Oxtellar Xr
(oxcarbazepine)Dosage & Administration
By using PrescriberAI, you agree to the AI Terms of Use.
Oxtellar XR Prescribing Information
Oxtellar XR is indicated for the treatment of partial-onset seizures in patients 6 years of age and older.
Important Administration Instructions
Administer Oxtellar XR as a single daily dose taken on an empty stomach (at least 1 hour before or at least 2 hours after meals) [see Clinical Pharmacology (12.3)] . If Oxtellar XR is taken with food, adverse reactions are more likely to occur because of increased peak levels [see Clinical Pharmacology (12.3)].
Swallow Oxtellar XR tablets whole. Do not cut, crush, or chew the tablets. For ease of swallowing in pediatric patients or patients with difficulty swallowing, achieve daily dosages with multiples of appropriate lower strength tablets (e.g., 150 mg tablets).
General Dosing Recommendations
Monotherapy or Adjunctive Therapy
Adult Patients
Initiate treatment at a dosage of 600 mg/day given orally once daily for one week. Subsequent dosage increases can be made at weekly intervals in 600 mg/day increments to achieve the recommended daily dosage.
The recommended daily dosage of Oxtellar XR is 1200 mg to 2400 mg/day, given once daily. The dosage of 2400 mg/day showed slightly greater efficacy than 1200 mg/day, but was associated with an increase in adverse reactions [see Adverse Reactions (6.1)and Clinical Studies (14.1)].
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)].
Pediatric Patients (6 to Less than 17 Years of Age)
In pediatric patients 6 to less than 17 years of age, initiate treatment at a daily dosage of 8 mg/kg to 10 mg/kg orally once daily, not to exceed 600 mg per day in the first week.
Subsequent dosage increases can be made at weekly intervals in 8 mg/kg to 10 mg/kg increments once daily, not to exceed 600 mg, to achieve the target daily dosage. The target maintenance dosage, achieved over two to three weeks, is displayed in Table 1.
| Weight | Target Daily Dosage |
|---|---|
| 20 kg to 29 kg | 900 mg/day |
| 29.1 kg to 39 kg | 1200 mg/day |
| Greater than 39 kg | 1800 mg/day |
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))].
Dosage Modifications in Adult Patients with Renal Impairment
In adult patients with severe renal impairment (creatinine clearance less than 30 mL/minute), initiate Oxtellar XR at one-half the usual starting dosage (300 mg/day). Subsequent dosage increases can be made at weekly intervals in increments of 300 mg to 450 mg/day to achieve the desired clinical response [see Use in Specific Populations (8.6)].
Dosage Modifications in Geriatric Patients
In geriatric patients, consider starting at a lower dosage (300 mg or 450 mg/day). Subsequent dosage increases can be made at weekly intervals in increments of 300 mg to 450 mg/day to achieve the desired clinical effect [see Use in Specific Populations (8.5)].
Dosage Modification with Concomitant Use of Strong CYP3A4 Enzyme Inducers or UGT Enzyme Inducers
Strong CYP3A4 inducers, including enzyme-inducing antiepileptic drugs such as carbamazepine, phenobarbital, and phenytoin, and UGT inducers (e.g., rifampin) decrease exposure to 10-monohydroxy derivative (MHD), the active metabolite [see Drug Interactions (7.2)and Clinical Pharmacology (12.3)] . Dosage adjustment of Oxtellar XR may be required after initiation, dosage modification, or discontinuation of such inducers. Dosage increases of Oxtellar XR may be necessary with concomitant use. Consider initiating at 900 mg once daily for adults and 12 to 15 mg/kg orally once daily (not to exceed 900 mg per day in the first week) in pediatric patients.
Withdrawal of AEDs
As with most antiepileptic drugs, Oxtellar XR should be withdrawn gradually because of the risk of increased seizure frequency and status epilepticus [see Warnings and Precautions (5.6)].
Conversion from Immediate-Release Oxcarbazepine to Oxtellar XR
In conversion of oxcarbazepine immediate-release to Oxtellar XR, higher dosages of Oxtellar XR may be necessary [see Clinical Pharmacology (12.3)].
Extended-release tablets:
- 150 mg: yellow modified-oval shaped with "150" printed on one side
- 300 mg: brown modified-oval shaped with "300" printed on one side
- 600 mg: brownish red modified-oval shaped with "600" printed on one side
Pregnancy
Pregnancy Exposure Registry
There is a pregnancy exposure registry that monitors pregnancy outcomes in women exposed to AEDs, such as Oxtellar XR, during pregnancy. Encourage women who are taking Oxtellar XR during pregnancy to enroll in the North American Antiepileptic Drug (NAAED Pregnancy Registry) by calling 1-888-233-2334 or visiting http://www.aedpregnancyregistry.org/.
Risk Summary
There are no adequate data on the developmental risks associated with the use of Oxtellar XR in pregnant women; however, Oxtellar XR is closely related structurally to carbamazepine, which is considered to be teratogenic in humans. Data on a limited number of pregnancies from pregnancy registries suggest that oxcarbazepine monotherapy use is associated with congenital malformations (e.g., craniofacial defects such as oral clefts, and cardiac malformations such as ventricular septal defects). Increased incidences of fetal structural abnormalities and other manifestations of developmental toxicity (embryolethality, growth retardation) were observed in the offspring of animals treated with either oxcarbazepine or its active 10-hydroxy metabolite (MHD) during pregnancy at doses similar to the maximum recommended human dose (MRHD).
In the U.S. general population, the estimated background risk of major birth defects and miscarriage in clinically recognized pregnancies is 2-4% and 15-20%, respectively. The background risk of major birth defects and miscarriage for the indicated population is unknown.
Clinical Considerations
An increase in seizure frequency may occur during pregnancy because of altered levels of the active metabolite of oxcarbazepine. Monitor patients carefully during pregnancy and through the postpartum period [see Warnings and Precautions (5.9)]
Data
Human Data
Data from published registries have reported craniofacial defects such as oral clefts and cardiac malformations such as ventricular septal defects in children with prenatal oxcarbazepine exposure.
Animal Data
When pregnant rats were given oxcarbazepine (30, 300, or 1000 mg/kg/day) orally throughout the period of organogenesis, increased incidences of fetal malformations (craniofacial, cardiovascular, and skeletal) and variations were observed at the intermediate and high doses (approximately 1.2 and 4 times, respectively, the MRHD on a mg/m 2basis). Increased embryofetal death and decreased fetal body weights were seen at the high dose. Doses ≥ 300 mg/kg were also maternally toxic (decreased body weight gain, clinical signs), but there is no evidence to suggest that teratogenicity was secondary to the maternal effects.
In a study in which pregnant rabbits were orally administered MHD (20, 100, or 200 mg/kg/day) during organogenesis, embryofetal mortality was increased at the highest dose (1.5 times the MRHD on a mg/m 2basis). This dose produced only minimal maternal toxicity.
In a study in which female rats were dosed orally with oxcarbazepine (25, 50, or 150 mg/kg/day) during the latter part of gestation and throughout the lactation period, a persistent reduction in body weights and altered behavior (decreased activity) were observed in offspring exposed to the highest dose (0.6 times the MRHD on a mg/m 2basis). Oral administration of MHD (25, 75, or 250 mg/kg/day) to rats during gestation and lactation resulted in a persistent reduction in offspring weights at the highest dose (equivalent to the MRHD on a mg/m 2basis).
Lactation
Risk Summary
Oxcarbazepine and its active metabolite (MHD) are present in human milk after oxcarbazepine administration. The effects of oxcarbazepine and its active metabolite (MHD) on the breastfed infant or on milk production are unknown. The developmental and health benefits of breastfeeding should be considered along with the mother's clinical need for Oxtellar XR and any potential adverse effects on the breastfed infant from Oxtellar XR or from the underlying maternal condition.
Females and Males of Reproductive Potential
Contraception
Use of Oxtellar XR with hormonal contraceptives containing ethinylestradiol or levonorgestrel is associated with decreased plasma concentrations of these hormones and may result in a failure of the therapeutic effect of the oral contraceptive drug. Advise women of reproductive potential taking Oxtellar XR who are using a contraceptive containing ethinylestradiol or levonorgestrel to use additional or alternative non-hormonal birth control [see Drug Interactions (7.3)and Clinical Pharmacology (12.3)].
Pediatric Use
The safety and effectiveness of Oxtellar XR in pediatric patients 6 years of age and older for the treatment of partial-onset seizures is supported by:
- An adequate and well-controlled safety and efficacy study of Oxtellar XR in adults that included pharmacokinetic sampling [see Clinical Studies (14.1)],
- A pharmacokinetic study of Oxtellar XR in pediatric patients, which included patients 6 to less than 17 years of age [see Clinical Pharmacology (12.3)],
- Safety and efficacy studies with the immediate-release formulation in adults and pediatric patients [see Clinical Studies (14.2)and Adverse Reactions (6.1)] .
Oxtellar XR ®is not approved for pediatric patients less than 6 years of age because the size of the tablets are inappropriate for younger children.
Geriatric Use
Following administration of single (300 mg) and multiple (600 mg/day) doses of immediate-release oxcarbazepine to elderly volunteers (60-82 years of age), the maximum plasma concentrations and AUC values of MHD were 30%-60% higher than in younger volunteers (18-32 years of age). Comparisons of creatinine clearance in young and elderly volunteers indicate that the difference was due to age-related reductions in creatinine clearance. Consider starting at a lower dosage and lower titration [see Dosage and Administration (2.4)] . Close monitoring of sodium levels is required in elderly patients at risk for hyponatremia [see Warnings and Precautions (5.1)].
Renal Impairment
There is a linear correlation between creatinine clearance and the renal clearance of MHD [see Clinical Pharmacology (12.3)and Dosage and Administration (2.3)].
The pharmacokinetics of Oxtellar XR has not been evaluated in patients with renal impairment. In patients with severe renal impairment (creatinine clearance <30 mL/min) given immediate-release oxcarbazepine, the elimination half-life of MHD was prolonged with a corresponding two-fold increase in AUC [see Clinical Pharmacology (12.3)]. In these patients initiate Oxtellar XR at a lower starting dosage and increase, if necessary, at a slower than usual rate until the desired clinical response is achieved [see Dosage and Administration (2.3)] .
In patients with end-stage renal disease on dialysis, it is recommended that immediate-release oxcarbazepine be used instead of Oxtellar XR.
Hepatic Impairment
The pharmacokinetics of oxcarbazepine and MHD has not been evaluated in severe hepatic impairment, and therefore is not recommended in these patients [see Clinical Pharmacology (12.3)].
Oxtellar XR is contraindicated in patients with a known hypersensitivity to oxcarbazepine, to any of the components of Oxtellar XR, or to eslicarbazepine acetate. Reactions have included anaphylaxis and angioedema [see Warnings and Precautions (5.2, 5.3)].
Hyponatremia
Clinically significant hyponatremia (sodium <125 mmol/L) may develop during Oxtellar XR use. Serum sodium levels less than 125 mmol/L have occurred in immediate-release oxcarbazepine-treated patients generally in the first three months of treatment. However, clinically significant hyponatremia may develop more than a year after initiating therapy.
Most immediate-release oxcarbazepine-treated patients who developed hyponatremia were asymptomatic in clinical trials. However, some of these patients had their dosage reduced, discontinued, or had their fluid intake restricted for hyponatremia. Serum sodium levels returned toward normal when the dosage was reduced or discontinued, or when the patient was treated conservatively (e.g., fluid restriction). Cases of symptomatic hyponatremia and syndrome of inappropriate antidiuretic hormone secretion (SIADH) have been reported during post-marketing use of immediate-release oxcarbazepine.
Among treated patients in a controlled trial of adjunctive therapy with Oxtellar XR in 366 adults with complex partial seizures, 1 patient receiving 2400 mg experienced a severe reduction in serum sodium (117 mEq/L) requiring discontinuation from treatment, while 2 other patients receiving 1200 mg experienced serum sodium concentrations low enough (125 and 126 mEq/L) to require discontinuation from treatment. The overall incidence of clinically significant hyponatremia in patients treated with Oxtellar XR was 1.2%, although slight shifts in serum sodium concentrations from Normal to Low (<135 mEq/L) were observed for the 2400 mg (6.5%) and 1200 mg (9.8%) groups compared to placebo (1.7%).
Measure serum sodium concentrations if patients develop symptoms of hyponatremia (e.g., nausea, malaise, headache, lethargy, confusion, obtunded consciousness, or increase in seizure frequency or severity). Consider measurement of serum sodium concentrations during treatment with Oxtellar XR, particularly if the patient receives concomitant medications known to decrease serum sodium levels (for example, drugs associated with inappropriate ADH secretion).
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 immediate-release oxcarbazepine. Angioedema associated with laryngeal edema can be fatal. If a patient develops any of these reactions after treatment with Oxtellar XR, discontinue the drug and initiate an alternative treatment. Do not rechallenge these patients with Oxtellar XR.
Cross Hypersensitivity Reaction to Carbamazepine
Approximately 25% to 30% of patients who have had hypersensitivity reactions to carbamazepine will experience hypersensitivity reactions with Oxtellar XR. 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 Oxtellar XR only if the potential benefit justifies the potential risk. Discontinue Oxtellar XR immediately if signs or symptoms of hypersensitivity develop [see Warnings and Precautions (5.2, 5.7)].
Serious Dermatological Reactions
Serious dermatological reactions, including Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN), have occurred in both children and adults treated with immediate-release oxcarbazepine use. The median time of onset for reported cases was 19 days. Such serious skin reactions may be life threatening, and some patients have required hospitalization with very rare reports of fatal outcome. Recurrence of the serious skin reactions following rechallenge with immediate-release oxcarbazepine has also been reported.
The reporting rate of TEN and SJS associated with immediate-release 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 Oxtellar XR, consider discontinuing Oxtellar XR use and prescribing another AED.
Association with HLA-B*1502
Patients carrying the HLA-B*1502 allele may be at increased risk for SJS/TEN with Oxtellar XR treatment.
Human Leukocyte Antigen (HLA) allele B*1502 increases the risk for developing SJS/TEN in patients treated with carbamazepine. The chemical structures of immediate-release oxcarbazepine and Oxtellar XR are similar to that of carbamazepine. Available clinical evidence, and data from nonclinical studies showing a direct interaction between immediate-release oxcarbazepine and HLA-B*1502 protein, suggest that the HLA-B*1502 allele may also increase the risk for SJS/TEN with Oxtellar XR.
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 Oxtellar XR. The use of Oxtellar XR 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 HLA-B*1502 is low, or in current Oxtellar XR 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) dosage, compliance, concomitant medications, comorbidities, and the level of dermatologic monitoring have not been well characterized.
Suicidal Behavior and Ideation
Antiepileptic drugs (AEDs), including Oxtellar XR, increase the risk of suicidal thoughts or behavior in patients taking these drugs for any indication. Monitor patients treated with any AED for any indication 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 (5-100 years) in the clinical trials analyzed. Table 2 shows absolute and relative risk by indication for all evaluated AEDs.
| Indication | Placebo Patients with Events per 1000 Patients | Drug Patients with Events per 1000 Patients | Relative Risk: Incidence of Events in Drug Patients/Incidence in Placebo Patients | Risk Difference: Additional Drug Patients with Events per 1000 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 Oxtellar XR 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 Oxtellar XR treatment, the prescriber needs to consider whether the emergence of these symptoms in any given patient may be related to the illness being treated.
Withdrawal of AEDs
As with most AEDs, Oxtellar XR should be withdrawn gradually because of the risk of increased seizure frequency and status epilepticus. But if withdrawal is needed because of a serious adverse event, rapid discontinuation can be considered.
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 immediate-release 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 associated with other organ system involvement, such as hepatitis, nephritis, hematologic abnormalities, myocaraditis, 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 manifestatios of hypersensitivity (e.g., fever, lymphadenopathy) may be present even though rash is not evident. Oxtellar XR should be discontinued if an alternative etiology for the signs and symptoms cannot be established.
Hematologic Reactions
Rare reports of pancytopenia, agranulocytosis, and leukopenia have been seen in patients treated with immediate-release oxcarbazepine during post-marketing experience. Discontinuation of Oxtellar XR should be considered if any evidence of these hematologic reactions develops.
Risk of Seizures in the Pregnant Patient
Due to physiological changes during pregnancy, plasma concentrations of the active metabolite of oxcarbazepine, the 10-monohydroxy derivative (MHD), may gradually decrease throughout pregnancy. Monitor patients carefully during pregnancy and through the postpartum period because MHD concentrations may increase after delivery.
Risk of Seizure Aggravation
Exacerbation of or new onset primary generalized seizures has been reported with immediate-release 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, Oxtellar XR should be discontinued.