Rufinamide 100 Mg Oral Tablet

The recommended starting daily dose of rufinamide tablets in pediatric patients with Lennox-Gastaut Syndrome is approximately 10 mg/kg administered in two equally divided doses. The dose should be increased by approximately 10 mg/kg increments every other day until a maximum daily dose of 45 mg/kg, not to exceed 3,200 mg, administered in two equally divided doses, is reached. It is not known whether doses lower than the target doses are effective.

Adults (17 years and older)

The recommended starting daily dose of rufinamide tablets in adults with Lennox-Gastaut Syndrome is 400 mg to 800 mg per day administered in two equally divided doses. The dose should be increased by 400 mg to 800 mg every other day until a maximum daily dose of 3,200 mg, administered in two equally divided doses, is reached. It is not known whether doses lower than 3,200 mg are effective.

100 mg Strength: Pink, oblong shaped, film-coated, with a score on both sides, and debossed with 'L', 'U' on each side of the score on one side and 'P', '71' on each side of the score on the other side.

200 mg Strength: Pink, oblong shaped, film-coated, with a score on both sides, and debossed with 'L', 'U' on each side of the score on one side and 'P', '72' on each side of the score on the other side.

400 mg Strength: Pink, oblong shaped, film-coated, with a score on both sides, and debossed with 'L', 'U' on each side of the score on one side and 'P', '73' on each side of the score on the other side.

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 1 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 1 shows absolute and relative risk by indication for all evaluated AEDs.

Somnolence was reported in 24% of rufinamide-treated patients compared to 13% of patients on placebo, and led to study discontinuation in 3% of rufinamide-treated patients compared to 0% of patients on placebo. Fatigue was reported in 10% of rufinamide-treated patients compared to 8% of patients on placebo patients. It led to study discontinuation in 1% of rufinamide-treated patients and 0% of patients on placebo patients.

Dizziness was reported in 2.7% of rufinamide-treated patients compared to 0% of patients on placebo, and did not lead to study discontinuation.

Ataxia and gait disturbance were reported in 5.4% and 1.4% of rufinamide-treated patients, respectively, compared to no patient on placebo. None of these reactions led to study discontinuation.

Accordingly, patients should be advised not to drive or operate machinery until they have gained sufficient experience on rufinamide to gauge whether it adversely affects their ability to drive or operate machinery.

Reductions of the QT interval below 300 msec were not observed in the formal QT studies with doses up to 7200 mg per day. Moreover, there was no signal for drug-induced sudden death or ventricular arrhythmias.

The degree of QT shortening induced by rufinamide is without any known clinical risk. Familial Short QT syndrome is associated with an increased risk of sudden death and ventricular arrhythmias, particularly ventricular fibrillation. Such events in this syndrome are believed to occur primarily when the corrected QT interval falls below 300 msec. Non-clinical data also indicate that QT shortening is associated with ventricular fibrillation.

Patients with Familial Short QT syndrome should not be treated with rufinamide. Caution should be used when administering rufinamide with other drugs that shorten the QT interval [see CONTRAINDICATIONS (4)].

All cases of DRESS identified in clinical trials with rufinamide occurred in pediatric patients less than 12 years of age, occurred within 4 weeks of treatment initiation, and resolved or improved with rufinamide discontinuation. DRESS has also been reported in adult and pediatric patients taking rufinamide in the postmarketing setting.

If DRESS is suspected, the patient should be evaluated immediately, rufinamide should be discontinued, and alternative treatment should be started.

Adverse Reactions in Adult and Pediatric Patients ages 3 to 17 years of age

In the pooled, double-blind, adjunctive therapy studies in adult and pediatric patients ages 3 to 17 years of age, the most common (≥10%) adverse reactions in rufinamide-treated patients, in all doses studied (200 to 3200 mg per day) with a higher frequency than in patients on placebo were: headache, dizziness, fatigue, somnolence, and nausea.

Table 2 lists adverse reactions that occurred in at least 3% of pediatric patients (ages 3 to less than 17 years) with epilepsy treated with rufinamide in controlled adjunctive studies and were numerically more common in patients treated with rufinamide than in patients on placebo.

At the target dose of 45 mg/kg per day for adjunctive therapy in pediatric patients (ages 3 to less than 17 years), the most common (≥3%) adverse reactions with an incidence greater than in placebo for rufinamide were somnolence, vomiting, and headache.

Dermatologic

Stevens-Johnson syndrome and other serious skin rashes with mucosal involvement.

Table 6 summarizes the drug-drug interactions of rufinamide with other AEDs.

Valproate

Patients stabilized on rufinamide before being prescribed valproate should begin valproate therapy at a low dose, and titrate to a clinically effective dose. Similarly, patients on valproate should begin at a rufinamide dose lower than 10 mg/kg per day (pediatric patients) or 400 mg per day (adults) [see USE IN SPECIFIC POPULATIONS (8.3), DOSAGE AND ADMINISTRATION (2.5), CLINICAL PHARMACOLOGY (12.3)].

There is a pregnancy exposure registry that monitors pregnancy outcomes in women exposed to AEDs, such as rufinamide, during pregnancy. Encourage women who are taking rufinamide 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 use of rufinamide in pregnant women. In animal reproduction studies, oral administration of rufinamide resulted in developmental toxicity in pregnant rats and rabbits at clinically relevant doses [see Data].

In the U.S. general population, the estimated background risk of major birth defects and miscarriage in clinically recognized pregnancies is 2 to 4% and 15 to 20%, respectively. The background risk of major birth defects and miscarriage for the indicated population is unknown.

Data

Animal data:

Oral administration of rufinamide (0, 20, 100 or 300 mg/kg/day) to pregnant rats throughout organogenesis resulted in decreased fetal weight and increased incidence of fetal skeletal abnormalities at 100 and 300 mg/kg/day, which were associated with maternal toxicity. The maternal plasma exposure (AUC) at the no-adverse effect dose (20 mg/kg/day) for developmental toxicity was less than that in humans at the maximum recommended human dose (MRHD) of 3,200 mg/day.

Oral administration of rufinamide (0, 30, 200 or 1,000 mg/kg/day) to pregnant rabbits throughout organogenesis resulted in embryofetal death, decreased fetal body weight and increased incidence of fetal visceral and skeletal abnormalities at doses of 200 and 1,000 mg/kg/day. The high dose (1000 mg/kg/day) was associated with abortion. Plasma exposure (AUC) at the no-adverse effect dose (30 mg/kg/day) was less than that in humans at the MRHD.

When rufinamide was orally administered (0, 5, 30 or 150 mg/kg/day) to pregnant rats throughout pregnancy and lactation, decreased offspring growth and survival were observed at all doses tested. A no-effect dose for adverse effects on pre- and postnatal development was not established. At the lowest dose tested (5 mg/kg/day), plasma exposure (AUC) was less than that in humans at the MRHD.

There are no data on the presence of rufinamide in human milk, the effects on the breastfed infant or the effects of the drug on milk production.

The developmental and health benefits of breastfeeding should be considered along with the mother's clinical need for rufinamide and any potential adverse effects on the breastfed infant from rufinamide or from the underlying maternal condition.

Use of rufinamide may reduce the effectiveness of hormonal contraceptives containing ethinyl estradiol or norethindrone. Advise women of reproductive potential taking rufinamide who are using a contraceptive containing ethinyl estradiol and norethindrone to use an additional non-hormonal form of contraception [see DRUG INTERACTIONS (7.3) and CLINICAL PHARMACOLOGY (12.3)].

Infertility

The effect of rufinamide on fertility in humans has not been established. Oral administration of rufinamide (20, 60, 200 and 600 mg/kg/day) to male and female rats prior to mating, during mating and during early gestation (females only) resulted in the impairment of fertility at all dose levels tested. The no-effect dose was not established. The plasma exposure level at 20 mg/kg was approximately 0.2 times the human plasma AUC at the MRHD [see NONCLINICAL TOXICOLOGY (13.1)].

Safety and effectiveness in pediatric patients below the age of 1 year has not been established.

Oral administration of rufinamide (0, 15, 50 or 150 mg/kg) to young rats for 10 weeks starting on postnatal day 7 resulted in decreased brain weights at the mid and high doses and neurobehavioral impairment (learning and memory deficit, altered startle response, decreased locomotor activity) and decreased growth (decreased body weight) at the highest dose tested. The no-effect dose for adverse effects on postnatal development in rats (15 mg/kg) was associated with a plasma exposure (AUC) lower than that in humans at the maximum recommended human dose (MRHD) of 3200 mg/day.

Pharmacokinetics of rufinamide in the elderly are similar to that in the young subjects [see CLINICAL PHARMACOLOGY (12.3)].

One overdose of 7200 mg per day rufinamide was reported in an adult during the clinical trials. The overdose was associated with no major signs or symptoms, no medical intervention was required, and the patient continued in the study at the target dose.

Treatment or Management of Overdose:

There is no specific antidote for overdose with rufinamide. If clinically indicated, elimination of unabsorbed drug should be attempted by induction of emesis or gastric lavage. Usual precautions should be observed to maintain the airway. General supportive care of the patient is indicated including monitoring of vital signs and observation of the clinical status of the patient.

Hemodialysis:

Standard hemodialysis procedures may result in limited clearance of rufinamide. Although there is no experience to date in treating overdose with hemodialysis, the procedure may be considered when indicated by the patient's clinical state.

The results of in vitro studies suggest that the principal mechanism of action of rufinamide is modulation of the activity of sodium channels and, in particular, prolongation of the inactive state of the channel. Rufinamide (≥ 1 µgM) significantly slowed sodium channel recovery from inactivation after a prolonged prepulse in cultured cortical neurons, and limited sustained repetitive firing of sodium-dependent action potentials (EC₅₀ of 3.8 µgM).

Rufinamide is well absorbed after oral administration. However, the rate of absorption is relatively slow and the extent of absorption is decreased as dose is increased. The pharmacokinetics does not change with multiple dosing. Most elimination of rufinamide is via metabolism, with the primary metabolite resulting from enzymatic hydrolysis of the carboxamide moiety to form the carboxylic acid. This metabolic route is not cytochrome P450 dependent. There are no known active metabolites. Plasma half-life of rufinamide is approximately 6 to 10 hours.

Absorption and Distribution

Following oral administration of rufinamide, peak plasma concentrations occur between 4 and 6 hours (T_max) both under fed and fasted conditions. Rufinamide tablets display decreasing bioavailability with increasing dose after single and multiple dose administration. Based on urinary excretion, the extent of absorption was at least 85% following oral administration of a single dose of 600 mg rufinamide tablet under fed conditions.

Multiple dose pharmacokinetics can be predicted from single dose data for both rufinamide and its metabolite. Given the dosing frequency of every 12 hours and the half-life of 6 to 10 hours, the observed steady-state peak concentration of about two to three times the peak concentration after a single dose is expected.

Food increased the extent of absorption of rufinamide in healthy volunteers by 34% and increased peak exposure by 56% after a single dose of 400 mg tablet, although the T_max was not elevated [see DOSAGE AND ADMINISTRATION (2.2)]. 

Only a small fraction of rufinamide (34%) is bound to human serum proteins, predominantly to albumin (27%), giving little risk of displacement drug-drug interactions. Rufinamide was evenly distributed between erythrocytes and plasma. The apparent volume of distribution is dependent upon dose and varies with body surface area. The apparent volume of distribution was about 50 L at 3200 mg per day.

Metabolism

Rufinamide is extensively metabolized but has no active metabolites. Following a radiolabeled dose of rufinamide, less than 2% of the dose was recovered unchanged in urine. The primary biotransformation pathway is carboxylesterase(s) mediated hydrolysis of the carboxamide group to the acid derivative CGP 47292. A few minor additional metabolites were detected in urine, which appeared to be acyl-glucuronides of CGP 47292. There is no involvement of oxidizing cytochrome P450 enzymes or glutathione in the biotransformation process.

Rufinamide is a weak inhibitor of CYP 2E1. It did not show significant inhibition of other CYP enzymes. Rufinamide is a weak inducer of CYP 3A4 enzymes.

Rufinamide did not show any significant inhibition of P-glycoprotein in an in-vitro study.

Elimination/Excretion

Renal excretion is the predominant route of elimination for drug related material, accounting for 85% of the dose based on a radiolabeled study. Of the metabolites identified in urine, at least 66% of the rufinamide dose was excreted as the acid metabolite CGP 47292, with 2% of the dose excreted as rufinamide.

The plasma elimination half-life is approximately 6 to 10 hours in healthy subjects and patients with epilepsy.

Special Populations

Age:

• Pediatrics

Based on a population analysis which included a total of 115 patients, including 85 pediatric patients (24 patients ages 1 to 3 years, 40 patients ages 4 to 11 years and 21 patients ages 12 to 17 years), the pharmacokinetics of rufinamide was similar across all age groups.

• Elderly

The results of a study evaluating single-dose (400 mg) and multiple dose (800 mg per day for 6 days) pharmacokinetics of rufinamide in 8 healthy elderly subjects (65 to 80 years old) and 7 younger healthy subjects (18 to 45 years old) found no significant age-related differences in the pharmacokinetics of rufinamide.

Sex:

Population pharmacokinetic analyses of females show a 6 to 14% lower apparent clearance of rufinamide compared to males. This effect is not clinically important.

Race :

In a population pharmacokinetic analysis of clinical studies, no difference in clearance or volume of distribution of rufinamide was observed between the black and Caucasian subjects, after controlling for body size. Information on other races could not be obtained because of smaller numbers of these subjects.

Renal Impairment:

Rufinamide pharmacokinetics in 9 patients with severe renal impairment (creatinine clearance < 30 mL per min) was similar to that of healthy subjects. Patients undergoing dialysis 3 hours post rufinamide dosing showed a reduction in AUC and C_max by 29% and 16%, respectively.

Drug Interactions

Based on in vitro studies, rufinamide shows little or no inhibition of most cytochrome P450 enzymes at clinically relevant concentrations, with weak inhibition of CYP 2E1. Drugs that are substrates of CYP 2E1 (e.g., chlorzoxazone) may have increased plasma levels in the presence of rufinamide, but this has not been studied.

Based on a population pharmacokinetic analysis, rufinamide clearance was decreased by valproate. In pediatric patients, valproate administration may lead to elevated levels of rufinamide by up to 70% [see DRUG INTERACTIONS (7.2)].

Based on in vivo drug interaction studies with triazolam and oral contraceptives, rufinamide is a weak inducer of the CYP 3A4 enzyme and can decrease exposure of drugs that are substrates of CYP 3A4.

Rufinamide was given in the diet to mice at 40, 120, and 400 mg/kg per day and to rats at 20, 60, and 200 mg/kg per day for 2 years. The doses in mice were associated with plasma AUCs 0.1 to 1 times the human plasma AUC at the maximum recommended human dose (MRHD, 3200 mg/day). Increased incidences of tumors (benign bone tumors (osteomas) and/or hepatocellular adenomas and carcinomas) were observed in mice at all doses. Increased incidences of thyroid follicular adenomas were observed in rats at all but the low dose; the low dose is <0.1 times the MRHD on a mg/m²basis.

Mutagenesis

Rufinamide was not mutagenic in the in vitro bacterial reverse mutation (Ames) assay or the in vitro mammalian cell point mutation assay. Rufinamide was not clastogenic in the in vitro mammalian cell chromosomal aberration assay or the in vivo rat bone marrow micronucleus assay.

Impairment of Fertility

Oral administration of rufinamide (doses of 20, 60, 200, and 600 mg/kg per day) to male and female rats prior to mating, and throughout mating, and continuing in females up to day 6 of gestation resulted in impairment of fertility (decreased conception rates and mating and fertility indices; decreased numbers of corpora lutea, implantations, and live embryos; increased preimplantation loss; decreased sperm count and motility) at all doses tested. Therefore, a no-effect dose was not established. The lowest dose tested was associated with a plasma AUC ≈ 0.2 times the human plasma AUC at the MRHD.

Rufinamide tablets USP, 100 mg (containing 100 mg rufinamide) are pink, oblong shaped, film-coated, with a score on both sides, and debossed with 'L', 'U' on each side of the score on one side and 'P', '71' on each side of the score on the other side. They are available in bottles of 30 tablets (NDC 68180-802-06) and 120 tablets (NDC 68180-802-16).

Rufinamide tablets USP, 200 mg (containing 200 mg rufinamide) are pink, oblong shaped, film-coated, with a score on both sides, and debossed with 'L', 'U' on each side of the score on one side and 'P', '72' on each side of the score on the other side. They are available in bottles of 30 tablets (NDC 68180-803-06) and 120 tablets (NDC 68180-803-16).

Rufinamide tablets USP, 400 mg (containing 400 mg rufinamide) are pink, oblong shaped, film-coated, with a score on both sides, and debossed with 'L', 'U' on each side of the score on one side and 'P', '73' on each side of the score on the other side. They are available in bottles of 120 tablets (NDC 68180-804-16).

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Administration Information