Monotherapy and Adjunctive Therapy
The recommended dosage for adults and pediatric patients 4 years to less than 17 years of age is included in Table 1. In pediatric patients 4 years to less than 17 years of age, the recommended dosing regimen is dependent upon body weight and is only recommended to be administered orally. Dosage should be increased based on clinical response and tolerability, no more frequently than once per week. Titration increments should not exceed those shown in Table 1.
Table 1: Recommended Dosage for Adults and Pediatric Patients 4 Years and Older
| Age and Body Weight | Initial Dosage | Titration Regimen | Maintenance Dosage |
|---|
| Adults (17 years and older) | Monotherapy: 100 mg twice daily
(200 mg per day)
Adjunctive Therapy: 50 mg twice daily
(100 mg per day)
| Increase by 50 mg twice daily
(100 mg per day)
every week
| Monotherapy: 150 mg to 200 mg twice daily
(300 mg to 400 mg per day)
Adjunctive Therapy: 100 mg to 200 mg twice daily
(200 mg to 400 mg per day)
|
| | Alternate Initial Dosage: 200 mg single loading dose, followed 12 hours later by 100 mg twice daily
| | |
| Pediatric patients weighing 50 kg or more | 50 mg twice daily
(100 mg per day)
| Increase by 50 mg twice daily (100 mg per day) every week | Monotherapy: 150 mg to 200 mg twice daily
(300 mg to 400 mg per day)
Adjunctive Therapy: 100 mg to 200 mg twice daily
(200 mg to 400 mg per day)
|
| Pediatric patients weighing 30 kg to less than 50 kg | 1 mg/kg twice daily
(2 mg/kg/day)
| Increase by 1 mg/kg twice daily (2 mg/kg/day) every week | 2 mg/kg to 4 mg/kg twice daily
(4 mg/kg/day to 8 mg/kg/day)
|
| Pediatric patients weighing 11 kg to less than 30 kg | 1 mg/kg twice daily
(2 mg/kg/day)
| Increase by 1 mg/kg twice daily (2 mg/kg/day) every week | 3 mg/kg to 6 mg/kg twice daily
(6 mg/kg/day to 12 mg/kg/day)
|
In adjunctive clinical trials in adult patients, a dosage higher than 200 mg twice daily (400 mg per day) was not more effective and was associated with a substantially higher rate of adverse reactions [
see
Adverse Reactions (6.1) and
Clinical Studies (14.2)].
VIMPAT Injection Dosage in Adult Patients (17 years and older)
VIMPAT injection may be used for adult patients when oral administration is temporarily not feasible [
see
Dosage and Administration (2.6) and
Warnings and Precautions (5.3)]
. VIMPAT injection can be administered intravenously to adult patients with the same dosing regimens described for oral dosing, including the loading dose. The use of VIMPAT injection in pediatric patients has not been studied.
The clinical study experience of intravenous VIMPAT is limited to 5 days of consecutive treatment.
Loading Dose in Adult Patients (17 Years and Older)
VIMPAT and VIMPAT injection may be initiated in adult patients with a single loading dose of 200 mg, followed approximately 12 hours later by 100 mg twice daily (200 mg per day). This maintenance dose regimen should be continued for one week. VIMPAT can then be titrated as recommended in Table 1. The adult loading dose should be administered with medical supervision because of the increased incidence of CNS adverse reactions [
see
Adverse Reactions (6.1),
Clinical Pharmacology (12.3)].
The use of a loading dose in pediatric patients has not been studied.
Hemodialysis
VIMPAT is effectively removed from plasma by hemodialysis. Following a 4-hour hemodialysis treatment, dosage supplementation of up to 50% should be considered.
Concomitant Strong CYP3A4 or CYP2C9 Inhibitors
Dose reduction may be necessary in patients with renal impairment who are taking strong inhibitors of CYP3A4 and CYP2C9 [
see
Drug Interactions (7.1),
Use in Specific Populations (8.6),
Clinical Pharmacology (12.3)].
Concomitant Strong CYP3A4 and CYP2C9 Inhibitors
Dose reduction may be necessary in patients with hepatic impairment who are taking strong inhibitors of CYP3A4 and CYP2C9 [
see
Drug Interactions (7.1),
Use in Specific Populations (8.7),
Clinical Pharmacology (12.3)].
VIMPAT Oral Solution
A calibrated measuring device is recommended to measure and deliver the prescribed dose accurately. A household teaspoon or tablespoon is not an adequate measuring device.
VIMPAT oral solution may also be administered using a nasogastric tube or gastrostomy tube.
Discard any unused VIMPAT oral solution remaining after 7 weeks of first opening the bottle.
Preparation
VIMPAT injection can be administered intravenously without further dilution or may be mixed with diluents listed below. The diluted solution should not be stored for more than 4 hours at room temperature.
Diluents:
Sodium Chloride Injection 0.9% (w/v)
Dextrose Injection 5% (w/v)
Lactated Ringer's Injection
Parenteral drug products should be inspected visually for particulate matter and discoloration prior to administration, whenever solution and container permit. Product with particulate matter or discoloration should not be used.
VIMPAT injection is for single-dose only. Any unused portion of VIMPAT injection should be discarded.
Administration
The recommended infusion rate is 30 to 60 minutes; however, infusions as rapid as 15 minutes can be administered if required [
see
Adverse Reactions (6.1),
Clinical Pharmacology (12.3)]
.
Intravenous infusion of VIMPAT may cause bradycardia or AV blocks [
see
Warnings and Precautions (5.3)]. Obtaining an ECG before beginning VIMPAT and after VIMPAT is titrated to steady-state maintenance dose is recommended in patients with known cardiac conduction problems, on concomitant medications that prolong PR interval, or with severe cardiac disease.
Storage and Stability
The diluted solution should not be stored for more than 4 hours at room temperature. Any unused portion of VIMPAT injection should be discarded.
PR interval prolongation
Dose-dependent prolongations in PR interval with VIMPAT have been observed in clinical studies in adult patients and in healthy volunteers [
see
Clinical Pharmacology (12.2)]. In adjunctive clinical trials in adult patients with partial-onset seizures, asymptomatic first-degree atrioventricular (AV) block was observed as an adverse reaction in 0.4% (4/944) of patients randomized to receive VIMPAT and 0% (0/364) of patients randomized to receive placebo. In clinical trials in adult patients with diabetic neuropathy, for which VIMPAT is not indicated, asymptomatic first-degree AV block was observed as an adverse reaction in 0.5% (5/1023) of patients receiving VIMPAT and 0% (0/291) of patients receiving placebo. Second degree and complete AV block have been reported in patients with seizures. When VIMPAT is given with other drugs that prolong the PR interval, further PR prolongation is possible.
VIMPAT should be used with caution in patients with known conduction problems (e.g., marked first-degree AV block, second-degree or higher AV block and sick sinus syndrome without pacemaker), sodium channelopathies (e.g., Brugada Syndrome), on concomitant medications that prolong PR interval, or with severe cardiac disease such as myocardial ischemia or heart failure, or structural heart disease. In such patients, obtaining an ECG before beginning VIMPAT, and after VIMPAT is titrated to steady-state maintenance dose, is recommended. In addition, these patients should be closely monitored if they are administered VIMPAT through the intravenous route. One case of profound bradycardia was observed in a patient during a 15-minute infusion of 150 mg VIMPAT. There were two postmarketing reports of third degree AV block in patients with significant cardiac history and also receiving metoprolol and amlodipine during infusion of VIMPAT injection at doses higher than recommended [
see
Adverse Reactions (6.1),
Drug Interactions (7.2)]
.
Atrial fibrillation and Atrial flutter
In the short-term investigational trials of VIMPAT in adult patients with partial-onset seizures there were no cases of atrial fibrillation or flutter. Both atrial fibrillation and atrial flutter have been reported in open label partial-onset seizure trials and in postmarketing experience. In adult patients with diabetic neuropathy, 0.5% of patients treated with VIMPAT experienced an adverse reaction of atrial fibrillation or atrial flutter, compared to 0% of placebo-treated patients. VIMPAT administration may predispose to atrial arrhythmias (atrial fibrillation or flutter), especially in patients with diabetic neuropathy and/or cardiovascular disease.
VIMPAT Tablet and Oral Solution
In the premarketing development of adjunctive therapy for partial-onset seizures, 1327 adult patients received VIMPAT tablets in controlled and uncontrolled trials, of whom 1000 were treated for longer than 6 months, and 852 for longer than 12 months. The monotherapy development program included 425 adult patients, 310 of whom were treated for longer than 6 months, and 254 for longer than 12 months.
Monotherapy Historical-Control Trial (Study 1)
In the monotherapy trial, 16% of patients randomized to receive VIMPAT at the recommended doses of 300 and 400 mg/day discontinued from the trial as a result of an adverse reaction. The adverse reaction most commonly (≥1% on VIMPAT) leading to discontinuation was dizziness.
Adverse reactions that occurred in this study were generally similar to those that occurred in adjunctive placebo-controlled studies. One adverse reaction, insomnia, occurred at a rate of ≥2% and was not reported at a similar rate in previous studies. This adverse reaction has also been observed in postmarketing experience [
see
Adverse Reactions (6.2)]. Because this study did not include a placebo control group, causality could not be established.
Dizziness, headache, nausea, somnolence, and fatigue all occurred at lower incidences during the AED Withdrawal Phase and Monotherapy Phase, compared with the Titration Phase [
see
Clinical Studies (14.1)].
Adjunctive Therapy Controlled Trials (Studies 2, 3, and 4)
In adjunctive therapy controlled clinical trials, the rate of discontinuation as a result of an adverse reaction was 8% and 17% in patients randomized to receive VIMPAT at the recommended doses of 200 and 400 mg/day, respectively, 29% at 600 mg/day (1.5 times greater than the maximum recommended dose), and 5% in patients randomized to receive placebo. The adverse reactions most commonly (>1% on VIMPAT and greater than placebo) leading to discontinuation were dizziness, ataxia, vomiting, diplopia, nausea, vertigo, and blurred vision.
Table 3 gives the incidence of adverse reactions that occurred in ≥2% of adult patients with partial-onset seizures in the VIMPAT total group and for which the incidence was greater than placebo.
Table 3: Adverse Reactions Incidence in Adjunctive Therapy Pooled, Placebo-Controlled Trials in Adult Patients with Partial-Onset Seizures (Studies 2, 3, and 4)| Adverse Reaction | Placebo
N=364
%
| VIMPAT
200 mg/day
N=270
%
| VIMPAT
400 mg/day
N=471
%
| VIMPAT
600 mg/day
N=203
%
| VIMPAT
Total
N=944
%
|
|---|
| Ear and labyrinth disorder |
| Vertigo | 1 | 5 | 3 | 4 | 4 |
| Eye disorders |
| Diplopia | 2 | 6 | 10 | 16 | 11 |
| Blurred Vision | 3 | 2 | 9 | 16 | 8 |
| Gastrointestinal disorders |
| Nausea | 4 | 7 | 11 | 17 | 11 |
| Vomiting | 3 | 6 | 9 | 16 | 9 |
| Diarrhea | 3 | 3 | 5 | 4 | 4 |
| General disorders and administration site conditions |
| Fatigue | 6 | 7 | 7 | 15 | 9 |
| Gait disturbance | <1 | <1 | 2 | 4 | 2 |
| Asthenia | 1 | 2 | 2 | 4 | 2 |
| Injury, poisoning and procedural complications |
| Contusion | 3 | 3 | 4 | 2 | 3 |
| Skin laceration | 2 | 2 | 3 | 3 | 3 |
| Nervous system disorders |
| Dizziness | 8 | 16 | 30 | 53 | 31 |
| Headache | 9 | 11 | 14 | 12 | 13 |
| Ataxia | 2 | 4 | 7 | 15 | 8 |
| Somnolence | 5 | 5 | 8 | 8 | 7 |
| Tremor | 4 | 4 | 6 | 12 | 7 |
| Nystagmus | 4 | 2 | 5 | 10 | 5 |
| Balance disorder | 0 | 1 | 5 | 6 | 4 |
| Memory impairment | 2 | 1 | 2 | 6 | 2 |
| Psychiatric disorders |
| Depression | 1 | 2 | 2 | 2 | 2 |
| Skin and subcutaneous disorders |
| Pruritus | 1 | 3 | 2 | 3 | 2 |
The overall adverse reaction rate was similar in male and female patients. Although there were few non-Caucasian patients, no differences in the incidences of adverse reactions compared to Caucasian patients were observed.
Pediatric Patients (4 to less than 17 Years of Age)
Safety of VIMPAT was evaluated in clinical studies of pediatric patients 4 to less than 17 years of age for the treatment of partial-onset seizures. Across studies in pediatric patients with partial-onset seizures, 328 patients 4 to less than 17 years of age received VIMPAT oral solution or tablet, of whom 148 received VIMPAT for at least 1 year. Adverse reactions reported in clinical studies of pediatric patients 4 to less than 17 years of age were similar to those seen in adult patients.
Laboratory Abnormalities
Abnormalities in liver function tests have occurred in controlled trials with VIMPAT in adult patients with partial-onset seizures who were taking 1 to 3 concomitant anti-epileptic drugs. Elevations of ALT to ≥3× ULN occurred in 0.7% (7/935) of VIMPAT patients and 0% (0/356) of placebo patients
. One case of hepatitis with transaminases >20× ULN occurred in one healthy subject 10 days after VIMPAT treatment completion, along with nephritis (proteinuria and urine casts). Serologic studies were negative for viral hepatitis. Transaminases returned to normal within one month without specific treatment. At the time of this event, bilirubin was normal. The hepatitis/nephritis was interpreted as a delayed hypersensitivity reaction to VIMPAT.
Other Adverse Reactions
The following is a list of adverse reactions reported by patients treated with VIMPAT in all clinical trials in adult patients with partial-onset seizures, including controlled trials and long-term open-label extension trials. Adverse reactions addressed in other tables or sections are not listed here.
Blood and lymphatic system disorders: neutropenia, anemia
Cardiac disorders: palpitations
Ear and labyrinth disorders: tinnitus
Gastrointestinal disorders: constipation, dyspepsia, dry mouth, oral hypoaesthesia
General disorders and administration site conditions: irritability, pyrexia, feeling drunk
Injury, poisoning, and procedural complications: fall
Musculoskeletal and connective tissue disorders: muscle spasms
Nervous system disorders: paresthesia, cognitive disorder, hypoaesthesia, dysarthria, disturbance in attention, cerebellar syndrome
Psychiatric disorders: confusional state, mood altered, depressed mood
VIMPAT Injection
Adverse reactions with intravenous administration to adult patients generally were similar to those that occurred with the oral formulation, although intravenous administration was associated with local adverse reactions such as injection site pain or discomfort (2.5%), irritation (1%), and erythema (0.5%). One case of profound bradycardia (26 bpm: BP 100/60 mmHg) occurred in a patient during a 15-minute infusion of 150 mg VIMPAT. This patient was on a beta-blocker. Infusion was discontinued and the patient experienced a rapid recovery.
The safety of a 15-minute loading dose administration of VIMPAT Injection 200 mg to 400 mg followed by oral administration of VIMPAT given twice daily at the same total daily dose as the initial intravenous infusion was assessed in an open-label study in adult patients with partial-onset seizures. Patients had to have been maintained on a stable dose regimen of 1 to 2 marketed antiepileptics for at least 28 days prior to treatment assignment. Treatment groups were as follows:
- Single dose of intravenous VIMPAT Injection 200 mg followed by oral VIMPAT 200 mg/day (100 mg every 12 hours)
- Single dose of intravenous VIMPAT Injection 300 mg followed by oral VIMPAT 300 mg/day (150 mg every 12 hours)
- Single dose of intravenous VIMPAT Injection 400 mg followed by oral VIMPAT 400 mg/day (200 mg every 12 hours).
Table 4 gives the incidence of adverse reactions that occurred in ≥5% of adult patients in any VIMPAT dosing group.
Table 4: Adverse Reactions in a 15-minute Infusion Study in Adult Patients with Partial-Onset Seizures| Adverse Reaction | VIMPAT
200 mg
N=25
%
| VIMPAT
300 mg
N=50
%
| VIMPAT
400 mg
N=25
%
| VIMPAT
Total
N=100
%
|
|---|
| Eye disorders | | | | |
| Diplopia | 4 | 6 | 20 | 9 |
| Blurred Vision | 0 | 4 | 12 | 5 |
| Gastrointestinal disorders | | | | |
| Nausea | 0 | 16 | 24 | 14 |
| Dry mouth | 0 | 6 | 12 | 6 |
| Vomiting | 0 | 4 | 12 | 5 |
| Oral Paresthesia | 4 | 4 | 8 | 5 |
| Oral Hypoesthesia | 0 | 6 | 8 | 5 |
| Diarrhea | 0 | 8 | 0 | 4 |
| General disorders/administration site conditions | | | | |
| Fatigue | 0 | 18 | 12 | 12 |
| Gait disturbance | 8 | 2 | 0 | 3 |
| Chest pain | 0 | 0 | 12 | 3 |
| Nervous system disorders | | | | |
| Dizziness | 20 | 46 | 60 | 43 |
| Somnolence | 0 | 34 | 36 | 26 |
| Headache | 8 | 4 | 16 | 8 |
| Paresthesia | 8 | 6 | 4 | 6 |
| Tremor | 0 | 6 | 4 | 4 |
| Abnormal Coordination | 0 | 6 | 0 | 3 |
| Skin & subcutaneous tissue disorders | | | | |
| Pruritus | 0 | 6 | 4 | 4 |
| Hyperhidrosis | 0 | 0 | 8 | 2 |
Adverse reactions that occurred with infusion of VIMPAT 200 mg over 15-minutes followed by VIMPAT 100 mg administered orally twice per day were similar in frequency to those that occurred in 3-month adjunctive therapy controlled trials. Considering the difference in period of observations (1 week vs. 3 months), the incidence of CNS adverse reactions, such as dizziness, somnolence, and paresthesia may be higher with 15-minute administration of VIMPAT Injection than with administration over a 30-to 60-minute period.
Pregnancy Exposure Registry
There is a pregnancy exposure registry that monitors pregnancy outcomes in women exposed to antiepileptic drugs (AEDs), such as VIMPAT, during pregnancy. Encourage women who are taking VIMPAT 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 VIMPAT in pregnant women.
Lacosamide produced developmental toxicity (increased embryofetal and perinatal mortality, growth deficit) in rats following administration during pregnancy. Developmental neurotoxicity was observed in rats following administration during a period of postnatal development corresponding to the third trimester of human pregnancy. These effects were observed at doses associated with clinically relevant plasma exposures
(see
Data)
.
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.
Data
Animal Data
Oral administration of lacosamide to pregnant rats (20, 75, or 200 mg/kg/day) and rabbits (6.25, 12.5, or 25 mg/kg/day) during the period of organogenesis did not produce any effects on the incidences of fetal structural abnormalities. However, the maximum doses evaluated were limited by maternal toxicity in both species and embryofetal death in rats. These doses were associated with maternal plasma lacosamide exposures (AUC) approximately 2 and 1 times (rat and rabbit, respectively) that in humans at the maximum recommended human dose (MRHD) of 400 mg/day.
In two studies in which lacosamide (25, 70, or 200 mg/kg/day and 50, 100, or 200 mg/kg/day) was orally administered to rats throughout pregnancy and lactation, increased perinatal mortality and decreased body weights in the offspring were observed at the highest dose tested. The no-effect dose for pre- and postnatal developmental toxicity in rats (70 mg/kg/day) was associated with a maternal plasma lacosamide AUC similar to that in humans at the MRHD.
Oral administration of lacosamide (30, 90, or 180 mg/kg/day) to rats during the neonatal and juvenile periods of development resulted in decreased brain weights and long-term neurobehavioral changes (altered open field performance, deficits in learning and memory). The early postnatal period in rats is generally thought to correspond to late pregnancy in humans in terms of brain development. The no-effect dose for developmental neurotoxicity in rats was associated with a plasma lacosamide AUC less than that in humans at the MRHD.
In Vitro Data
Lacosamide has been shown
in vitro to interfere with the activity of collapsin response mediator protein-2 (CRMP-2), a protein involved in neuronal differentiation and control of axonal outgrowth. Potential adverse effects on CNS development related to this activity cannot be ruled out.
Risk Summary
There are no data on the presence of lacosamide in human milk, the effects on the breastfed infant, or the effects on milk production. Studies in lactating rats have shown excretion of lacosamide and/or its metabolites in milk.
The developmental and health benefits of breastfeeding should be considered along with the mother's clinical need for VIMPAT and any potential adverse effects on the breastfed infant from VIMPAT or from the underlying maternal condition.
Animal Data
Lacosamide has been shown
in vitro to interfere with the activity of collapsin response mediator protein-2 (CRMP-2), a protein involved in neuronal differentiation and control of axonal outgrowth. Potential related adverse effects on CNS development cannot be ruled out. Administration of lacosamide to rats during the neonatal and juvenile periods of postnatal development (approximately equivalent to neonatal through adolescent development in humans) resulted in decreased brain weights and long-term neurobehavioral changes (altered open field performance, deficits in learning and memory). The no-effect dose for developmental neurotoxicity in rats was associated with a plasma lacosamide exposure (AUC) less than that in humans at the maximum recommended human dose of 400 mg/day.
Cardiac Electrophysiology
Electrocardiographic effects of VIMPAT were determined in a double-blind, randomized clinical pharmacology trial of 247 healthy subjects. Chronic oral doses of 400 and 800 mg/day were compared with placebo and a positive control (400 mg moxifloxacin). VIMPAT did not prolong QTc interval and did not have a dose-related or clinically important effect on QRS duration. VIMPAT produced a small, dose-related increase in mean PR interval. At steady-state, the time of the maximum observed mean PR interval corresponded with t
max. The placebo-subtracted maximum increase in PR interval (at t
max) was 7.3 ms for the 400 mg/day group and 11.9 ms for the 800 mg/day group. For patients who participated in the controlled trials, the placebo-subtracted mean maximum increase in PR interval for a 400 mg/day VIMPAT dose was 3.1 ms in patients with partial-onset seizures and 9.4 ms for patients with diabetic neuropathy.
Absorption and Bioavailability
VIMPAT is completely absorbed after oral administration. The oral bioavailability of VIMPAT tablets is approximately 100%. Food does not affect the rate and extent of absorption.
After intravenous administration, C
max is reached at the end of infusion. The 30- and 60-minute intravenous infusions are bioequivalent to the oral tablet. For the 15-minute intravenous infusion, bioequivalence was met for AUC
(0-tz) but not for C
max. The point estimate of C
max was 20% higher than C
max for oral tablet and the 90% CI for C
max exceeded the upper boundary of the bioequivalence range.
In a trial comparing the oral tablet with an oral solution containing 10 mg/mL lacosamide, bioequivalence between both formulations was shown.
A single loading dose of 200 mg approximates steady-state concentrations comparable to the 100 mg twice daily oral administration.
Distribution
The volume of distribution is approximately 0.6 L/kg and thus close to the volume of total body water. VIMPAT is less than 15% bound to plasma proteins.
Metabolism and Elimination
VIMPAT is primarily eliminated from the systemic circulation by renal excretion and biotransformation.
After oral and intravenous administration of 100 mg [14C]-lacosamide approximately 95% of radioactivity administered was recovered in the urine and less than 0.5% in the feces. The major compounds excreted were unchanged lacosamide (approximately 40% of the dose), its O-desmethyl metabolite (approximately 30%), and a structurally unknown polar fraction (~20%). The plasma exposure of the major human metabolite, O-desmethyl-lacosamide, is approximately 10% of that of lacosamide. This metabolite has no known pharmacological activity.
The CYP isoforms mainly responsible for the formation of the major metabolite (O-desmethyl) are CYP3A4, CYP2C9, and CYP2C19. The elimination half-life of the unchanged drug is approximately 13 hours and is not altered by different doses, multiple dosing or intravenous administration.
There is no enantiomeric interconversion of lacosamide.
Specific Populations
Renal Impairment
Lacosamide and its major metabolite are eliminated from the systemic circulation primarily by renal excretion.
The AUC of VIMPAT was increased approximately 25% in mildly (CL
CR 50-80 mL/min) and moderately (CL
CR 30-50 mL/min) and 60% in severely (CL
CR≤30 mL/min) renally impaired patients compared to subjects with normal renal function (CL
CR>80 mL/min), whereas C
max was unaffected. VIMPAT is effectively removed from plasma by hemodialysis. Following a 4-hour hemodialysis treatment, AUC of VIMPAT is reduced by approximately 50% [
see
Dosage and Administration (2.3)].
Hepatic Impairment
Lacosamide undergoes metabolism. Subjects with moderate hepatic impairment (Child-Pugh B) showed higher plasma concentrations of lacosamide (approximately 50-60% higher AUC compared to healthy subjects). The pharmacokinetics of lacosamide have not been evaluated in severe hepatic impairment [
see
Dosage and Administration (2.4)].
Pediatric Patients (4 to less than 17 Years of Age)
The pediatric pharmacokinetic profile of VIMPAT was determined in a population pharmacokinetic analysis using sparse plasma concentration data obtained in two open-label studies in 79 pediatric patients with partial-onset seizures that included patients 4 years to less than 17 years of age. Both apparent clearance and apparent volume of distribution increase as body weight increases. For patients weighing 11 kg, 28.9 kg (the mean population body weight), and 70 kg, the typical plasma half-life (t
1/2) is 7.4 hours, 10.6 hours, and 14.8 hours, respectively. Steady state plasma concentrations are achieved after 3 days of twice daily repeated administration.
The pharmacokinetics of VIMPAT in pediatric patients are similar when used as monotherapy or as adjunctive therapy for the treatment of partial-onset seizures.
Geriatric Patients
In the elderly (>65 years), dose and body-weight normalized AUC and C
max is about 20% increased compared to young subjects (18-64 years). This may be related to body weight and decreased renal function in elderly subjects.
Gender
VIMPAT clinical trials indicate that gender does not have a clinically relevant influence on the pharmacokinetics of VIMPAT.
Race
There are no clinically relevant differences in the pharmacokinetics of VIMPAT between Asian, Black, and Caucasian subjects.
CYP2C19 Polymorphism
There are no clinically relevant differences in the pharmacokinetics of VIMPAT between CYP2C19 poor metabolizers and extensive metabolizers. Results from a trial in poor metabolizers (PM) (N=4) and extensive metabolizers (EM) (N=8) of cytochrome P450 (CYP) 2C19 showed that lacosamide plasma concentrations were similar in PMs and EMs, but plasma concentrations and the amount excreted into urine of the O-desmethyl metabolite were about 70% reduced in PMs compared to EMs.
Drug Interactions
In Vitro Assessment of Drug Interactions
In vitro metabolism studies indicate that lacosamide does not induce the enzyme activity of drug metabolizing cytochrome P450 isoforms CYP1A2, 2B6, 2C9, 2C19 and 3A4. Lacosamide did not inhibit CYP 1A1, 1A2, 2A6, 2B6, 2C8, 2C9, 2D6, 2E1, 3A4/5 at plasma concentrations observed in clinical studies.
In vitro data suggest that lacosamide has the potential to inhibit CYP2C19 at therapeutic concentrations. However, an
in vivo study with omeprazole did not show an inhibitory effect on omeprazole pharmacokinetics.
Lacosamide was not a substrate or inhibitor for P-glycoprotein.
Lacosamide is a substrate of CYP3A4, CYP2C9, and CYP2C19. Patients with renal or hepatic impairment who are taking strong inhibitors of CYP3A4 and CYP2C9 may have increased exposure to lacosamide.
Since <15% of lacosamide is bound to plasma proteins, a clinically relevant interaction with other drugs through competition for protein binding sites is unlikely.
In Vivo Assessment of Drug Interactions
- Drug interaction studies with AEDs
- Effect of VIMPAT on concomitant AEDs
VIMPAT 400 mg/day had no influence on the pharmacokinetics of 600 mg/day valproic acid and 400 mg/day carbamazepine in healthy subjects.
The placebo-controlled clinical studies in patients with partial-onset seizures showed that steady-state plasma concentrations of levetiracetam, carbamazepine, carbamazepine epoxide, lamotrigine, topiramate, oxcarbazepine monohydroxy derivative (MHD), phenytoin, valproic acid, phenobarbital, gabapentin, clonazepam, and zonisamide were not affected by concomitant intake of VIMPAT at any dose.
- Effect of concomitant AEDs on VIMPAT
Drug-drug interaction studies in healthy subjects showed that 600 mg/day valproic acid had no influence on the pharmacokinetics of 400 mg/day VIMPAT. Likewise, 400 mg/day carbamazepine had no influence on the pharmacokinetics of VIMPAT in a healthy subject study. Population pharmacokinetics results in patients with partial-onset seizures showed small reductions (15% to 20% lower) in lacosamide plasma concentrations when VIMPAT was coadministered with carbamazepine, phenobarbital or phenytoin.
- Drug-drug interaction studies with other drugs
- Digoxin
There was no effect of VIMPAT (400 mg/day) on the pharmacokinetics of digoxin (0.5 mg once daily) in a study in healthy subjects.
- Metformin
There were no clinically relevant changes in metformin levels following coadministration of VIMPAT (400 mg/day).
Metformin (500 mg three times a day) had no effect on the pharmacokinetics of VIMPAT (400 mg/day).
- Omeprazole
Omeprazole is a CYP2C19 substrate and inhibitor.
There was no effect of VIMPAT (600 mg/day) on the pharmacokinetics of omeprazole (40 mg single dose) in healthy subjects. The data indicated that lacosamide had little
in vivo inhibitory or inducing effect on CYP2C19.
Omeprazole at a dose of 40 mg once daily had no effect on the pharmacokinetics of VIMPAT (300 mg single dose). However, plasma levels of the O-desmethyl metabolite were reduced about 60% in the presence of omeprazole.
- Midazolam
Midazolam is a 3A4 substrate.
There was no effect of VIMPAT (200 mg single dose or repeat doses of 400 mg/day given as 200 mg BID) on the pharmacokinetics of midazolam (single dose, 7.5 mg), indicating no inhibitory or inducing effects on CYP3A4.
- Oral Contraceptives
There was no influence of VIMPAT (400 mg/day) on the pharmacodynamics and pharmacokinetics of an oral contraceptive containing 0.03 mg ethinylestradiol and 0.15 mg levonorgestrel in healthy subjects, except that a 20% increase in ethinylestradiol C
max was observed.
- Warfarin
Co-administration of VIMPAT (400 mg/day) with warfarin (25 mg single dose) did not result in a clinically relevant change in the pharmacokinetic and pharmacodynamic effects of warfarin in a study in healthy male subjects.
Carcinogenesis
There was no evidence of drug related carcinogenicity in mice or rats. Mice and rats received lacosamide once daily by oral administration for 104 weeks at doses producing plasma exposures (AUC) up to approximately 1 and 3 times, respectively, the plasma AUC in humans at the maximum recommended human dose (MRHD) of 400 mg/day.
Mutagenesis
Lacosamide was negative in an
in vitro Ames test and an
in vivo mouse micronucleus assay. Lacosamide induced a positive response in the
in vitro mouse lymphoma assay.
Fertility
No adverse effects on male or female fertility or reproduction were observed in rats at doses producing plasma exposures (AUC) up to approximately 2 times the plasma AUC in humans at the MRHD.
VIMPAT (lacosamide) Tablets
- 50 mg are pink, oval, film-coated tablets debossed with "SP" on one side and "50" on the other. They are supplied as follows:
| Bottles of 60 | NDC 0131-2477-35 |
| Unit Dose Carton of 60 tablets [6 cards, each card contains 10 tablets] | NDC 0131-2477-60 |
- 100 mg are dark yellow, oval, film-coated tablets debossed with "SP" on one side and "100" on the other. They are supplied as follows:
| Bottles of 60 | NDC 0131-2478-35 |
| Unit Dose Carton of 60 tablets [6 cards, each card contains 10 tablets] | NDC 0131-2478-60 |
- 150 mg are salmon, oval, film-coated tablets debossed with "SP" on one side and "150" on the other. They are supplied as follows:
| Bottles of 60 | NDC 0131-2479-35 |
| Unit Dose Carton of 60 tablets [6 cards, each card contains 10 tablets] | NDC 0131-2479-60 |
- 200 mg are blue, oval, film-coated tablets debossed with "SP" on one side and "200" on the other. They are supplied as follows:
| Bottles of 60 | NDC 0131-2480-35 |
| Unit Dose Carton of 60 tablets [6 cards, each card contains 10 tablets] | NDC 0131-2480-60 |
VIMPAT (lacosamide) Injection
- 200 mg/20 mL is a clear, colorless sterile solution supplied in 20 mL colorless single-dose glass vials.
| 200 mg/20 mL vial in cartons of 10 vials | NDC 0131-1810-67 |
VIMPAT (lacosamide) Oral Solution
- 10 mg/mL is a clear, colorless to yellow or yellow-brown, strawberry-flavored liquid. It is supplied in PET bottles as follows:
| 200 mL bottles | NDC 0131-5410-71 |
| 465 mL bottles | NDC 0131-5410-70 |
Suicidal Thinking and Behavior
Patients, their caregivers, and families should be counseled that AEDs, including VIMPAT, may increase the risk of suicidal thoughts and behavior and should be advised of the need to be alert for the emergence or worsening of 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 [
see
Warnings and Precautions (5.1)].
Dizziness and Ataxia
Patients should be counseled that VIMPAT use may cause dizziness, double vision, abnormal coordination and balance, and somnolence. Patients taking VIMPAT should be advised not to drive, operate complex machinery, or engage in other hazardous activities until they have become accustomed to any such effects associated with VIMPAT [
see
Warnings and Precautions (5.2)].
Cardiac Rhythm and Conduction Abnormalities
Patients should be counseled that VIMPAT is associated with electrocardiographic changes that may predispose to irregular beat and syncope, particularly in patients with underlying cardiovascular disease, with heart conduction problems or who are taking other medications that affect the heart. Patients who develop syncope should lay down with raised legs and contact their health care provider [
see
Warnings and Precautions (5.3)].
Drug Reaction with Eosinophilia and Systemic Symptoms (DRESS)/Multi-Organ Hypersensitivity
Patients should be aware that VIMPAT may cause serious hypersensitivity reactions affecting multiple organs such as the liver and kidney. VIMPAT should be discontinued if a serious hypersensitivity reaction is suspected. Patients should also be instructed to report promptly to their physicians any symptoms of liver toxicity (e.g., fatigue, jaundice, dark urine) [
see
Warnings and Precautions (5.6)].
Pregnancy Registry
Advise patients to notify their healthcare provider if they become pregnant or intend to become pregnant during VIMPAT therapy. Encourage patients to enroll in the North American Antiepileptic Drug (NAAED) pregnancy registry if they become pregnant. This registry is collecting information about the safety of AEDs during pregnancy [
see
Use in Specific Populations (8.1)].