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Lamotrigine
Overview
Forms, strengths and routes
Source: NDC DirectoryRegulatory status
Source: Drugs@FDANDC Directory| Product | Trade name | Form | Strength | Ingredient | Status | TE | Flags |
|---|---|---|---|---|---|---|---|
| 204158-001 | LAMOTRIGINE | TABLET, ORALLY DISINTEGRATING | LAMOTRIGINE | Prescription | AB | ||
| 204158-002 | LAMOTRIGINE | TABLET, ORALLY DISINTEGRATING | LAMOTRIGINE | Prescription | AB | ||
| 204158-003 | LAMOTRIGINE | TABLET, ORALLY DISINTEGRATING | LAMOTRIGINE | Prescription | AB | ||
| 204158-004 | LAMOTRIGINE | TABLET, ORALLY DISINTEGRATING | LAMOTRIGINE | Prescription | AB |
Therapeutic equivalence
Source: Orange BookWhat this rating means: Therapeutically equivalent — bioequivalence demonstrated by in vivo or in vitro testing
Codes beginning with “A” indicate products the FDA considers therapeutically equivalent. Codes beginning with “B” indicate bioequivalence has not been established. See methodology.
Approval history
Source: Drugs@FDA| Type | No. | Action | Status | Date | Review |
|---|---|---|---|---|---|
| Supplement | 13 | Labeling | Approved | June 26, 2026 | Standard |
| Supplement | 11 | Labeling | Approved | June 26, 2026 | Standard |
| Supplement | 8 | Labeling | Approved | June 26, 2026 | Standard |
| Supplement | 7 | Labeling | Approved | June 26, 2026 | Standard |
| Supplement | 4 | Labeling | Approved | February 12, 2020 | Standard |
| Supplement | 3 | Labeling | Approved | February 12, 2020 | Standard |
| Supplement | 2 | Labeling | Approved | February 12, 2020 | Standard |
| Original application | 1 | Approved | October 27, 2015 | — |
Prescribing information
Source: openFDA Drug LabelingReproduced verbatim from the Structured Product Labeling submitted to the FDA (effective 20260422). This is the manufacturer's labelling text, not a summary and not advice.
Boxed Warning
openFDA Drug LabelingWARNING: SERIOUS SKIN RASHES WARNING: SERIOUS SKIN RASHES See full prescribing information for complete boxed warning. Cases of life-threatening serious rashes, including Stevens-Johnson syndrome and toxic epidermal necrolysis, and/or rash-related death have been caused by lamotrigine. The rate of serious rash is greater in pediatric patients than in adults. Additional factors that may increase the risk of rash include: coadministration with valproate. exceeding recommended initial dose of lamotrigine tablets. exceeding recommended dose escalation for lamotrigine tablets. presence of the HLA-B*1502 allele. (5.1) Benign rashes are also caused by lamotrigine; however, it is not possible to predict which rashes will prove to be serious or life threatening. Lamotrigine tablets should be discontinued at the first sign of rash, unless the rash is clearly not drug related. (5.1) Lamotrigine tablets can cause serious rashes requiring hospitalization and discontinuation of treatment. The incidence of these rashes, which have included Stevens-Johnson syndrome, is approximately 0.3% to 0.8% in pediatric patients (aged 2 to 17 years) and 0.08% to 0.3% in adults receiving lamotrigine tablets. One rash-related death was reported in a prospectively followed cohort of 1,983 pediatric patients (aged 2 to 16 years) with epilepsy taking lamotrigine tablets as adjunctive therapy. In worldwide postmarketing experience, rare cases of toxic epidermal necrolysis and/or rash-related death have been reported in adult and pediatric patients, but their numbers are too few to permit a precise estimate of the rate. In addition to age, factors that may increase the risk of occurrence or the severity of rash caused by lamotrigine tablets include (1) coadministration of lamotrigine tablets with valproate (includes valproic acid and divalproex sodium), (2) exceeding the recommended initial dose of lamotrigine tablets, (3) exceeding the recommended dose escalation for lamotrigine tablets, or (4) the presence of the HLA-B*1502 allele However, cases have occurred in the absence of these factors. Nearly all cases of life-threatening rashes caused by lamotrigine tablets have occurred within 2 to 8 weeks of treatment initiation. However, isolated cases have occurred after prolonged treatment (e.g., 6 months). Accordingly, duration of therapy cannot be relied upon as means to predict the potential risk heralded by the first appearance of a rash. Although benign rashes are also caused by lamotrigine tablets, it is not possible to predict reliably which rashes will prove to be serious or life threatening. Accordingly, lamotrigine tablets should ordinarily be discontinued at the first sign of rash, unless the rash is clearly not drug related. Discontinuation of treatment may not prevent a rash from becoming life threatening or permanently disabling or disfiguring [see Warnings and Precautions ( 5.1 )] .
Recent Major Changes
openFDA Drug LabelingDosage and Administration (2.1, 2.2, 2.4) 4/2025 Warnings and Precautions, Concomitant Use with Estrogen-Containing Products, Including Oral Contraceptives (5.9) 4/2025 Sudden Unexplained Death in Epilepsy (5.12) – removal 4/2025 Boxed Warning 10/2025 Dosage and Administration (2.1, 2.2, 2.4) 4/2025 Warnings and Precautions, Serious Skin Rashes 10/2025 Concomitant Use with Estrogen-Containing Products, Including Oral Contraceptives (5.9) 4/2025 Sudden Unexplained Death in Epilepsy (5.12) – removal 4/2025
Indications and Usage
openFDA Drug Labeling1 INDICATIONS AND USAGE Lamotrigine orally disintegrating tablets are indicated for: Epilepsy—adjunctive therapy in patients aged 2 years and older : partial-onset seizures. primary generalized tonic-clonic (PGTC) seizures. generalized seizures of Lennox-Gastaut syndrome. ( 1.1 ) Epilepsy—monotherapy in patients aged 16 years and older : Conversion to monotherapy in patients with partial-onset seizures who are receiving treatment with carbamazepine, phenytoin, phenobarbital, primidone, or valproate as the single antiepileptic drug. ( 1.1 ) Bipolar disorder : Maintenance treatment of bipolar I disorder to delay the time to occurrence of mood episodes in patients treated for acute mood episodes with standard therapy. ( 1.2 ) Limitations of Use: Treatment of acute manic or mixed episodes is not recommended. Effectiveness of lamotrigine in the acute treatment of mood episodes has not been established. 1.1 Epilepsy Adjunctive Therapy Lamotrigine orally disintegrating tablets are indicated as adjunctive therapy for the following seizure types in patients aged 2 years and older: partial-onset seizures. primary generalized tonic-clonic (PGTC) seizures. generalized seizures of Lennox-Gastaut syndrome. Monotherapy Lamotrigine orally disintegrating tablets are indicated for conversion to monotherapy in adults (aged 16 years and older) with partial-onset seizures who are receiving treatment with carbamazepine, phenytoin, phenobarbital, primidone, or valproate as the single antiepileptic drug (AED). Safety and effectiveness of lamotrigine orally disintegrating tablets have not been established (1) as initial monotherapy; (2) for conversion to monotherapy from AEDs other than carbamazepine, phenytoin, phenobarbital, primidone, or valproate; or (3) for simultaneous conversion to monotherapy from 2 or more concomitant AEDs. 1.2 Bipolar Disorder Lamotrigine orally disintegrating tablets are indicated for the maintenance treatment of bipolar I disorder to delay the time to occurrence of mood episodes (depression, mania, hypomania, mixed episodes) in patients treated for acute mood episodes with standard therapy [see Clinical Studies (14.2) ] . Limitations of Use Treatment of acute manic or mixed episodes is not recommended. Effectiveness of lamotrigine orally disintegrating tablets in the acute treatment of mood episodes has not been established.
Dosage and Administration
openFDA Drug Labeling2 DOSAGE AND ADMINISTRATION Dosing is based on concomitant medications, indication, and patient age. ( 2.1 , 2.2 , 2.3 , 2.4 ) To avoid an increased risk of rash, the recommended initial dose and subsequent dose escalations should not be exceeded. Lamotrigine Tablets Starter Kits are available for the first 5 weeks of treatment. ( 2.1 , 16 ) Do not restart lamotrigine tablets in patients who discontinued due to rash unless the potential benefits clearly outweigh the risks. ( 2.1 , 5.1 ) Adjustments to maintenance doses will be necessary in most patients starting or stopping estrogen-containing products, including oral contraceptives. ( 2.1 , 5.9 ) Discontinuation: Taper over a period of at least 2 weeks (approximately 50% dose reduction per week). ( 2.1 , 5.10 ) Epilepsy: Adjunctive therapy—See Table 1 for patients older than 12 years and Tables 2 and 3 for patients aged 2 to 12 years. ( 2.2 ) Conversion to monotherapy—See Table 4. ( 2.3 ) Bipolar disorder: See Tables 5 and 6 . ( 2.4 ) 2.1 General Dosing Considerations Rash There are suggestions that the risk of severe, potentially life-threatening rash may be increased by (1) coadministration of lamotrigine tablets with valproate, (2) exceeding the recommended initial dose of lamotrigine tablets, or (3) exceeding the recommended dose escalation for lamotrigine tablets. However, cases have occurred in the absence of these factors [see Boxed Warning ]. Therefore, it is important that the dosing recommendations be followed closely. The risk of nonserious rash may be increased when the recommended initial dose and/or the rate of dose escalation for lamotrigine tablets is exceeded and in patients with a history of allergy or rash to other AEDs. Lamotrigine Tablets Starter Kits provide lamotrigine tablets at doses consistent with the recommended titration schedule for the first 5 weeks of treatment, based upon concomitant medications, for patients with epilepsy (older than 12 years) and bipolar I disorder (adults) and are intended to help reduce the potential for rash. The use of Lamotrigine Tablets Starter Kits is recommended for appropriate patients who are starting or restarting lamotrigine tablets [see How Supplied/Storage and Handling ( 16 )] . It is recommended that lamotrigine tablets not be restarted in patients who discontinued due to rash associated with prior treatment with lamotrigine unless the potential benefits clearly outweigh the risks. If the decision is made to restart a patient who has discontinued lamotrigine tablets, the need to restart with the initial dosing recommendations should be assessed. The greater the interval of time since the previous dose, the greater consideration should be given to restarting with the initial dosing recommendations. If a patient has discontinued lamotrigine for a period of more than 5 half-lives, it is recommended that initial dosing recommendations and guidelines be followed. The half-life of lamotrigine is affected by other concomitant medications [see Clinical Pharmacology ( 12.3 )]. Lamotrigine Tablets Added to Drugs Known to Induce or Inhibit Glucuronidation Because lamotrigine is metabolized predominantly by glucuronic acid conjugation, drugs that are known to induce or inhibit glucuronidation may affect the apparent clearance of lamotrigine. Drugs that induce glucuronidation include carbamazepine, phenytoin, phenobarbital, primidone, rifampin, estrogen-containing products, including oral contraceptives, and the protease inhibitors lopinavir/ritonavir and atazanavir/ritonavir. Valproate inhibits glucuronidation. For dosing considerations for lamotrigine tablets in patients on estrogen-containing products, including contraceptives, and atazanavir/ritonavir, see below and Table 13. For dosing considerations for lamotrigine tablets in patients on other drugs known to induce or inhibit glucuronidation, see Tables 1, 2, 5 to 6, and 13. Target Plasma Levels for Patients with Epilepsy or Bipolar Disorder A therapeutic plasma conc …
Dosage Forms and Strengths
openFDA Drug Labeling3 DOSAGE FORMS AND STRENGTHS Orally disintegrating tablets: 25 mg, 50 mg, 100 mg, and 200 mg. ( 3.3 , 16 ) 3.3 Orally Disintegrating Tablets 25-mg, White colored, round shaped, flat-faced, bevel-edged tablets debossed with “NT” on one side and “123” on the other side. 50-mg, White colored, round shaped, flat-faced, bevel-edged tablets debossed with “EP” on one side and “191” on the other side. 100-mg, Peach colored, round shaped, flat-faced, bevel-edged tablets debossed with “E” on one side and “432” on the other side. 200-mg, White colored, round shaped, flat-faced, bevel-edged tablets debossed with “EP” on one side and “433” on the other side.
Contraindications
openFDA Drug Labeling4 CONTRAINDICATIONS Hypersensitivity to the drug or its ingredients. ( Boxed Warning , 4 ) Lamotrigine tablets are contraindicated in patients who have demonstrated hypersensitivity (e.g., rash, angioedema, acute urticaria, extensive pruritus, mucosal ulceration) to the drug or its ingredients [see Boxed Warning, Warnings and Precautions ( 5.1 , 5.3 )] .
Warnings and Cautions
openFDA Drug Labeling5 WARNINGS AND PRECAUTIONS Life-threatening serious rash and/or rash-related death: Discontinue at the first sign of rash, unless the rash is clearly not drug related. ( Boxed Warning , 5.1 ) Hemophagocytic lymphohistiocytosis: Consider this diagnosis and evaluate patients immediately if they develop signs or symptoms of systemic inflammation. Discontinue lamotrigine if an alternative etiology is not established. ( 5.2 ) Fatal or life-threatening hypersensitivity reaction: Multiorgan hypersensitivity reactions, also known as drug reaction with eosinophilia and systemic symptoms, may be fatal or life threatening. Early signs may include rash, fever, and lymphadenopathy. These reactions may be associated with other organ involvement, such as hepatitis, hepatic failure, blood dyscrasias, or acute multiorgan failure. Lamotrigine should be discontinued if alternate etiology for this reaction is not found. ( 5.3 ) Cardiac rhythm and conduction abnormalities: Based on in vitro findings, lamotrigine could cause serious arrhythmias and/or death in patients with certain underlying cardiac disorders or arrhythmias. Any expected or observed benefit of lamotrigine in an individual patient with clinically important structural or functional heart disease must be carefully weighed against the risk for serious arrhythmias and/or death for that patient. (5.4) Blood dyscrasias (e.g., neutropenia, thrombocytopenia, pancytopenia): May occur, either with or without an associated hypersensitivity syndrome. Monitor for signs of anemia, unexpected infection, or bleeding. ( 5.5 ) Suicidal behavior and ideation: Monitor for suicidal thoughts or behaviors. ( 5.6 ) Aseptic meningitis: Monitor for signs of meningitis. ( 5.7 ) Medication errors due to product name confusion: Strongly advise patients to visually inspect tablets to verify the received drug is correct. ( 5.8 , 16 , 17 ) 5.1 Serious Skin Rashes [see Boxed Warning] Pediatric Population The incidence of serious rash associated with hospitalization and discontinuation of lamotrigine in a prospectively followed cohort of pediatric patients (aged 2 to 17 years) is approximately 0.3% to 0.8%. One rash-related death was reported in a prospectively followed cohort of 1,983 pediatric patients (aged 2 to 16 years) with epilepsy taking lamotrigine as adjunctive therapy. Additionally, there have been rare cases of toxic epidermal necrolysis (TEN) with and without permanent sequelae and/or death in U.S. and foreign postmarketing experience. There is evidence that the inclusion of valproate in a multidrug regimen increases the risk of serious, potentially life-threatening rash in pediatric patients. In pediatric patients who used valproate concomitantly for epilepsy, 1.2% (6 of 482) experienced a serious rash compared with 0.6% (6 of 952) patients not taking valproate. Adult Population Serious rash associated with hospitalization and discontinuation of lamotrigine occurred in 0.3% (11 of 3,348) of adult patients who received lamotrigine in premarketing clinical trials of epilepsy. In the bipolar and other mood disorders clinical trials, the rate of serious rash was 0.08% (1 of 1,233) of adult patients who received lamotrigine as initial monotherapy and 0.13% (2 of 1,538) of adult patients who received lamotrigine as adjunctive therapy. No fatalities occurred among these individuals. However, in worldwide postmarketing experience, rare cases of rash-related death have been reported, but their numbers are too few to permit a precise estimate of the rate. Among the rashes leading to hospitalization were Stevens-Johnson syndrome, toxic epidermal necrolysis, angioedema, and those associated with multi-organ hypersensitivity [ see Warnings and Precautions ( 5.3 )]. Risk Factors Concomitant Use of Valproate There is evidence that the inclusion of valproate in a multidrug regimen increases the risk of serious, potentially life-threatening rash in adults. Specifically, of 584 patients administered lamotrigine with va …
Adverse Reactions
openFDA Drug Labeling6 ADVERSE REACTIONS Epilepsy: Most common adverse reactions (incidence ≥10%) in adults were dizziness, headache, diplopia, ataxia, nausea, blurred vision, somnolence, rhinitis, pharyngitis, and rash. Additional adverse reactions (incidence ≥10%) reported in children included vomiting, infection, fever, accidental injury, diarrhea, abdominal pain, and tremor. ( 6.1 ) Bipolar disorder: Most common adverse reactions (incidence >5%) in adults were nausea, insomnia, somnolence, back pain, fatigue, rash, rhinitis, abdominal pain, and xerostomia. ( 6.1 ) To report SUSPECTED ADVERSE REACTIONS, contact OWP Pharmaceuticals Inc. at 1-800-273-6729 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch . The following serious adverse reactions are described in more detail in the Warnings and Precautions section of the labeling: Serious Skin Rashes [see Warnings and Precautions ( 5.1 )] Hemophagocytic Lymphohistiocytosis [see Warnings and Precautions ( 5.2 )] Multiorgan Hypersensitivity Reactions and Organ Failure [see Warnings and Precautions ( 5.3 )] Cardiac Rhythm and Conduction Abnormalities [see Warnings and Precautions ( 5.4 )] Blood Dyscrasias [see Warnings and Precautions ( 5.5 )] Suicidal Behavior and Ideation [see Warnings and Precautions ( 5.6 )] Aseptic Meningitis [see Warnings and Precautions ( 5.7 )] Withdrawal Seizures [see Warnings and Precautions ( 5.10 )] Status Epilepticus [see Warnings and Precautions ( 5.11 )] 6.1 Clinical Trial 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 with rates in the clinical trials of another drug and may not reflect the rates observed in practice. Epilepsy Most Common Adverse Reactions in All Clinical Trials: Adjunctive Therapy in Adults with Epilepsy: The most commonly observed (≥5% for lamotrigine tablets and more common on drug than placebo) adverse reactions seen in association with lamotrigine tablets during adjunctive therapy in adults and not seen at an equivalent frequency among placebo-treated patients were: dizziness, ataxia, somnolence, headache, diplopia, blurred vision, nausea, vomiting, and rash. Dizziness, diplopia, ataxia, blurred vision, nausea, and vomiting were dose related. Dizziness, diplopia, ataxia, and blurred vision occurred more commonly in patients receiving carbamazepine with lamotrigine tablets than in patients receiving other AEDs with lamotrigine tablets. Clinical data suggest a higher incidence of rash, including serious rash, in patients receiving concomitant valproate than in patients not receiving valproate [see Warnings and Precautions ( 5.1 )] . Approximately 11% of the 3,378 adult patients who received lamotrigine tablets as adjunctive therapy in premarketing clinical trials discontinued treatment because of an adverse reaction. The adverse reactions most commonly associated with discontinuation were rash (3.0%), dizziness (2.8%), and headache (2.5%). In a dose-response trial in adults, the rate of discontinuation of lamotrigine tablets for dizziness, ataxia, diplopia, blurred vision, nausea, and vomiting was dose related. Monotherapy in Adults with Epilepsy: The most commonly observed (≥5% for lamotrigine tablets and more common on drug than placebo) adverse reactions seen in association with the use of lamotrigine tablets during the monotherapy phase of the controlled trial in adults not seen at an equivalent rate in the control group were vomiting, coordination abnormality, dyspepsia, nausea, dizziness, rhinitis, anxiety, insomnia, infection, pain, weight decrease, chest pain, and dysmenorrhea. The most commonly observed (≥5% for lamotrigine tablets and more common on drug than placebo) adverse reactions associated with the use of lamotrigine tablets during the conversion to monotherapy (add-on) period, not seen at an equivalent frequency among low-dose valproate-treated patients, were dizziness, headache, nausea, asthenia, coordina …
Drug Interactions
openFDA Drug Labeling7 DRUG INTERACTIONS Valproate increases lamotrigine concentrations more than 2-fold. ( 7 , 12.3 ) Carbamazepine, phenytoin, phenobarbital, primidone, and rifampin decrease lamotrigine concentrations by approximately 40%. ( 7 , 12.3 ) Estrogen-containing oral contraceptives decrease lamotrigine concentrations by approximately 50%. ( 7 , 12.3 ) Protease inhibitors lopinavir/ritonavir and atazanavir/lopinavir decrease lamotrigine exposure by approximately 50% and 32%, respectively. ( 7 , 12.3 ) Coadministration with organic cationic transporter 2 substrates with narrow therapeutic index is not recommended ( 7 , 12.3 ) Significant drug interactions with lamotrigine tablets are summarized in this section. Uridine 5 ́-diphospho-glucuronyl transferases (UGT) have been identified as the enzymes responsible for metabolism of lamotrigine. Drugs that induce or inhibit glucuronidation may, therefore, affect the apparent clearance of lamotrigine. Strong or moderate inducers of the cytochrome P450 3A4 (CYP3A4) enzyme, which are also known to induce UGT, may also enhance the metabolism of lamotrigine. Those drugs that have been demonstrated to have a clinically significant impact on lamotrigine metabolism are outlined in Table 13. Specific dosing guidance for these drugs is provided in the Dosage and Administration section, and, for women taking estrogen-containing products, including oral contraceptives, in the Warnings and Precautions section [see Dosage and Administration ( 2.1 ), Warnings and Precautions ( 5.9 )] . Additional details of these drug interaction studies are provided in the Clinical Pharmacology section [see Clinical Pharmacology ( 12.3 )] . Table 13. Established and Other Potentially Significant Drug Interactions ↓= Decreased (induces lamotrigine glucuronidation). ↑= Increased (inhibits lamotrigine glucuronidation). ?= Conflicting data. Concomitant Drug Effect on Concentration of Lamotrigine or Concomitant Drug Clinical Comment Estrogen-containing oral contraceptive preparations containing 30 mcg ethinylestradiol and 150 mcg levonorgestrel ↓ lamotrigine ↓ levonorgestrel Decreased lamotrigine concentrations approximately 50%. Decrease in levonorgestrel component by 19%. Carbamazepine and carbamazepine epoxide ↓ lamotrigine ? carbamazepine epoxide Addition of carbamazepine decreases lamotrigine concentration approximately 40%. May increase carbamazepine epoxide levels. Lopinavir/ritonavir ↓ lamotrigine Decreased lamotrigine concentration approximately 50%. Atazanavir/ritonavir ↓ lamotrigine Decreased lamotrigine AUC approximately 32%. Phenobarbital/primidone ↓ lamotrigine Decreased lamotrigine concentration approximately 40%. Phenytoin ↓ lamotrigine Decreased lamotrigine concentration approximately 40%. Rifampin ↓ lamotrigine Decreased lamotrigine AUC approximately 40%. Valproate ↑ lamotrigine ? valproate Increased lamotrigine concentrations slightly more than 2-fold. There are conflicting study results regarding effect of lamotrigine on valproate concentrations: 1) a mean 25% decrease in valproate concentrations in healthy volunteers, 2) no change in valproate concentrations in controlled clinical trials in patients with epilepsy. Effect of Lamotrigine Tablets on Organic Cationic Transporter 2 Substrates Lamotrigine is an inhibitor of renal tubular secretion via organic cationic transporter 2 (OCT2) proteins [see Clinical Pharmacology ( 12.3 )] . This may result in increased plasma levels of certain drugs that are substantially excreted via this route. Coadministration of lamotrigine tablets with OCT2 substrates with a narrow therapeutic index (e.g., dofetilide) is not recommended.
Use in Specific Populations
openFDA Drug Labeling8 USE IN SPECIFIC POPULATIONS Pregnancy: Based on animal data may cause fetal harm. ( 8.1 ) Hepatic impairment: Dosage adjustments required in patients with moderate and severe liver impairment. ( 2.1 , 8.6 ) Renal impairment: Reduced maintenance doses may be effective for patients with significant renal impairment. ( 2.1 , 8.7 ) 8.1 Pregnancy Pregnancy Exposure Registry There is a pregnancy exposure registry that monitors pregnancy outcomes in women exposed to AEDs, including lamotrigine, during pregnancy. Encourage women who are taking lamotrigine 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 Data from several prospective pregnancy exposure registries and epidemiological studies of pregnant women have not detected an increased frequency of major congenital malformations or a consistent pattern of malformations among women exposed to lamotrigine compared with the general population (see Data) . The majority of lamotrigine pregnancy exposure data are from women with epilepsy. In animal studies, administration of lamotrigine during pregnancy resulted in developmental toxicity (increased mortality, decreased body weight, increased structural variation, neurobehavioral abnormalities) at doses lower than those administered clinically. Lamotrigine decreased fetal folate concentrations in rats, an effect known to be associated with adverse pregnancy outcomes in animals and humans (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. Clinical Considerations Disease-associated Maternal and/or Embryofetal Risk Epilepsy, with or without exposure to antiepileptic drugs, has been associated with several adverse outcomes during pregnancy, including preeclampsia, preterm labor, antepartum and postpartum hemorrhage, placental abruption, poor fetal growth, prematurity, fetal death, and maternal mortality. The risk of maternal or fetal injury may be greatest for patients with untreated or poorly controlled convulsive seizures. Women with epilepsy who become pregnant should not abruptly discontinue antiepileptic drugs, including lamotrigine, due to the risk of status epilepticus or severe seizures, which may be life-threatening [see Warnings and Precautions (5.10)] . Dose Adjustments During Pregnancy and the Postpartum Period As with other AEDs, physiological changes during pregnancy may affect lamotrigine concentrations and/or therapeutic effect. There have been reports of decreased lamotrigine concentrations during pregnancy and restoration of pre-pregnancy concentrations after delivery. Dose adjustments may be necessary to maintain clinical response. Data Human Data: Data from several international pregnancy registries have not shown an increased risk for malformations overall. The International Lamotrigine Pregnancy Registry reported major congenital malformations in 2.2% (95% CI: 1.6%, 3.1%) of 1,558 infants exposed to lamotrigine monotherapy in the first trimester of pregnancy. The NAAED Pregnancy Registry reported major congenital malformations among 2% of 1,562 infants exposed to lamotrigine monotherapy in the first trimester. EURAP, a large international pregnancy registry focused outside of North America, reported major birth defects in 2.9% (95% CI: 2.3%, 3.7%) of 2,514 exposures to lamotrigine monotherapy in the first trimester. The frequency of major congenital malformations was similar to estimates from the general population. The NAAED Pregnancy Registry observed an increased risk of isolated oral clefts: among 2,200 infants exposed to lamotrigine early in pregnancy, the risk of oral clefts was 3.2 per 1,000 (95% CI: 1.4, 6.3), a 3-fold increased risk versus unexposed healthy controls. This finding has not been observed in other large international pregnanc …
Mechanism of Action
openFDA Drug Labeling12.1 Mechanism of Action The precise mechanism(s) by which lamotrigine exerts its anticonvulsant action are unknown. In animal models designed to detect anticonvulsant activity, lamotrigine was effective in preventing seizure spread in the maximum electroshock (MES) and pentylenetetrazol (scMet) tests, and prevented seizures in the visually and electrically evoked after-discharge (EEAD) tests for antiepileptic activity. Lamotrigine also displayed inhibitory properties in the kindling model in rats both during kindling development and in the fully kindled state. The relevance of these models to human epilepsy, however, is not known. One proposed mechanism of action of lamotrigine, the relevance of which remains to be established in humans, involves an effect on sodium channels. In vitro pharmacological studies suggest that lamotrigine inhibits voltage-sensitive sodium channels, thereby stabilizing neuronal membranes and consequently modulating presynaptic transmitter release of excitatory amino acids (e.g., glutamate and aspartate). Effect of Lamotrigine on N-Methyl d-Aspartate-Receptor-Mediated Activity Lamotrigine did not inhibit N-methyl d-aspartate (NMDA)-induced depolarizations in rat cortical slices or NMDA-induced cyclic GMP formation in immature rat cerebellum, nor did lamotrigine displace compounds that are either competitive or noncompetitive ligands at this glutamate receptor complex (CNQX, CGS, TCHP). The IC 50 for lamotrigine effects on NMDA-induced currents (in the presence of 3 μM of glycine) in cultured hippocampal neurons exceeded 100 μM. The mechanisms by which lamotrigine exerts its therapeutic action in bipolar disorder have not been established.
Description
openFDA Drug Labeling11 DESCRIPTION Lamotrigine, USP an AED of the phenyltriazine class, is chemically unrelated to existing AEDs. Lamotrigine’s chemical name is 3,5-diamino-6-(2,3-dichlorophenyl)- as -triazine, its molecular formula is C 9 H 7 N 5 Cl 2 , and its molecular weight is 256.09. Lamotrigine, USP is a white to pale cream-colored powder and has a pK a of 5.7. Lamotrigine, USP is slightly soluble in 0.1 N hydrochloric acid, in acetone, in methanol and in water. The structural formula is: Lamotrigine orally disintegrating tablets are supplied for oral administration. The tablets contain 25 mg (white), 50 mg (white), 100 mg (peach), 200 mg (white) of lamotrigine, USP and the following inactive ingredients: For lamotrigine orally disintegrating tablets 25 mg, 50 mg and 200 mg: Colloidal silicon dioxide, croscarmellose sodium, magnesium stearate, mannitol, starch (maize), microcrystalline cellulose, pregelatinized starch, peppermint flavor, sodium stearyl fumarate and sucralose. For lamotrigine orally disintegrating tablets 100 mg: Colloidal silicon dioxide, croscarmellose sodium, magnesium stearate, mannitol, starch (maize), microcrystalline cellulose, pregelatinized starch, peppermint flavor, sodium stearyl fumarate, sucralose and idacol red oxide of iron. Lamotrigine orally disintegrating tablets are formulated using in-house technologies designed to mask the bitter taste of lamotrigine and achieve a rapid dissolution profile. lamotrigine
Overdosage
openFDA Drug Labeling10 OVERDOSAGE 10.1 Human Overdose Experience Overdoses involving quantities up to 15 g have been reported for lamotrigine, some of which have been fatal. Overdose has resulted in ataxia, nystagmus, seizures (including tonic-clonic seizures), decreased level of consciousness, coma, and intraventricular conduction delay. 10.2 Management of Overdose There are no specific antidotes for lamotrigine. Following a suspected overdose, hospitalization of the patient is advised. General supportive care is indicated, including frequent monitoring of vital signs and close observation of the patient. If indicated, emesis should be induced; usual precautions should be taken to protect the airway. It should be kept in mind that immediate-release lamotrigine is rapidly absorbed [see Clinical Pharmacology ( 12.3 )]. It is uncertain whether hemodialysis is an effective means of removing lamotrigine from the blood. In 6 renal failure patients, about 20% of the amount of lamotrigine in the body was removed by hemodialysis during a 4-hour session. A Poison Control Center should be contacted for information on the management of overdosage of lamotrigine tablets.
How Supplied / Storage and Handling
openFDA Drug Labeling16 HOW SUPPLIED/STORAGE AND HANDLING Lamotrigine Orally Disintegrating Tablets 25-mg, white colored, round shaped, flat-faced, bevel-edged tablets debossed with “NT” on one side and “123” on the other side. Maintenance Packs of 30 (NDC 49884-484-11). 50-mg, white colored, round shaped, flat-faced, bevel-edged tablets debossed with “EP” on one side and “191” on the other side. Maintenance Packs of 30 (NDC 49884-485-11). 100-mg, Peach colored, round shaped, flat-faced, bevel-edged tablets debossed with “E” on one side and “432” on the other side. Maintenance Packs of 30 (NDC 49884-486-11). 200-mg, White colored, round shaped, flat-faced, bevel-edged tablets debossed with “EP” on one side and “433” on the other side. Maintenance Packs of 30 (NDC 49884-487-11). Store at 20° to 25°C (68° to 77°F); with excursions permitted to 15° to 30°C (59° to 86°F). [See USP Controlled Room Temperature]. Lamotrigine Orally Disintegrating Tablets Patient Titration Kit for Patients Taking Valproate (Blue ODT Kit) 25-mg, white colored, round shaped, flat-faced, bevel-edged tablets debossed with “NT” on one side and “123” on the other side and 50 mg, white colored, round shaped, flat-faced, bevel-edged tablets debossed with “EP” on one side and “191” on the other side, blister pack of 28 tablets (21/25-mg tablets and 7/50-mg tablets) (NDC 49884-880-99). Lamotrigine Orally Disintegrating Tablets Patient Titration Kit for Patients Taking Carbamazepine, Phenytoin, Phenobarbital, or Primidone and Not Taking Valproate (Green ODT Kit) 50-mg, white colored, round shaped, flat-faced, bevel-edged tablets debossed with “EP” on one side and “191” on the other side and 100 mg, Peach colored, round shaped, flat-faced, bevel-edged tablets debossed with “E” on one side and “432” on the other side, blister pack of 56 tablets (42/50-mg tablets and 14/100-mg tablets) (NDC 49884-881-99). Lamotrigine Orally Disintegrating Tablets Patient Titration Kit for Patients Not Taking Carbamazepine, Phenytoin, Phenobarbital, Primidone, or Valproate (Orange ODT Kit) 25-mg, white colored, round shaped, flat-faced, bevel-edged tablets debossed with “NT” on one side and “123” on the other side, 50 mg, white colored, round shaped, flat-faced, bevel-edged tablets debossed with “EP” on one side and “191” on the other side, and 100 mg, Peach colored, round shaped, flat-faced, bevel-edged tablets debossed with “E” on one side and “432” on the other side, blister pack of 35 tablets (14/25-mg tablets, 14/50-mg tablets, and 7/100-mg tablets) (NDC 49884-882-99). Store at 20° to 25°C (68° to 77°F); with excursions permitted to 15° to 30°C (59° to 86°F). [See USP Controlled Room Temperature]. Blister Packs If the product is dispensed in a blister pack, the patient should be advised to examine the blister pack before use and not use if blisters are torn, broken, or missing.
Packaging and NDCs
Source: NDC Directory| Package NDC | Product NDC | Labeler | Description | Marketing start |
|---|---|---|---|---|
| 69102-137-10 | 69102-137 | OWP Pharmaceuticals, Inc. | 7 BLISTER PACK in 1 PACKAGE, COMBINATION (69102-137-10) / 1 KIT in 1 BLISTER PACK | August 30, 2017 |
| 69102-359-11 | 69102-359 | OWP Pharmaceuticals, Inc. | 14 BLISTER PACK in 1 PACKAGE, COMBINATION (69102-359-11) / 1 KIT in 1 BLISTER PACK | August 30, 2017 |
| 49884-880-99 | 49884-880 | Par Health USA, LLC | 1 BLISTER PACK in 1 PACKAGE, COMBINATION (49884-880-99) / 1 KIT in 1 BLISTER PACK | December 16, 2015 |
| 49884-881-99 | 49884-881 | Par Health USA, LLC | 1 BLISTER PACK in 1 PACKAGE, COMBINATION (49884-881-99) / 1 KIT in 1 BLISTER PACK | December 16, 2015 |
| 49884-882-99 | 49884-882 | Par Health USA, LLC | 1 BLISTER PACK in 1 PACKAGE, COMBINATION (49884-882-99) / 1 KIT in 1 BLISTER PACK | December 16, 2015 |
| 13668-266-28 | 13668-266 | Torrent Pharmaceuticals Limited | 14 BLISTER PACK in 1 PACKAGE, COMBINATION (13668-266-28) / 1 KIT in 1 BLISTER PACK | January 27, 2009 |
| 13668-266-99 | 13668-266 | Torrent Pharmaceuticals Limited | 7 BLISTER PACK in 1 PACKAGE, COMBINATION (13668-266-99) / 1 KIT in 1 BLISTER PACK | January 27, 2009 |
| 69102-137 | 69102-137 | OWP Pharmaceuticals, Inc. | — | August 30, 2017 |
| 69102-359 | 69102-359 | OWP Pharmaceuticals, Inc. | — | August 30, 2017 |
| 49884-880 | 49884-880 | Par Health USA, LLC | — | November 27, 2015 |
| 49884-881 | 49884-881 | Par Health USA, LLC | — | November 27, 2015 |
| 49884-882 | 49884-882 | Par Health USA, LLC | — | November 27, 2015 |
| 13668-266 | 13668-266 | Torrent Pharmaceuticals Limited | — | January 27, 2009 |
Sources for this page
| Dataset | Agency | Used for |
|---|---|---|
| NDC Directory | FDA | Identity, ingredients, strengths, forms, routes, labelers, packages |
| Drugs@FDA | FDA | Application, sponsor, submissions, review documents, marketing status |
| Orange Book | FDA | Therapeutic equivalence codes, reference drug flags, patents, exclusivity |
| Drug Labeling | FDA / NLM | Prescribing information reproduced above |
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