Cases of symptomatic hyponatremia and syndrome of inappropriate antidiuretic hormone secretion (SIADH) have been reported during postmarketing use. In clinical trials, patients whose treatment with oxcarbazepine was discontinued due to hyponatremia generally experienced normalization of serum sodium within a few days without additional treatment.

Measurement of serum sodium levels should be considered for patients during maintenance treatment with oxcarbazepine, particularly if the patient is receiving other medications known to decrease serum sodium levels (e.g., drugs associated with inappropriate ADH secretion) or if symptoms possibly indicating hyponatremia develop (e.g., nausea, malaise, headache, lethargy, confusion, obtundation, or increase in seizure frequency or severity).

5.2 Anaphylactic Reactions and Angioedema

Rare cases of anaphylaxis and angioedema involving the larynx, glottis, lips and eyelids have been reported in patients after taking the first or subsequent doses of oxcarbazepine. Angioedema associated with laryngeal edema can be fatal. If a patient develops any of these reactions after treatment with oxcarbazepine, the drug should be discontinued and an alternative treatment started. These patients should not be rechallenged with the drug [see Warnings and Precautions (5.3)].

5.3 Cross Hypersensitivity Reaction to Carbamazepine

Approximately 25% to 30% of patients who have had hypersensitivity reactions to carbamazepine will experience hypersensitivity reactions with oxcarbazepine. For this reason patients should be specifically questioned about any prior experience with carbamazepine, and patients with a history of hypersensitivity reactions to carbamazepine should ordinarily be treated with oxcarbazepine only if the potential benefit justifies the potential risk. If signs or symptoms of hypersensitivity develop, oxcarbazepine should be discontinued immediately [see Warnings and Precautions (5.2, 5.8)].

5.4 Serious Dermatological Reactions

Serious dermatological reactions, including Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN), have been reported in both children and adults in association with oxcarbazepine use. Such serious skin reactions may be life threatening, and some patients have required hospitalization with very rare reports of fatal outcome. The median time of onset for reported cases was 19 days after treatment initiation. Recurrence of the serious skin reactions following rechallenge with oxcarbazepine has also been reported.

The reporting rate of TEN and SJS associated with oxcarbazepine use, which is generally accepted to be an underestimate due to underreporting, exceeds the background incidence rate estimates by a factor of 3- to 10-fold. Estimates of the background incidence rate for these serious skin reactions in the general population range between 0.5 to 6 cases per million-person years. Therefore, if a patient develops a skin reaction while taking oxcarbazepine, consideration should be given to discontinuing oxcarbazepine use and prescribing another antiepileptic medication.

Association with HLA-B*1502

Patients carrying the HLA-B*1502 allele may be at increased risk for SJS/TEN with oxcarbazepine treatment.

Human Leukocyte Antigen (HLA) allele B*1502 increases the risk for developing SJS/TEN in patients treated with carbamazepine. The chemical structure of oxcarbazepine is similar to that of carbamazepine. Available clinical evidence, and data from nonclinical studies showing a direct interaction between oxcarbazepine and HLA-B*1502 protein, suggest that the HLA-B*1502 allele may also increase the risk for SJS/TEN with oxcarbazepine.

The frequency of HLA-B*1502 allele ranges from 2 to 12% in Han Chinese populations, is about 8% in Thai populations, and above 15% in the Philippines and in some Malaysian populations. Allele frequencies up to about 2% and 6% have been reported in Korea and India, respectively. The frequency of the HLA-B*1502 allele is negligible in people from European descent, several African populations, indigenous peoples of the Americas, Hispanic populations, and in Japanese (< 1%).

Testing for the presence of the HLA-B*1502 allele should be considered in patients with ancestry in genetically at-risk populations, prior to initiating treatment with oxcarbazepine. The use of oxcarbazepine should be avoided in patients positive for HLA-B*1502 unless the benefits clearly outweigh the risks. Consideration should also be given to avoid the use of other drugs associated with SJS/TEN in HLA-B*1502 positive patients, when alternative therapies are otherwise equally acceptable. Screening is not generally recommended in patients from populations in which the prevalence of HLA­B*1502 is low, or in current oxcarbazepine users, as the risk of SJS/TEN is largely confined to the first few months of therapy, regardless of HLA B*1502 status.

The use of HLA-B*1502 genotyping has important limitations and must never substitute for appropriate clinical vigilance and patient management. The role of other possible factors in the development of, and morbidity from, SJS/TEN, such as antiepileptic drug (AED) dose, compliance, concomitant medications, comorbidities, and the level of dermatologic monitoring have not been well characterized.

5.5 Suicidal Behavior and Ideation

Antiepileptic drugs (AEDs), including oxcarbazepine, increase the risk of suicidal thoughts or behavior in patients taking these drugs for any indication. Patients treated with any AED for any indication should be monitored for the emergence or worsening of depression, suicidal thoughts or behavior, and/or any unusual changes in mood or behavior. 

Pooled analyses of 199 placebo-controlled clinical trials (mono- and adjunctive therapy) of 11 different AEDs showed that patients randomized to one of the AEDs had approximately twice the risk (adjusted Relative Risk 1.8, 95% CI:1.2, 2.7) of suicidal thinking or behavior compared to patients randomized to placebo. In these trials, which had a median treatment duration of 12 weeks, the estimated incidence rate of suicidal behavior or ideation among 27,863 AED-treated patients was 0.43%, compared to 0.24% among 16,029 placebo-treated patients, representing an increase of approximately one case of suicidal thinking or behavior for every 530 patients treated. There were four suicides in drug-treated patients in the trials and none in placebo-treated patients, but the number is too small to allow any conclusion about drug effect on suicide.

The increased risk of suicidal thoughts or behavior with AEDs was observed as early as one week after starting drug treatment with AEDs and persisted for the duration of treatment assessed. Because most trials included in the analysis did not extend beyond 24 weeks, the risk of suicidal thoughts or behavior beyond 24 weeks could not be assessed.

The risk of suicidal thoughts or behavior was generally consistent among drugs in the data analyzed. The finding of increased risk with AEDs of varying mechanisms of action and across a range of indications suggests that the risk applies to all AEDs used for any indication. The risk did not vary substantially by age (5 to 100 years) in the clinical trials analyzed. Table 2 shows absolute and relative risk by indication for all evaluated AEDs.

Table 2: Risk by Indication for Antiepileptic Drugs in the Pooled Analysis

Indication	Placebo Patients with Events Per 1,000 Patients	Drug Patients with Events Per 1,000 Patients	Relative Risk: Incidence of Events in Drug Patients/Incidence in Placebo Patients	Risk Difference: Additional Drug Patients with Events Per 1,000 Patients
Epilepsy	1.0	3.4	3.5	2.4
Psychiatric	5.7	8.5	1.5	2.9
Other	1.0	1.8	1.9	0.9
Total	2.4	4.3	1.8	1.9

The relative risk for suicidal thoughts or behavior was higher in clinical trials for epilepsy than in clinical trials for psychiatric or other conditions, but the absolute risk differences were similar for the epilepsy and psychiatric indications.

Anyone considering prescribing oxcarbazepine or any other AED must balance the risk of suicidal thoughts or behavior with the risk of untreated illness. Epilepsy and many other illnesses for which AEDs are prescribed are themselves associated with morbidity and mortality and an increased risk of suicidal thoughts and behavior. Should suicidal thoughts and behavior emerge during treatment, the prescriber needs to consider whether the emergence of these symptoms in any given patient may be related to the illness being treated. 

Patients, their caregivers, and families should be informed that AEDs increase the risk of suicidal thoughts and behavior and should be advised of the need to be alert for the emergence or worsening of the signs and symptoms of depression, any unusual changes in mood or behavior, or the emergence of suicidal thoughts, behavior, or thoughts about self-harm. Behaviors of concern should be reported immediately to healthcare providers.

5.6 Withdrawal of AEDs

As with most antiepileptic drugs, oxcarbazepine should generally be withdrawn gradually because of the risk of increased seizure frequency and status epilepticus [see Dosage and Administration (2.4) and Clinical Studies (14)]. But if withdrawal is needed because of a serious adverse event, rapid discontinuation can be considered.

5.7 Cognitive/Neuropsychiatric Adverse Reactions

Use of oxcarbazepine has been associated with central nervous system-related adverse reactions. The most significant of these can be classified into three general categories: 1) cognitive symptoms including psychomotor slowing, difficulty with concentration, and speech or language problems, 2) somnolence or fatigue, and 3) coordination abnormalities, including ataxia and gait disturbances.

Patients should be monitored for these signs and symptoms and advised not to drive or operate machinery until they have gained sufficient experience on oxcarbazepine to gauge whether it adversely affects their ability to drive or operate machinery.

Adult Patients

In one large, fixed-dose study, oxcarbazepine was added to existing AED therapy (up to three concomitant AEDs). By protocol, the dosage of the concomitant AEDs could not be reduced as oxcarbazepine was added, reduction in oxcarbazepine dosage was not allowed if intolerance developed, and patients were discontinued if unable to tolerate their highest target maintenance doses. In this trial, 65% of patients were discontinued because they could not tolerate the 2400 mg/day dose of oxcarbazepine on top of existing AEDs. The adverse events seen in this study were primarily CNS related and the risk for discontinuation was dose related.

In this trial, 7.1% of oxcarbazepine-treated patients and 4% of placebo-treated patients experienced a cognitive adverse reaction. The risk of discontinuation for these events was about 6.5 times greater on oxcarbazepine than on placebo. In addition, 26% of oxcarbazepine-treated patients and 12% of placebo-treated patients experienced somnolence. The risk of discontinuation for somnolence was about 10 times greater on oxcarbazepine than on placebo. Finally, 28.7% of oxcarbazepine-treated patients and 6.4% of placebo-treated patients experienced ataxia or gait disturbances. The risk for discontinuation for these events was about seven times greater on oxcarbazepine than on placebo.

In a single placebo-controlled monotherapy trial evaluating 2400 mg/day of oxcarbazepine, no patients in either treatment group discontinued double-blind treatment because of cognitive adverse events, somnolence, ataxia, or gait disturbance.

In the two dose-controlled conversion to monotherapy trials comparing 2400 mg/day and 300 mg/day oxcarbazepine, 1.1% of patients in the 2400 mg/day group discontinued double-blind treatment because of somnolence or cognitive adverse reactions compared to 0% in the 300 mg/day group. In these trials, no patients discontinued because of ataxia or gait disturbances in either treatment group.

Pediatric Patients

A study was conducted in pediatric patients (3 to 17 years old) with inadequately controlled partial-onset seizures in which oxcarbazepine was added to existing AED therapy (up to two concomitant AEDs). By protocol, the dosage of concomitant AEDs could not be reduced as oxcarbazepine was added. Oxcarbazepine was titrated to reach a target dose ranging from 30 mg/kg to 46 mg/kg (based on a patient’s body weight with fixed doses for predefined weight ranges).

Cognitive adverse events occurred in 5.8% of oxcarbazepine treated patients (the single most common event being concentration impairment, 4 of 138 patients) and in 3.1% of patients treated with placebo. In addition, 34.8% of oxcarbazepine-treated patients and 14.0% of placebo-treated patients experienced somnolence. (No patient discontinued due to a cognitive adverse reaction or somnolence.). Finally, 23.2% of oxcarbazepine-treated patients and 7.0% of placebo-treated patients experienced ataxia or gait disturbances. Two (1.4%) oxcarbazepine-treated patients and 1 (0.8%) placebo-treated patient discontinued due to ataxia or gait disturbances.

5.8 Drug Reaction with Eosinophilia and Systemic Symptoms (DRESS)/Multi-Organ Hypersensitivity

Drug Reaction with Eosinophilia and Systemic Symptoms (DRESS), also known as multi-organ hypersensitivity, has occurred with oxcarbazepine. Some of these events have been fatal or life-threatening. DRESS typically, although not exclusively, presents with fever, rash, lymphadenopathy and/or facial swelling, in association with other organ system involvement, such as hepatitis, nephritis, hematologic abnormalities, myocarditis, or myositis sometimes resembling an acute viral infection. Eosinophilia is often present. This disorder is variable in its expression, and other organ systems not noted here may be involved. It is important to note that early manifestations of hypersensitivity (e.g., fever, lymphadenopathy) may be present even though rash is not evident. If such signs or symptoms are present, the patient should be evaluated immediately. Oxcarbazepine should be discontinued if an alternative etiology for the signs or symptoms cannot be established.

5.9 Hematologic Events

Rare reports of pancytopenia, agranulocytosis, and leukopenia have been seen in patients treated with oxcarbazepine during postmarketing experience. Discontinuation of the drug should be considered if any evidence of these hematologic events develops.

5.10 Seizure Control During Pregnancy

Due to physiological changes during pregnancy, plasma levels of the active metabolite of oxcarbazepine, the 10-monohydroxy derivative (MHD), may gradually decrease throughout pregnancy. It is recommended that patients be monitored carefully during pregnancy. Close monitoring should continue through the postpartum period because MHD levels may return after delivery.

5.11 Risk of Seizure Aggravation

Exacerbation of or new onset primary generalized seizures has been reported with oxcarbazepine. The risk of aggravation of primary generalized seizures is seen especially in children but may also occur in adults. In case of seizure aggravation, oxcarbazepine should be discontinued.

6 Adverse Reactions

The following serious adverse reactions are described below and elsewhere in the labeling:

• Hyponatremia [see Warnings and Precautions (5.1)]
• Anaphylactic Reactions and Angioedema [see Warnings and Precautions (5.2)]
• Cross Hypersensitivity Reaction to Carbamazepine [see Warnings and Precautions (5.3)]
• Serious Dermatological Reactions [see Warnings and Precautions (5.4)]
• Suicidal Behavior and Ideation [see Warnings and Precautions (5.5)]
• Cognitive/Neuropsychiatric Adverse Reactions [see Warnings and Precautions (5.7)]
• Drug Reaction with Eosinophilia and Systemic Symptoms (DRESS)/Multi-Organ Hypersensitivity [see Warnings and Precautions (5.8)]
• Hematologic Events [see Warnings and Precautions (5.9)]

The most common (≥10% more than placebo for adjunctive or low dose for monotherapy) adverse reactions in adults and pediatrics were: dizziness, somnolence, diplopia, fatigue, nausea, vomiting, ataxia, abnormal vision, headache, nystagmus, tremor, and abnormal gait. (6.1)

To report SUSPECTED ADVERSE REACTIONS, contact Apotex Corp., at 1-800-706-5575 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch.

6.1 Clinical Trials Experience

Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in practice.

Most Common Adverse Reactions in All Clinical Studies

Adjunctive Therapy/Monotherapy in Adults Previously Treated with Other AEDs

The most common (≥10% more than placebo for adjunctive or low dose for monotherapy) adverse reactions with oxcarbazepine: dizziness, somnolence, diplopia, fatigue, nausea, vomiting, ataxia, abnormal vision, headache, nystagmus tremor, and abnormal gait.

Approximately 23% of these 1,537 adult patients discontinued treatment because of an adverse reaction. The adverse reactions most commonly associated with discontinuation were: dizziness (6.4%), diplopia (5.9%), ataxia (5.2%), vomiting (5.1%), nausea (4.9%), somnolence (3.8%), headache (2.9%), fatigue (2.1%), abnormal vision (2.1%), tremor (1.8%), abnormal gait (1.7%), rash (1.4%), hyponatremia (1.0%).   

Monotherapy in Adults Not Previously Treated with Other AEDs

The most common (≥5%) adverse reactions with oxcarbazepine in these patients were similar to those in previously treated patients.

Approximately 9% of these 295 adult patients discontinued treatment because of an adverse reaction. The adverse reactions most commonly associated with discontinuation were: dizziness (1.7%), nausea (1.7%), rash (1.7%), headache (1.4%).

Adjunctive Therapy/Monotherapy in Pediatric Patients 4 Years Old and Above Previously Treated with Other AEDs

The most common (≥5%) adverse reactions with oxcarbazepine in these patients were similar to those seen in adults.

Approximately 11% of these 456 pediatric patients discontinued treatment because of an adverse reaction. The adverse reactions most commonly associated with discontinuation were: somnolence (2.4%), vomiting (2.0%), ataxia (1.8%), diplopia (1.3%), dizziness (1.3%), fatigue (1.1%), nystagmus (1.1%).

Monotherapy in Pediatric Patients 4 Years Old and Above Not Previously Treated with Other AEDs

The most common (≥5%) adverse reactions with oxcarbazepine in these patients were similar to those in adults.

Approximately 9.2% of 152 pediatric patients discontinued treatment because of an adverse reaction. The adverse reactions most commonly associated (≥1%) with discontinuation were rash (5.3%) and maculopapular rash (1.3%).

Adjunctive Therapy/Monotherapy in Pediatric Patients 1 Month to < 4 Years Old Previously Treated or Not Previously Treated with Other AEDs

The most common (≥5%) adverse reactions with oxcarbazepine in these patients were similar to those seen  in older children and adults except for infections and infestations which were more frequently seen in these younger children.

Approximately 11% of these 241 pediatric patients discontinued treatment because of an adverse reaction. The adverse reactions most commonly associated with discontinuation were: convulsions (3.7%), status epilepticus (1.2%), and ataxia (1.2%).

Controlled Clinical Studies of Adjunctive Therapy/Monotherapy in Adults Previously Treated with Other AEDs

Table 3 uls adverse reactions that occurred in at least 2% of adult patients with epilepsy, treated with oxcarbazepine or placebo as adjunctive treatment and were numerically more common in the patients treated with any dose of oxcarbazepine.

Table 4 uls adverse reactions in patients converted from other AEDs to either high dose oxcarbazepine (2400 mg/day) or low dose (300 mg/day) oxcarbazepine. Note that in some of these monotherapy studies patients who dropped out during a preliminary tolerability phase are not included in the tables.
Table 3: Adverse Reactions in a Controlled Clinical Study of Adjunctive Therapy with Oxcarbazepine in Adults

	Oxcarbazepine Dosage (mg/day)
Body System/ Adverse Reaction	Oxcarbazepine 600 N=163 %	Oxcarbazepine 1200 N=171  %	Oxcarbazepine 2400 N=126 %	Placebo N=166 %
Body as a Whole
Fatigue	15	12	15	7
Asthenia	6	3	6	5
Leg Edema	2	1	2	1
Increased Weight	1	2	2	1
Feeling Abnormal	0	1	2	0
Cardiovascular System
Hypotension	0	1	2	0
Digestive System
Nausea	15	25	29	10
Vomiting	13	25	36	5
Abdominal Pain	10	13	11	5
Diarrhea	5	6	7	6
Dyspepsia	5	5	6	2
Constipation	2	2	6	4
Gastritis	2	1	2	1
Metabolic and Nutritional Disorders
Hyponatremia	3	1	2	1
Musculoskeletal System
Muscle Weakness	1	2	2	0
Sprains and Strains	0	2	2	1
Nervous System
Headache	32	28	26	23
Dizziness	26	32	49	13
Somnolence	20	28	36	12
Ataxia	9	17	31	5
Nystagmus	7	20	26	5
Abnormal Gait	5	10	17	1
Insomnia	4	2	3	1
Tremor	3	8	16	5
Nervousness	2	4	2	1
Agitation	1	1	2	1
Abnormal Coordination	1	3	2	1
Abnormal EEG	0	0	2	0
Speech Disorder	1	1	3	0
Confusion	1	1	2	1
Cranial Injury NOS	1	0	2	1
Dysmetria	1	2	3	0
Abnormal Thinking	0	2	4	0
Respiratory System
Rhinitis	2	4	5	4
Skin and Appendages
Acne	1	2	2	0
Special Senses
Diplopia	14	30	40	5
Vertigo	6	12	15	2
Abnormal Vision	6	14	13	4
Abnormal Accommodation	0	0	2	0

Table 4: Adverse Reactions in Controlled Clinical Studies of Monotherapy with Oxcarbazepine in Adults Previously Treated with Other AEDs

Body System/ Adverse Reaction	Oxcarbazepine 2400 mg/day N=86 %		Oxcarbazepine 300 mg/day N=86 %
Body as a Whole
Fatigue	21		5
Fever	3		0
Allergy	2		0
Generalized Edema	2		1
Chest Pain	2		0
Digestive System
Nausea	22		7
Vomiting	15		5
Diarrhea	7		5
Dyspepsia	6		1
Anorexia	5		3
Abdominal Pain	5		3
Dry Mouth	3		0
Hemorrhage Rectum	2		0
Toothache	2		1
Hemic and Lymphatic System
Lymphadenopathy	2		0
Infections and Infestations
Viral Infection	7		5
Infection	2		0
Metabolic and Nutritional Disorders
Hyponatremia	5		0
Thirst	2		0
Nervous System
Headache	31		15
Dizziness	28		8
Somnolence	19		5
Anxiety	7		5
Ataxia	7		1
Confusion	7		0
Nervousness	7		0
Insomnia	6		3
Tremor	6		3
Amnesia	5		1
Aggravated Convulsions	5		2
Emotional Lability	3		2
Hypoesthesia	3		1
Abnormal Coordination	2		1
Nystagmus	2		0
Speech Disorder	2		0
Respiratory System
Upper Respiratory Tract Infection	10		5
Coughing	5		0
Bronchitis	3		0
Pharyngitis	3		0
Skin and Appendages
Hot Flushes	2		1
Purpura	2		0
Special Senses
Abnormal Vision	14		2
Diplopia	12		1
Taste Perversion	5		0
Vertigo	3		0
Earache	2		1
Ear Infection NOS	2		0
Urogenital and Reproductive System
Urinary Tract Infection	5		1
Micturition Frequency	2		1
Vaginitis	2		0

Controlled Clinical Study of Monotherapy in Adults Not Previously Treated with Other AEDs

Table 5 uls adverse reactions in a controlled clinical study of monotherapy in adults not previously treated with other AEDs that occurred in at least 2% of adult patients with epilepsy treated with oxcarbazepine or placebo and were numerically more common in the patients treated with oxcarbazepine.

Table 5: Adverse Reactions in a Controlled Clinical Study of Monotherapy with Oxcarbazepine in Adults Not Previously Treated with Other AEDs

Body System/ Adverse Reaction	Oxcarbazepine N=55 %	Placebo N=49 %
Body as a Whole
Falling Down NOS	4	0
Digestive System
Nausea	16	12
Diarrhea	7	2
Vomiting	7	6
Constipation	5	0
Dyspepsia	5	4
Musculoskeletal System
Back Pain	4	2
Nervous System
Dizziness	22	6
Headache	13	10
Ataxia	5	0
Nervousness	5	2
Amnesia	4	2
Abnormal Coordination	4	2
Tremor	4	0
Respiratory System
Upper Respiratory Tract Infection	7	0
Epistaxis	4	0
Infection Chest	4	0
Sinusitis	4	2
Skin and Appendages
Rash	4	2
Special Senses
Vision Abnormal	4	0

Controlled Clinical Studies of Adjunctive Therapy/Monotherapy in Pediatric Patients Previously Treated with Other AEDs

Table 6 uls adverse reactions that occurred in at least 2% of pediatric patients with epilepsy treated with oxcarbazepine or placebo as adjunctive treatment and were numerically more common in the patients treated with oxcarbazepine.

Table 6: Adverse Reactions in Controlled Clinical Studies of Adjunctive Therapy/Monotherapy with Oxcarbazepine in Pediatric Patients Previously Treated with Other AEDs

Body System/ Adverse Reactions	Oxcarbazepine   N=171 %	Placebo N=139 %
Body as a Whole
Fatigue	13	9
Allergy	2	0
Asthenia	2	1
Digestive System
Vomiting	33	14
Nausea	19	5
Constipation	4	1
Dyspepsia	2	0
Nervous System
Headache	31	19
Somnolence	31	13
Dizziness	28	8
Ataxia	13	4
Nystagmus	9	1
Emotional Lability	8	4
Abnormal Gait	8	3
Tremor	6	4
Speech Disorder	3	1
Impaired Concentration	2	1
Convulsions	2	1
Involuntary Muscle Contractions	2	1
Respiratory System
Rhinitis	10	9
Pneumonia	2	1
Skin and Appendages
Bruising	4	2
Increased Sweating	3	0
Special Senses
Diplopia	17	1
Abnormal Vision	13	1
Vertigo	2	0

Other Events Observed in Association with the Administration of Oxcarbazepine

In the paragraphs that follow, the adverse reactions, other than those in the preceding tables or text, that occurred in a total of 565 children and 1,574 adults exposed to oxcarbazepine and that are reasonably likely to be related to drug use are presented. Events common in the population, events reflecting chronic illness and events likely to reflect concomitant illness are omitted particularly if minor. They are uled in order of decreasing frequency. Because the reports cite events observed in open label and uncontrolled trials, the role of oxcarbazepine in their causation cannot be reliably determined.

Body as a Whole Fever, malaise, pain chest precordial, rigors, weight decrease.

Cardiovascular System Bradycardia, cardiac failure, cerebral hemorrhage, hypertension, hypotension postural, palpitation, syncope, tachycardia.

Digestive System Appetite increased, blood in stool, cholelithiasis, colitis, duodenal ulcer, dysphagia, enteritis, eructation, esophagitis, flatulence, gastric ulcer, gingival bleeding, gum hyperplasia, hematemesis, hemorrhage rectum, hemorrhoids, hiccup, mouth dry, pain biliary, pain right hypochondrium, retching, sialoadenitis, stomatitis, stomatitis ulcerative.

Hematologic and Lymphatic System Thrombocytopenia.

Laboratory Abnormality Gamma-GT increased, hyperglycemia, hypocalcemia, hypoglycemia, hypokalemia, liver enzymes elevated, serum transaminase increased.

Musculoskeletal System Hypertonia muscle.

Nervous System Aggressive reaction, amnesia, anguish, anxiety, apathy, aphasia, aura, convulsions aggravated, delirium, delusion, depressed level of consciousness, dysphonia, dystonia, emotional lability, euphoria, extrapyramidal disorder, feeling drunk, hemiplegia, hyperkinesia, hyperreflexia, hypoesthesia, hypokinesia, hyporeflexia, hypotonia, hysteria, libido decreased, libido increased, manic reaction, migraine, muscle contractions involuntary, nervousness, neuralgia, oculogyric crisis, panic disorder, paralysis, paroniria, personality disorder, psychosis, ptosis, stupor, tetany.

Respiratory System Asthma, dyspnea, epistaxis, laryngismus, pleurisy.

Skin and Appendages Acne, alopecia, angioedema, bruising, dermatitis contact, eczema, facial rash, flushing, folliculitis, heat rash, hot flushes, photosensitivity reaction, pruritus genital, psoriasis, purpura, rash erythematous, rash maculopapular, vitiligo, urticaria.

Special Senses Accommodation abnormal, cataract, conjunctival hemorrhage, edema eye, hemianopia, mydriasis, otitis externa, photophobia, scotoma, taste perversion, tinnitus, xerophthalmia.

Surgical and Medical Procedures Procedure dental oral, procedure female reproductive, procedure musculoskeletal, procedure skin.

Urogenital and Reproductive System Dysuria, hematuria, intermenstrual bleeding, leukorrhea, menorrhagia, micturition frequency, pain renal, pain urinary tract, polyuria, priapism, renal calculus.

Other Systemic lupus erythematosus.

Laboratory Tests

Serum sodium levels below 125 mmol/L have been observed in patients treated with oxcarbazepine [see Warnings and Precautions (5.1)]. Experience from clinical trials indicates that serum sodium levels return toward normal when the oxcarbazepine tablet dosage is reduced or discontinued, or when the patient was treated conservatively (e.g., fluid restriction).  

Laboratory data from clinical trials suggest that oxcarbazepine use was associated with decreases in T₄, without changes in T₃ or TSH.

6.2 Postmarketing Experience

The following adverse reactions have been identified during postapproval use of oxcarbazepine. 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.

Body as a Whole: multi-organ hypersensitivity disorders characterized by features such as rash, fever, lymphadenopathy, abnormal liver function tests, eosinophilia and arthralgia [see Warnings and Precautions (5.8)]

Cardiovascular System: atrioventricular block

Immune System Disorders: anaphylaxis [see Warnings and Precautions (5.2)]

Digestive System: pancreatitis and/or lipase and/or amylase increase

Hematologic and Lymphatic Systems: aplastic anemia [see Warnings and Precautions (5.9)]

Metabolism and Nutrition Disorders: hypothyroidism and syndrome of inappropriate antidiuretic hormone secretion (SIADH)

Skin and Subcutaneous Tissue Disorders: erythema multiforme, Stevens-Johnson syndrome, toxic epidermal necrolysis [see Warnings and Precautions (5.4)], Acute Generalized Exanthematous Pustulosis (AGEP)

Musculoskeletal, connective tissue and bone disorders: There have been reports of decreased bone mineral density, osteoporosis and fractures in patients on long-term therapy with oxcarbazepine.

Injury, Poisoning, and Procedural Complications: fall  

Nervous System Disorders: dysarthria