"March 4, 2010 -- One of the oldest drugs used to treat the most common form of pediatric epilepsy is also the most effective, a study shows.
As many as 17% of children with epilepsy have absence seizures, also known as petit mal seizure"...
The following adverse reactions are described in more detail in the WARNINGS AND PRECAUTIONS section of the label:
- Serious skin rashes [see WARNINGS AND PRECAUTIONS]
- Multiorgan hypersensitivity reactions and organ failure [see WARNINGS AND PRECAUTIONS]
- Blood dyscrasias [see WARNINGS AND PRECAUTIONS]
- Suicidal behavior and ideation [see WARNINGS AND PRECAUTIONS]
- Aseptic meningitis [see WARNINGS AND PRECAUTIONS]
- Withdrawal seizures [see WARNINGS AND PRECAUTIONS]
- Status epilepticus [see WARNINGS AND PRECAUTIONS]
- Sudden unexplained death in epilepsy [see WARNINGS AND PRECAUTIONS]
Clinical Trial Experience With LAMICTAL XR For Treatment Of Primary Generalized Tonic-Clonic And Partial-Onset Seizures
Most Common Adverse Reactions In Clinical Trials
Adjunctive Therapy in Patients With Epilepsy: 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.
In these 2 trials, adverse reactions led to withdrawal of 4 (2%) patients in the group receiving placebo and 10 (5%) patients in the group receiving LAMICTAL XR. Dizziness was the most common reason for withdrawal in the group receiving LAMICTAL XR (5 patients [3%]). The next most common adverse reactions leading to withdrawal in 2 patients each (1%) were rash, headache, nausea, and nystagmus.
Table 4 displays the incidence of adverse reactions in these two 19-week, double-blind, placebo-controlled trials of patients with PGTC and partial onset seizures.
Table 4: Adverse Reactions in Pooled,
Placebo-Controlled, Adjunctive Trials in Patients With Epilepsya
|Percent of Patients Receiving Adjunctive LAMICTAL XR
(n = 190)
|Percent of Patients Receiving Adjunctive Placebo
(n = 195)
|Ear and labyrinth disorders|
|General disorders and administration site conditions|
|Asthenia and fatigue||6||4|
|Infections and infestations|
|Metabolic and nutritional disorders|
|Musculoskeletal and connective tissue disorder|
|Tremor and intention tremor||6||1|
|Cerebellar coordination and balance disorder||3||0|
|Respiratory, thoracic, and mediastinal disorders|
|aAdverse reactions that occurred in at least 2% of patients treated with LAMICTAL XR and at a greater incidence than placebo.|
Note: In these trials the incidence of nonserious rash was 2% for LAMICTAL XR and 3% for placebo. In clinical trials evaluating immediate-release lamotrigine, the rate of serious rash was 0.3% in adults on adjunctive therapy for epilepsy [see BOXED WARNING].
Adverse reactions were also analyzed to assess the incidence of the onset of an event in the titration period, and in the maintenance period, and if adverse reactions occurring in the titration phase persisted in the maintenance phase.
The incidence for many adverse reactions caused by treatment with LAMICTAL XR was increased relative to placebo (i.e., treatment difference between LAMICTAL XR and placebo ≥ 2%) in either the titration or maintenance phases of the trial. During the titration phase, an increased incidence (shown in descending order of % treatment difference) was observed for diarrhea, nausea, vomiting, somnolence, vertigo, myalgia, hot flush, and anxiety. During the maintenance phase, an increased incidence was observed for dizziness, tremor, and diplopia. Some adverse reactions developing in the titration phase were notable for persisting ( > 7 days) into the maintenance phase. These persistent adverse reactions included somnolence and dizziness.
There were inadequate data to evaluate the effect of dose and/or concentration on the incidence of adverse reactions because, although patients were randomized to different target doses based upon concomitant AEDs, the plasma exposure was expected to be generally similar among all patients receiving different doses. However, in a randomized, parallel trial comparing placebo with 300 and 500 mg/day of immediate-release lamotrigine, the incidence of the most common adverse reactions ( ≥ 5%) such as ataxia, blurred vision, diplopia, and dizziness were dose related. Less common adverse reactions ( < 5%) were not assessed for dose-response relationships.
Monotherapy in Patients With Epilepsy: Adverse reactions observed in this trial were generally similar to those observed and attributed to drug in adjunctive and monotherapy immediate-release lamotrigine and adjunctive LAMICTAL XR placebo-controlled trials. Only 2 adverse events, nasopharyngitis and upper respiratory tract infection, were observed at a rate of ≥ 3% and not reported at a similar rate in previous trials. Because this trial did not include a placebo control group, causality could not be established [see Clinical Studies].
Other Adverse Reactions Observed During The Clinical Development Of Immediate-Release Lamotrigine
All reported reactions are included except those already listed in the previous tables or elsewhere in the labeling, those too general to be informative, and those not reasonably associated with the use of the drug.
Adjunctive Therapy in Adults With Epilepsy
In addition to the adverse reactions reported above from the development of LAMICTAL XR, the following adverse reactions with an uncertain relationship to lamotrigine were reported during the clinical development of immediate-release lamotrigine for treatment of epilepsy in adults. These reactions occurred in ≥ 2% of patients receiving immediate-release lamotrigine and more frequently than in the placebo group.
Body as a Whole: Headache, flu syndrome, fever, neck pain.
Respiratory: Pharyngitis, cough increased.
Skin and Appendages: Rash, pruritus.
Monotherapy in Adults With Epilepsy
In addition to the adverse reactions reported above from the development of LAMICTAL XR, the following adverse reactions with an uncertain relationship to lamotrigine were reported during the clinical development of immediate-release lamotrigine for treatment of epilepsy in adults. These reactions occurred in > 2% of patients receiving immediate-release lamotrigine and more frequently than in the placebo group.
Body as a Whole: Chest pain.
Metabolic and Nutritional: Weight decrease, peripheral edema.
Nervous: Hypesthesia, libido increase, decreased reflexes.
Skin and Appendages: Contact dermatitis, dry skin, sweating.
Special Senses: Vision abnormality.
Urogenital (female patients only): Dysmenorrhea.
Other Clinical Trial Experience
Immediate-release lamotrigine has been administered to 6,694 individuals for whom complete adverse reaction data was captured during all clinical trials, only some of which were placebo controlled.
Adverse reactions are further classified within body system categories and enumerated in order of decreasing frequency using the following definitions: frequent adverse reactions are defined as those occurring in at least 1/100 patients; Infrequent adverse reactions are those occurring in 1/100 to 1/1,000 patients; rare adverse reactions are those occurring in fewer than 1/1,000 patients.
Hematologic and Lymphatic System: Infrequent: Ecchymosis, leukopenia. Rare: Anemia, eosinophilia, fibrin decrease, fibrinogen decrease, iron deficiency anemia, leukocytosis, lymphocytosis, macrocytic anemia, petechia, thrombocytopenia.
Metabolic and Nutritional Disorders: Infrequent: Aspartate transaminase increased. Rare: Alcohol intolerance, alkaline phosphatase increase, alanine transaminase increase, bilirubinemia, gamma glutamyl transpeptidase increase, hyperglycemia.
Musculoskeletal System: Rare: Muscle atrophy, pathological fracture, tendinous contracture.
Nervous System: Frequent: Confusion.
Infrequent: Akathisia, apathy, aphasia, depersonalization, dysarthria, dyskinesia, euphoria, hallucinations, hostility, hyperkinesia, hypertonia, libido decreased, memory decrease, mind racing, movement disorder, myoclonus, panic attack, paranoid reaction, personality disorder, psychosis, stupor. Rare: Choreoathetosis, delirium, delusions, dysphoria, dystonia, extrapyramidal syndrome, hemiplegia, hyperalgesia, hyperesthesia, hypokinesia, hypotonia, manic depression reaction, neuralgia, paralysis, peripheral neuritis.
Respiratory System: Rare: Hiccup, hyperventilation.
Special Senses: Frequent: Amblyopia. Infrequent: Abnormality of accommodation, conjunctivitis, dry eyes, ear pain, photophobia, taste perversion, tinnitus. Rare: Deafness, lacrimation disorder, oscillopsia, parosmia, ptosis, strabismus, taste loss, uveitis, visual field defect.
Urogenital System: Infrequent: Abnormal ejaculation, hematuria, impotence, menorrhagia, polyuria, urinary incontinence. Rare: Acute kidney failure, breast neoplasm, creatinine increase, female lactation, kidney failure, kidney pain, nocturia, urinary retention, urinary urgency.
Postmarketing Experience With Immediate-Release Lamotrigine
The following adverse events (not listed above in clinical trials or other sections of the prescribing information) have been identified during postapproval use of immediate-release lamotrigine. Because these events are reported voluntarily from a population of uncertain size, it is not always possible to reliably estimate their frequency or establish a causal relationship to drug exposure.
Blood and Lymphatic
Hepatobiliary Tract and Pancreas
Rhabdomyolysis has been observed in patients experiencing hypersensitivity reactions.
Aggression, exacerbation of Parkinsonian symptoms in patients with pre-existing Parkinson's disease, tics.
Read the Lamictal XR (lamotrigine extended-release tablets) Side Effects Center for a complete guide to possible side effects
Significant drug interactions with lamotrigine are summarized in this section. Additional details of these drug interaction studies, which were conducted using immediate-release lamotrigine, are provided in the Clinical Pharmacology section [see CLINICAL PHARMACOLOGY].
Table 5: Established and Other Potentially Significant
|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
|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%.|
|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.|
|↓= Decreased (induces lamotrigine glucuronidation).
↑= Increased (inhibits lamotrigine glucuronidation).
? = Conflicting data.
Effect of LAMICTAL XR on Organic Cationic Transporter 2 Substrates
Lamotrigine is an inhibitor of renal tubular secretion via organic cationic transporter 2 (OCT2) proteins [see CLINICAL PHARMACOLOGY]. This may result in increased plasma levels of certain drugs that are substantially excreted via this route. Coadministration of LAMICTAL XR with OCT2 substrates with a narrow therapeutic index (e.g., dofetilide) is not recommended.
Read the Lamictal XR Drug Interactions Center for a complete guide to possible interactions
Last reviewed on RxList: 4/14/2015
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