Lamictal XR 25mg Tablets
WARNING: Severe skin reactions may happen with this drug. These include Stevens-Johnson syndrome (SJS), toxic epidermal necrolysis (TEN), and other serious reactions. Sometimes, body organs may also be affected. These reactions can be deadly. Get medical help right away if you have signs like red, swollen, blistered, or peeling skin; red or irritated eyes; sores in your mouth, throat, nose, eyes, genitals, or any areas of skin; fever; chills; body aches; shortness of breath; or swollen glands. The chance of a skin reaction is raised in children between 2 and 17 years old. It may also be raised if you take valproic acid or divalproex sodium with this drug, if you start taking this drug at too high of a dose, or if your dose is raised too fast. Skin reactions have also happened without any of these. Talk with your doctor.Most cases of skin reactions have happened within 2 to 8 weeks of starting this drug, but some show up after longer treatment like 6 months. Talk with the doctor.This drug is not approved for use in children younger than 13 years old. Talk with the doctor. @ COMMON USES: It is used to help control certain kinds of seizures.It may be given to you for other reasons. Talk with the doctor.
Drug Class
Anticonvulsant, Mood Stabilizer
Pharmacologic Class
Phenyltriazine derivative, Voltage-gated sodium channel blocker
Pregnancy Category
C
FDA Approved
May 2006
DEA Schedule
Not Controlled
Overview
What is this medicine?
Lamictal XR is an extended-release medication used to treat certain types of seizures (epilepsy) and to help prevent extreme mood swings in adults with bipolar disorder. It works by stabilizing electrical activity in the brain.
How to Use This Medicine
Taking Your Medication Correctly
To get the most benefit from your medication, it's essential to take it exactly as directed by your doctor. Carefully read all the information provided with your prescription, and follow the instructions closely. You can take this medication with or without food.
Continue taking your medication as prescribed by your doctor or healthcare provider, even if you start to feel well. It's crucial to swallow the medication whole, without chewing, breaking, or crushing it. If you have difficulty swallowing, discuss this with your doctor.
Important Safety Precautions
Do not change your dosage or stop taking this medication without consulting your doctor, as this may lead to seizures. If you need to stop taking this medication, your doctor will instruct you on how to gradually taper off the dosage to minimize the risk of side effects. If you do stop taking the medication, you may need to restart at a lower dose and gradually increase the dosage under your doctor's guidance.
Storing and Disposing of Your Medication
To maintain the effectiveness and safety of your medication, store it at room temperature, protected from light, and in a dry place. Avoid storing it in a bathroom. Keep all medications in a secure location, out of the reach of children and pets.
When disposing of unused or expired medication, do not flush it down the toilet or pour it down the drain unless instructed to do so by your pharmacist. Instead, check with your pharmacist for guidance on the best disposal method, or look into local drug take-back programs.
What to Do If You Miss a Dose
If you miss a dose, take it as soon as you remember. However, if it's close to the time for your next scheduled dose, skip the missed dose and resume your regular dosing schedule. Do not take two doses at the same time or take extra doses to make up for the missed one.
To get the most benefit from your medication, it's essential to take it exactly as directed by your doctor. Carefully read all the information provided with your prescription, and follow the instructions closely. You can take this medication with or without food.
Continue taking your medication as prescribed by your doctor or healthcare provider, even if you start to feel well. It's crucial to swallow the medication whole, without chewing, breaking, or crushing it. If you have difficulty swallowing, discuss this with your doctor.
Important Safety Precautions
Do not change your dosage or stop taking this medication without consulting your doctor, as this may lead to seizures. If you need to stop taking this medication, your doctor will instruct you on how to gradually taper off the dosage to minimize the risk of side effects. If you do stop taking the medication, you may need to restart at a lower dose and gradually increase the dosage under your doctor's guidance.
Storing and Disposing of Your Medication
To maintain the effectiveness and safety of your medication, store it at room temperature, protected from light, and in a dry place. Avoid storing it in a bathroom. Keep all medications in a secure location, out of the reach of children and pets.
When disposing of unused or expired medication, do not flush it down the toilet or pour it down the drain unless instructed to do so by your pharmacist. Instead, check with your pharmacist for guidance on the best disposal method, or look into local drug take-back programs.
What to Do If You Miss a Dose
If you miss a dose, take it as soon as you remember. However, if it's close to the time for your next scheduled dose, skip the missed dose and resume your regular dosing schedule. Do not take two doses at the same time or take extra doses to make up for the missed one.
Lifestyle & Tips
- Take Lamictal XR exactly as prescribed, usually once daily. Do not chew, crush, or divide the tablet; swallow it whole.
- Do not stop taking this medication suddenly, as it can cause serious problems, including increased seizures. Any dose changes should be made slowly under your doctor's supervision.
- Be aware of the risk of serious skin rash. Contact your doctor immediately if you develop any rash, fever, swollen glands, or facial swelling.
- Avoid or limit alcohol consumption, as it can increase side effects like dizziness or drowsiness.
- This medication can cause dizziness or drowsiness, especially when starting treatment. Be careful when driving or operating machinery until you know how it affects you.
- If you are taking birth control pills, tell your doctor, as Lamictal XR can make them less effective, and birth control pills can affect Lamictal XR levels. You may need a higher dose of Lamictal XR or a different birth control method.
- Carry a medical alert card or wear medical identification stating that you take lamotrigine.
Available Forms & Alternatives
Available Strengths:
- Lamictal 150mg Tablets
- Lamictal 200mg Tablets
- Lamictal 100mg Tablets
- Lamictal 25mg Tablets
- Lamictal 5mg Chewabl Disprsbl Tabs
- Lamictal 25mg Chewabl Disprsbl Tabs
- Lamictal Orange Strt Kit25mg/100mg
- Lamictal Blue Starter Kit 25mg
- Lamictal XR 25mg Tablets
- Lamictal XR 50mg Tablets
- Lamictal XR 100mg Tablets
- Lamictal XR 200mg Tablets
- Lamictal XR 25-50-100mg Titrtn Kit
- Lamictal XR 25-50mg Titration Kt 28
- Lamictal XR 50-100-200mg Titrtn Kit
- Lamictal ODT 25mg Tablets
- Lamictal ODT 50mg Tablets
- Lamictal ODT 100mg Tablets
- Lamictal ODT 200mg Tablets
- Lamictal ODT 25-50-100mg Tb Kt Orng
- Lamictal ODT 25-50mg Tb Kit Blue
- Lamictal ODT 50-100mg Tb Kit Green
- Lamictal Green Strt Kit 25mg/100mg
- Lamictal XR 300mg Tablets
- Lamictal XR 250mg Tablets
Generic Alternatives:
Dosing & Administration
Adult Dosing
Standard Dose:
Highly variable, depends on concomitant medications and indication. For epilepsy (adjunctive therapy) without enzyme-inducing AEDs or valproate: Initial 25 mg once daily for 2 weeks, then 50 mg once daily for 2 weeks, then 100 mg once daily for 1 week, then 150 mg once daily for 1 week, then 200 mg once daily. Further increases to maintenance of 300-500 mg/day.
Dose Range:
25 - 500 mg
Condition-Specific Dosing:
epilepsy_adjunctive_therapy_no_inducers_or_valproate:
Initial 25 mg once daily for 2 weeks, then 50 mg once daily for 2 weeks, then 100 mg once daily for 1 week, then 150 mg once daily for 1 week, then 200 mg once daily. Maintenance 300-500 mg/day.
epilepsy_adjunctive_therapy_with_valproate:
Initial 25 mg every other day for 2 weeks, then 25 mg once daily for 2 weeks, then 50 mg once daily for 1 week, then 75 mg once daily for 1 week, then 100 mg once daily. Maintenance 100-200 mg/day.
epilepsy_adjunctive_therapy_with_enzyme_inducing_aeds_without_valproate:
Initial 50 mg once daily for 2 weeks, then 100 mg once daily for 2 weeks, then 200 mg once daily for 1 week, then 300 mg once daily for 1 week, then 400 mg once daily. Maintenance 400-600 mg/day.
bipolar_disorder_no_inducers_or_valproate:
Initial 25 mg once daily for 2 weeks, then 50 mg once daily for 2 weeks, then 100 mg once daily for 1 week, then 200 mg once daily. Maintenance 200 mg/day (can be increased to 400 mg/day if needed).
bipolar_disorder_with_valproate:
Initial 25 mg every other day for 2 weeks, then 25 mg once daily for 2 weeks, then 50 mg once daily for 1 week, then 100 mg once daily. Maintenance 100 mg/day.
bipolar_disorder_with_enzyme_inducing_aeds_without_valproate:
Initial 50 mg once daily for 2 weeks, then 100 mg once daily for 2 weeks, then 200 mg once daily for 1 week, then 300 mg once daily for 1 week, then 400 mg once daily. Maintenance 400 mg/day.
Pediatric Dosing
Neonatal:
Not established
Infant:
Not established
Child:
Not established for Lamictal XR below 13 years of age for epilepsy. Not established for bipolar disorder in pediatric patients.
Adolescent:
For epilepsy (adjunctive therapy) in patients 13 years and older, dosing is similar to adults. Not established for bipolar disorder in pediatric patients.
Dose Adjustments
Renal Impairment:
Mild:
No specific adjustment recommended, but monitor for adverse effects.
Moderate:
No specific adjustment recommended, but monitor for adverse effects.
Severe:
Consider a reduction in maintenance dose by 25% for patients with significant renal impairment (CrCl < 30 mL/min). Monitor for adverse effects.
Dialysis:
Supplemental doses after dialysis are generally not required as lamotrigine is minimally dialyzable. Monitor for adverse effects.
Hepatic Impairment:
Mild:
No specific adjustment recommended.
Moderate:
Consider a reduction in initial, escalation, and maintenance doses by 25%.
Severe:
Consider a reduction in initial, escalation, and maintenance doses by 50%. Monitor for adverse effects.
Pharmacology
Mechanism of Action
Lamotrigine is a phenyltriazine derivative that is thought to stabilize neuronal membranes and modulate presynaptic glutamate and aspartate release by inhibiting voltage-sensitive sodium channels. This action prevents repetitive firing of action potentials and reduces the pathological release of excitatory amino acids.
Pharmacokinetics
Absorption:
Bioavailability:
Approximately 98%
Tmax:
Approximately 4-12 hours (for XR formulation, can be up to 18 hours)
FoodEffect:
Food does not significantly affect the rate or extent of absorption of Lamictal XR.
Distribution:
Vd:
Approximately 0.9-1.3 L/kg
ProteinBinding:
Approximately 55%
CnssPenetration:
Yes
Elimination:
HalfLife:
Highly variable: approximately 25-33 hours (monotherapy), 13-15 hours (with enzyme inducers), 48-59 hours (with valproate), 70 hours (with valproate and enzyme inducers).
Clearance:
Approximately 0.3-0.5 mL/min/kg (monotherapy)
ExcretionRoute:
Renal (approximately 94% as metabolites, 2% as unchanged drug)
Unchanged:
Approximately 2%
Pharmacodynamics
OnsetOfAction:
Gradual, due to slow titration to minimize rash risk. Therapeutic effects may take several weeks.
PeakEffect:
Not directly applicable due to slow titration and chronic use. Steady-state concentrations are achieved after several weeks of stable dosing.
DurationOfAction:
Extended-release formulation provides once-daily dosing, maintaining therapeutic levels over 24 hours.
Safety & Warnings
BLACK BOX WARNING
Serious Skin Rashes: Life-threatening serious rashes, including Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN), have been reported in patients receiving lamotrigine. The incidence of these rashes, which have resulted in hospitalization and rare deaths, is approximately 0.3% to 0.8% in pediatric patients (aged 2 to 16 years) and 0.08% to 0.3% in adults. The risk of serious rash is increased by coadministration with valproate, exceeding the recommended initial dose, or exceeding the recommended dose escalation. Benign rashes are also common, but it is not possible to predict which rashes will prove to be serious. Lamotrigine should 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.
Side Effects
Serious Side Effects: Seek Medical Help Immediately
Although rare, some people may experience severe and potentially life-threatening side effects while taking this medication. If you notice any of the following symptoms, contact your doctor or seek medical attention right away:
Signs of an allergic reaction, such as:
+ Rash or hives
+ Itching or red, swollen, blistered, or peeling skin (with or without fever)
+ Wheezing or tightness in the chest or throat
+ Difficulty breathing, swallowing, or talking
+ Unusual hoarseness or swelling of the mouth, face, lips, tongue, or throat
Signs of kidney problems, including:
+ Inability to urinate or changes in urine output
+ Blood in the urine or significant weight gain
Signs of liver problems, such as:
+ Dark urine
+ Fatigue or decreased appetite
+ Upset stomach or stomach pain
+ Light-colored stools or vomiting
+ Yellow skin or eyes
Shortness of breath, significant weight gain, or swelling in the arms or legs
Severe muscle pain or weakness
Severe joint pain or swelling
Changes in vision
Chest pain or pressure
Abnormal heartbeat (fast, slow, or irregular)
Severe dizziness or fainting
Changes in balance or coordination
Inability to control eye movements
Flu-like symptoms
Painful or irregular menstrual periods
Low blood cell counts, which can increase the risk of:
+ Infections (fever, chills, or sore throat)
+ Bleeding problems (unexplained bruising or bleeding)
+ Anemia (feeling extremely tired or weak)
Additionally, an immune system problem called hemophagocytic lymphohistiocytosis (HLH) has been reported with this medication. HLH can be life-threatening. Seek medical help immediately if you experience:
Fever
Swollen glands
Rash
Seizures
Confusion or decreased alertness
Changes in balance or trouble walking (new or worsening symptoms)
Other Possible Side Effects
Most people taking this medication will not experience serious side effects, but some may encounter mild or moderate side effects. If you experience any of the following symptoms, contact your doctor or seek medical attention if they bother you or persist:
Dizziness, drowsiness, fatigue, or weakness
Constipation, diarrhea, stomach pain, upset stomach, vomiting, or decreased appetite
Shakiness or tremors
Difficulty sleeping
Nose or throat irritation
Weight loss
Dry mouth
* Back pain
This is not an exhaustive list of possible side effects. If you have questions or concerns about side effects, consult your doctor. You can also report side effects to the FDA at 1-800-332-1088 or online at https://www.fda.gov/medwatch.
Although rare, some people may experience severe and potentially life-threatening side effects while taking this medication. If you notice any of the following symptoms, contact your doctor or seek medical attention right away:
Signs of an allergic reaction, such as:
+ Rash or hives
+ Itching or red, swollen, blistered, or peeling skin (with or without fever)
+ Wheezing or tightness in the chest or throat
+ Difficulty breathing, swallowing, or talking
+ Unusual hoarseness or swelling of the mouth, face, lips, tongue, or throat
Signs of kidney problems, including:
+ Inability to urinate or changes in urine output
+ Blood in the urine or significant weight gain
Signs of liver problems, such as:
+ Dark urine
+ Fatigue or decreased appetite
+ Upset stomach or stomach pain
+ Light-colored stools or vomiting
+ Yellow skin or eyes
Shortness of breath, significant weight gain, or swelling in the arms or legs
Severe muscle pain or weakness
Severe joint pain or swelling
Changes in vision
Chest pain or pressure
Abnormal heartbeat (fast, slow, or irregular)
Severe dizziness or fainting
Changes in balance or coordination
Inability to control eye movements
Flu-like symptoms
Painful or irregular menstrual periods
Low blood cell counts, which can increase the risk of:
+ Infections (fever, chills, or sore throat)
+ Bleeding problems (unexplained bruising or bleeding)
+ Anemia (feeling extremely tired or weak)
Additionally, an immune system problem called hemophagocytic lymphohistiocytosis (HLH) has been reported with this medication. HLH can be life-threatening. Seek medical help immediately if you experience:
Fever
Swollen glands
Rash
Seizures
Confusion or decreased alertness
Changes in balance or trouble walking (new or worsening symptoms)
Other Possible Side Effects
Most people taking this medication will not experience serious side effects, but some may encounter mild or moderate side effects. If you experience any of the following symptoms, contact your doctor or seek medical attention if they bother you or persist:
Dizziness, drowsiness, fatigue, or weakness
Constipation, diarrhea, stomach pain, upset stomach, vomiting, or decreased appetite
Shakiness or tremors
Difficulty sleeping
Nose or throat irritation
Weight loss
Dry mouth
* Back pain
This is not an exhaustive list of possible side effects. If you have questions or concerns about side effects, consult your doctor. You can also report side effects to the FDA at 1-800-332-1088 or online at https://www.fda.gov/medwatch.
Seek Immediate Medical Attention If You Experience:
- Any new skin rash (especially if blistering, widespread, or accompanied by fever)
- Fever, chills, or sore throat
- Swollen lymph nodes or glands
- Swelling of the face, eyes, or lips
- Unusual bruising or bleeding
- Yellowing of the skin or eyes (jaundice)
- Dark urine or pale stools
- Severe muscle pain or weakness
- Worsening of seizures
- New or worsening depression, anxiety, agitation, or suicidal thoughts/behaviors
- Severe dizziness or loss of coordination
- Blurred or double vision
Before Using This Medicine
Before Taking This Medication: Important Information to Share with Your Doctor
It is essential to inform your doctor about the following:
Any allergies you have, including allergies to this medication, its components, or other substances, such as foods or drugs. Be sure to describe the allergic reaction you experienced, including any symptoms that occurred.
If you are currently taking dofetilide, as this may interact with the medication.
To ensure your safety, it is crucial to provide your doctor and pharmacist with a comprehensive list of:
All prescription and over-the-counter (OTC) medications you are taking
Any natural products or vitamins you are using
* Your health problems, as these may affect the safety and efficacy of the medication
Before making any changes to your medication regimen, including starting, stopping, or adjusting the dose of any drug, consult with your doctor to confirm that it is safe to do so. This will help prevent potential interactions and ensure the safe use of this medication.
It is essential to inform your doctor about the following:
Any allergies you have, including allergies to this medication, its components, or other substances, such as foods or drugs. Be sure to describe the allergic reaction you experienced, including any symptoms that occurred.
If you are currently taking dofetilide, as this may interact with the medication.
To ensure your safety, it is crucial to provide your doctor and pharmacist with a comprehensive list of:
All prescription and over-the-counter (OTC) medications you are taking
Any natural products or vitamins you are using
* Your health problems, as these may affect the safety and efficacy of the medication
Before making any changes to your medication regimen, including starting, stopping, or adjusting the dose of any drug, consult with your doctor to confirm that it is safe to do so. This will help prevent potential interactions and ensure the safe use of this medication.
Precautions & Cautions
Important Warnings and Cautions
When taking this medication, it is essential to inform all your healthcare providers, including doctors, nurses, pharmacists, and dentists, about your treatment. This will help ensure your safety and prevent potential interactions with other medications.
Caution with Daily Activities
Avoid driving and engaging in activities that require alertness until you understand how this medication affects you. It may take several weeks to experience the full effects of the medication.
Monitoring and Lab Tests
Regular blood tests will be necessary, as directed by your doctor. Be sure to discuss any concerns or questions with your doctor. Additionally, inform all your healthcare providers and laboratory personnel that you are taking this medication, as it may affect certain lab test results.
Interactions with Other Substances
Before consuming alcohol, marijuana, or other forms of cannabis, or taking prescription or over-the-counter medications that may cause drowsiness, consult with your doctor.
Mental Health and Suicidal Thoughts
Like other medications used to treat seizures, this drug may rarely increase the risk of suicidal thoughts or actions, particularly in individuals with a history of suicidal behavior. If you experience new or worsening symptoms such as depression, anxiety, restlessness, irritability, panic attacks, or mood changes, contact your doctor immediately. If you have suicidal thoughts or actions, seek medical attention right away.
Risk of Aseptic Meningitis
This medication may increase the risk of a severe brain problem called aseptic meningitis. If you experience symptoms such as headache, fever, chills, severe nausea or vomiting, stiff neck, rash, sensitivity to light, drowsiness, or confusion, contact your doctor immediately.
Medication Verification
Always verify that you have the correct medication, as some drugs may have similar names or appearances. If you notice any changes in the medication's shape, color, size, or labeling, consult with your pharmacist.
Heart Problems
If you have a history of abnormal heartbeat, heart failure, or other heart problems, discuss the risks with your doctor. Abnormal heartbeats can increase the risk of sudden death in individuals with certain heart conditions.
Pediatric Use
When used in children, this medication requires careful monitoring, as the risk of certain side effects may be higher in this population.
Birth Control and Hormone Interactions
Birth control pills and other hormone-based birth control methods may affect the levels of this medication in your body. Consult with your doctor before starting or stopping any hormone-based birth control. The risk of side effects may be increased during the week when birth control pills are not active. Additionally, birth control pills and other hormone-based methods may be less effective in preventing pregnancy when taking this medication. Consider using an alternative birth control method, such as a condom.
Pregnancy and Breastfeeding
If you are pregnant, plan to become pregnant, or are breastfeeding, discuss the benefits and risks of this medication with your doctor.
Seizure Management
If your seizures change or worsen after starting this medication, consult with your doctor to adjust your treatment plan as needed.
When taking this medication, it is essential to inform all your healthcare providers, including doctors, nurses, pharmacists, and dentists, about your treatment. This will help ensure your safety and prevent potential interactions with other medications.
Caution with Daily Activities
Avoid driving and engaging in activities that require alertness until you understand how this medication affects you. It may take several weeks to experience the full effects of the medication.
Monitoring and Lab Tests
Regular blood tests will be necessary, as directed by your doctor. Be sure to discuss any concerns or questions with your doctor. Additionally, inform all your healthcare providers and laboratory personnel that you are taking this medication, as it may affect certain lab test results.
Interactions with Other Substances
Before consuming alcohol, marijuana, or other forms of cannabis, or taking prescription or over-the-counter medications that may cause drowsiness, consult with your doctor.
Mental Health and Suicidal Thoughts
Like other medications used to treat seizures, this drug may rarely increase the risk of suicidal thoughts or actions, particularly in individuals with a history of suicidal behavior. If you experience new or worsening symptoms such as depression, anxiety, restlessness, irritability, panic attacks, or mood changes, contact your doctor immediately. If you have suicidal thoughts or actions, seek medical attention right away.
Risk of Aseptic Meningitis
This medication may increase the risk of a severe brain problem called aseptic meningitis. If you experience symptoms such as headache, fever, chills, severe nausea or vomiting, stiff neck, rash, sensitivity to light, drowsiness, or confusion, contact your doctor immediately.
Medication Verification
Always verify that you have the correct medication, as some drugs may have similar names or appearances. If you notice any changes in the medication's shape, color, size, or labeling, consult with your pharmacist.
Heart Problems
If you have a history of abnormal heartbeat, heart failure, or other heart problems, discuss the risks with your doctor. Abnormal heartbeats can increase the risk of sudden death in individuals with certain heart conditions.
Pediatric Use
When used in children, this medication requires careful monitoring, as the risk of certain side effects may be higher in this population.
Birth Control and Hormone Interactions
Birth control pills and other hormone-based birth control methods may affect the levels of this medication in your body. Consult with your doctor before starting or stopping any hormone-based birth control. The risk of side effects may be increased during the week when birth control pills are not active. Additionally, birth control pills and other hormone-based methods may be less effective in preventing pregnancy when taking this medication. Consider using an alternative birth control method, such as a condom.
Pregnancy and Breastfeeding
If you are pregnant, plan to become pregnant, or are breastfeeding, discuss the benefits and risks of this medication with your doctor.
Seizure Management
If your seizures change or worsen after starting this medication, consult with your doctor to adjust your treatment plan as needed.
Overdose Information
Overdose Symptoms:
- Nystagmus (involuntary eye movements)
- Ataxia (loss of coordination)
- Dizziness
- Drowsiness
- Headache
- Nausea
- Vomiting
- Coma
- Generalized convulsions (seizures)
- Intraventricular conduction delay (cardiac effects)
What to Do:
Seek immediate medical attention. Call 911 or Poison Control at 1-800-222-1222. There is no specific antidote; treatment is supportive.
Drug Interactions
Major Interactions
- Valproate (valproic acid, divalproex sodium): Significantly increases lamotrigine levels (by ~2-fold) due to inhibition of glucuronidation, requiring a significant reduction in lamotrigine dose.
- Carbamazepine, Phenytoin, Phenobarbital, Primidone, Rifampin: Significantly decrease lamotrigine levels (by ~40-50%) due to induction of glucuronidation, requiring an increase in lamotrigine dose.
- Estrogen-containing oral contraceptives: Decrease lamotrigine levels (by ~50%) due to induction of glucuronidation, requiring an increase in lamotrigine dose. Breakthrough bleeding may occur with lamotrigine initiation or dose changes.
- Lopinavir/ritonavir, Atazanavir/ritonavir: Decrease lamotrigine levels, requiring an increase in lamotrigine dose.
- Dofetilide: Lamotrigine may increase dofetilide levels, increasing risk of QT prolongation. Co-administration generally not recommended.
Moderate Interactions
- Risperidone: Lamotrigine may decrease risperidone levels.
- Olanzapine: Lamotrigine may decrease olanzapine levels.
- Aripiprazole: Lamotrigine may decrease aripiprazole levels.
- Paroxetine, Sertraline: May slightly decrease lamotrigine levels.
- Topiramate: Co-administration may increase risk of rash or other adverse effects, but generally no significant pharmacokinetic interaction.
Minor Interactions
- Acetaminophen: May slightly decrease lamotrigine levels with chronic high-dose use.
Monitoring
Baseline Monitoring
Complete Blood Count (CBC) with differential
Rationale: To establish baseline and monitor for rare but serious hematologic reactions (e.g., aplastic anemia, agranulocytosis).
Timing: Prior to initiation
Liver function tests (LFTs)
Rationale: To establish baseline and monitor for rare but serious hepatic dysfunction.
Timing: Prior to initiation
Renal function tests (e.g., creatinine, BUN)
Rationale: To establish baseline and guide dose adjustments in severe renal impairment.
Timing: Prior to initiation
Skin examination
Rationale: To establish baseline and educate patient on recognizing rash.
Timing: Prior to initiation
Routine Monitoring
Clinical assessment for rash (e.g., Stevens-Johnson Syndrome, Toxic Epidermal Necrolysis)
Frequency: Daily during titration, then regularly
Target: Absence of rash
Action Threshold: Any new rash, especially if accompanied by fever, lymphadenopathy, or facial swelling, requires immediate discontinuation and medical evaluation.
Seizure frequency/severity (for epilepsy)
Frequency: Regularly, at each follow-up visit
Target: Reduction in seizure frequency or complete seizure control
Action Threshold: Worsening seizures or inadequate control may require dose adjustment or alternative therapy.
Mood stabilization (for bipolar disorder)
Frequency: Regularly, at each follow-up visit
Target: Stabilization of mood, reduction in mood episodes
Action Threshold: Worsening mood symptoms or inadequate control may require dose adjustment or alternative therapy.
Signs/symptoms of hypersensitivity syndrome (DRESS)
Frequency: Regularly, especially during first 8 weeks
Target: Absence of symptoms
Action Threshold: Fever, rash, lymphadenopathy, facial swelling, organ involvement (e.g., hepatitis, nephritis) require immediate discontinuation and medical evaluation.
Suicidal ideation/behavior
Frequency: Regularly, especially during initial treatment and dose changes
Target: Absence of suicidal thoughts or behaviors
Action Threshold: Any new or worsening suicidal thoughts or behaviors require immediate clinical assessment and intervention.
Drug levels (therapeutic drug monitoring)
Frequency: Not routinely recommended, but may be considered in cases of suspected non-adherence, drug interactions, renal/hepatic impairment, or treatment failure.
Target: Not well-established for efficacy, but generally 2.5-15 mcg/mL for epilepsy. Levels vary widely based on indication and individual response.
Action Threshold: Levels outside expected range for given dose, or clinical signs of toxicity/inefficacy.
Symptom Monitoring
- Skin rash (any type, especially blistering or widespread)
- Fever
- Swollen lymph glands (lymphadenopathy)
- Facial swelling
- Sore throat
- Mouth sores
- Unusual bruising or bleeding
- Yellowing of skin or eyes (jaundice)
- Dark urine
- Severe muscle pain
- Unexplained weakness or fatigue
- Worsening of seizures
- Changes in mood or behavior (e.g., new or worsening depression, anxiety, agitation, suicidal thoughts)
- Coordination problems
- Dizziness
- Blurred or double vision
Special Patient Groups
Pregnancy
Lamotrigine is classified as Pregnancy Category C. It should be used during pregnancy only if the potential benefit justifies the potential risk to the fetus. Data from pregnancy registries suggest that lamotrigine monotherapy is associated with a low risk of major congenital malformations, but a small increased risk of oral clefts has been observed in some studies (though not consistently). Folic acid supplementation is generally recommended for women of childbearing potential taking antiepileptic drugs.
Trimester-Specific Risks:
First Trimester:
Potential for increased risk of oral clefts (cleft lip/palate) based on some, but not all, studies. Risk is generally considered low compared to other AEDs.
Second Trimester:
Not specifically associated with unique risks in the second trimester.
Third Trimester:
Not specifically associated with unique risks in the third trimester. Monitor for potential withdrawal symptoms in the neonate if exposure continues until birth.
Lactation
Lamotrigine is excreted into breast milk. The amount varies, but infant serum concentrations can be significant. Monitor breastfed infants for adverse effects such as rash, drowsiness, poor feeding, and apnea. Weigh the benefits of breastfeeding against the potential risks to the infant. Some experts suggest monitoring infant lamotrigine levels if concerns arise.
Infant Risk:
L3 (Moderately Safe) - Monitor infant for adverse effects. Risk of rash, drowsiness, poor feeding, and apnea.
Pediatric Use
Lamictal XR is approved as adjunctive therapy for partial-onset seizures in patients 13 years and older. It is not approved for use in pediatric patients younger than 13 years for epilepsy, nor for bipolar disorder in any pediatric age group. The risk of serious rash is higher in pediatric patients (0.3-0.8%) compared to adults (0.08-0.3%).
Geriatric Use
Use with caution in elderly patients. Start with lower doses and titrate slowly, as elderly patients may be more sensitive to the adverse effects (e.g., dizziness, ataxia). Renal and hepatic function should be considered.
Clinical Information
Clinical Pearls
- The most critical aspect of lamotrigine therapy is the slow titration schedule to minimize the risk of serious skin rash (SJS/TEN). Adherence to the recommended titration is paramount.
- Patients must be educated to report any rash immediately, as well as other signs of hypersensitivity syndrome (fever, lymphadenopathy, facial swelling).
- Drug interactions are significant, especially with valproate (increases lamotrigine levels) and enzyme-inducing AEDs/oral contraceptives (decrease lamotrigine levels). Dosing adjustments are required.
- Lamictal XR is a once-daily formulation that must be swallowed whole; it cannot be crushed or chewed.
- While therapeutic drug monitoring is not routinely recommended, it can be useful in cases of suspected non-adherence, significant drug interactions, or unexplained toxicity/lack of efficacy.
- Lamotrigine is often a preferred agent for bipolar depression due to its mood-stabilizing properties without inducing mania.
Alternative Therapies
- Other antiepileptic drugs (AEDs) for epilepsy: Levetiracetam, Carbamazepine, Oxcarbazepine, Valproate, Topiramate, Zonisamide, Gabapentin, Pregabalin, Phenytoin, Phenobarbital.
- Other mood stabilizers for bipolar disorder: Lithium, Valproate, Carbamazepine, Atypical antipsychotics (e.g., Quetiapine, Olanzapine, Lurasidone, Cariprazine).
Cost & Coverage
Average Cost:
Varies widely, typically $100-$300+ per 30 tablets
Generic Available:
Yes
Insurance Coverage:
Tier 2 or Tier 3 (preferred brand or non-preferred brand, depending on plan)
General Drug Facts
If your symptoms or health issues persist or worsen, it is essential to contact your doctor promptly. To ensure safe use, never share your medication with others or take someone else's medication. This medication is accompanied by a Medication Guide, which is a patient fact sheet that provides crucial information. It is vital to read this guide carefully and review it again whenever you receive a refill of this medication. If you have any questions or concerns about this medication, consult with your doctor, pharmacist, or other healthcare provider. In the event of a suspected overdose, immediately call your local poison control center or seek emergency medical attention. When reporting the incident, be prepared to provide details about the medication taken, the quantity, and the time it occurred.