Lamotrigine 150mg 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. @ COMMON USES: It is used to help control certain kinds of seizures.It is used to treat bipolar disorder.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
Not available
FDA Approved
Dec 1994
DEA Schedule
Not Controlled
Overview
What is this medicine?
Lamotrigine is a medication used to treat certain types of seizures (epilepsy) and to help stabilize mood in people with bipolar disorder. It works by calming overactive nerve signals in the brain. It's very important to take this medicine exactly as prescribed, especially starting with a very low dose and slowly increasing it, to reduce the risk of a serious skin rash.
How to Use This Medicine
Taking Your Medication Correctly
To get the most benefit from your medication, it's essential to follow your doctor's instructions carefully. Read all the information provided to you and follow the instructions closely. You can take this medication with or without food. Continue taking the medication as directed by your doctor or healthcare provider, even if you're feeling well.
Important Administration Instructions
Swallow the medication whole; do not chew, break, or crush it.
If you have difficulty swallowing, consult your doctor for guidance.
Do not alter the dose or stop taking the medication without consulting your doctor, as this may lead to seizures.
If you need to stop taking the medication, your doctor will instruct you on how to gradually taper off the dose to minimize the risk of side effects.
If you've stopped taking the medication, consult your doctor before restarting, as you may need to begin with a lower dose and gradually increase it.
Storing and Disposing of Your Medication
Store the medication at room temperature, protected from light, and in a dry place. Avoid storing it in a bathroom.
Keep all medications in a safe location, out of the reach of children and pets.
Dispose of unused or expired medications properly. Do not flush them down the toilet or pour them down the drain unless instructed to do so by your pharmacist. Check with your pharmacist for guidance on the best disposal method, and consider participating in a local drug take-back program.
What to Do If You Miss a Dose
If you miss a dose, take it as soon as you remember.
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 a missed dose.
To get the most benefit from your medication, it's essential to follow your doctor's instructions carefully. Read all the information provided to you and follow the instructions closely. You can take this medication with or without food. Continue taking the medication as directed by your doctor or healthcare provider, even if you're feeling well.
Important Administration Instructions
Swallow the medication whole; do not chew, break, or crush it.
If you have difficulty swallowing, consult your doctor for guidance.
Do not alter the dose or stop taking the medication without consulting your doctor, as this may lead to seizures.
If you need to stop taking the medication, your doctor will instruct you on how to gradually taper off the dose to minimize the risk of side effects.
If you've stopped taking the medication, consult your doctor before restarting, as you may need to begin with a lower dose and gradually increase it.
Storing and Disposing of Your Medication
Store the medication at room temperature, protected from light, and in a dry place. Avoid storing it in a bathroom.
Keep all medications in a safe location, out of the reach of children and pets.
Dispose of unused or expired medications properly. Do not flush them down the toilet or pour them down the drain unless instructed to do so by your pharmacist. Check with your pharmacist for guidance on the best disposal method, and consider participating in a local drug take-back program.
What to Do If You Miss a Dose
If you miss a dose, take it as soon as you remember.
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 a missed dose.
Lifestyle & Tips
- Take exactly as prescribed; do not stop taking it suddenly without consulting your doctor, as this can cause withdrawal seizures or worsen your condition.
- Do not take more than the prescribed dose or increase the dose faster than instructed, as this significantly increases the risk of a serious rash.
- Report any rash, fever, swollen glands, or facial swelling to your doctor immediately. These could be signs of a serious reaction.
- Avoid activities requiring mental alertness, such as driving or operating machinery, until you know how this medication affects you, as it can cause dizziness or drowsiness.
- If you are taking birth control pills, inform your doctor, as they can affect lamotrigine levels and vice versa. You may need a higher dose of lamotrigine or a different birth control method.
- Avoid alcohol or other CNS depressants, as they can increase drowsiness and dizziness.
- Carry a medical alert card or wear a medical alert bracelet indicating you take lamotrigine, especially if you have epilepsy.
Available Forms & Alternatives
Available Strengths:
- Lamotrigine 150mg Tablets
- Lamotrigine 200mg Tablets
- Lamotrigine 25mg Tablets
- Lamotrigine 100mg Tablets
- Lamotrigine 25mg Chew/disprsbl Tab
- Lamotrigine 5mg Chew/disprsbl Tab
- Lamotrigine ER 50mg Tablets
- Lamotrigine ER 200mg Tablets
- Lamotrigine ER 100mg Tablets
- Lamotrigine 300mg ER Tablets
- Lamotrigine ER 25mg Tablets
- Lamotrigine ODT 25mg Tablets
- Lamotrigine ODT 50mg Tablets
- Lamotrigine Orge Strt Kit25/100mg
- Lamotrigine Blue Starter Kit 25mg T
- Lamotrigine Green Str Kit 25/100mg
- Lamotrigine ODT 100mg Tablets
- Lamotrigine ODT 200mg Tablets
- Lamotrigine ER 250mg Tablets
- Lamotrigine ODT 25-50-100mg Tb Kit
Dosing & Administration
Adult Dosing
Standard Dose:
Highly variable, requires slow titration based on indication and concomitant medications. For monotherapy epilepsy: Initial 25 mg daily for 2 weeks, then 50 mg daily for 2 weeks, then increase by 50 mg/day every 1-2 weeks to maintenance of 100-400 mg/day (divided BID). For bipolar disorder: Initial 25 mg daily for 2 weeks, then 50 mg daily for 2 weeks, then 100 mg daily for 1 week, then 200 mg daily. Further adjustments based on response.
Dose Range:
25 - 700 mg
Condition-Specific Dosing:
Adjunctive therapy with enzyme-inducing AEDs (e.g., carbamazepine, phenytoin, phenobarbital, primidone) without valproate:
Initial 50 mg daily for 2 weeks, then 100 mg daily for 2 weeks, then increase by 100 mg/day every 1-2 weeks. Maintenance 300-500 mg/day (divided BID).
Adjunctive therapy with valproate (with or without other enzyme-inducing AEDs):
Initial 25 mg every other day for 2 weeks, then 25 mg daily for 2 weeks, then increase by 25-50 mg/day every 1-2 weeks. Maintenance 100-200 mg/day (divided BID).
Bipolar Disorder (monotherapy or with non-interacting drugs):
Initial 25 mg daily for 2 weeks, then 50 mg daily for 2 weeks, then 100 mg daily for 1 week, then 200 mg daily. Target maintenance 200 mg/day. Can increase to 400 mg/day if needed.
Pediatric Dosing
Neonatal:
Not established
Infant:
Not established
Child:
Dosing is weight-based and highly dependent on concomitant medications. For adjunctive therapy in children 2-12 years: Initial doses range from 0.3 mg/kg/day to 2 mg/kg/day, titrated slowly over several weeks to maintenance doses ranging from 1-15 mg/kg/day. Max 400 mg/day. Higher risk of rash in this age group.
Adolescent:
Dosing generally follows adult guidelines, with careful titration based on weight and concomitant medications.
Dose Adjustments
Renal Impairment:
Mild:
No specific adjustment needed.
Moderate:
Consider dose reduction in patients with significant renal impairment. Monitor clinical response.
Severe:
Significant dose reduction recommended. For CrCl < 30 mL/min, consider 25-50% reduction in maintenance dose. Monitor closely for adverse effects.
Dialysis:
Lamotrigine is removed by hemodialysis. Supplemental doses may be needed after dialysis. Consult specific guidelines or monitor levels.
Hepatic Impairment:
Mild:
No specific adjustment needed.
Moderate:
Initial, escalation, and maintenance doses should be reduced by approximately 25% for patients with moderate hepatic impairment (Child-Pugh Class B).
Severe:
Initial, escalation, and maintenance doses should be reduced by approximately 50% for patients with severe hepatic impairment (Child-Pugh Class C).
Pharmacology
Mechanism of Action
Lamotrigine is a phenyltriazine derivative that is thought to exert its anticonvulsant and mood-stabilizing effects by blocking voltage-sensitive sodium channels. This action stabilizes neuronal membranes, thereby inhibiting the release of excitatory neurotransmitters (primarily glutamate and aspartate) and preventing repetitive neuronal firing. It also has weak effects on voltage-gated calcium channels and may modulate serotonin receptors.
Pharmacokinetics
Absorption:
Bioavailability:
98%
Tmax:
1.4-4.8 hours (oral)
FoodEffect:
Minimal effect on absorption; can be taken with or without food.
Distribution:
Vd:
0.9-1.3 L/kg
ProteinBinding:
Approximately 55%
CnssPenetration:
Yes
Elimination:
HalfLife:
25-33 hours (monotherapy); significantly affected by concomitant medications (e.g., ~70 hours with valproate, ~13 hours with enzyme inducers)
Clearance:
Approximately 0.3 mL/min/kg (monotherapy)
ExcretionRoute:
Urine (primarily as glucuronide conjugates)
Unchanged:
Approximately 10% (in urine)
Pharmacodynamics
OnsetOfAction:
Gradual (due to slow titration to minimize rash risk); therapeutic effects for seizure control or mood stabilization may take weeks.
PeakEffect:
Not applicable for therapeutic effect due to titration; peak plasma concentration occurs within hours of a single dose.
DurationOfAction:
Dependent on half-life, generally allows for once or twice daily dosing.
Safety & Warnings
BLACK BOX WARNING
Serious Skin Rashes: Lamotrigine can cause serious skin rashes requiring hospitalization and discontinuation of treatment. These include Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN), which can result in permanent disability or death. The incidence of these rashes, which have been reported in both adults and children, is higher in children than in adults. The risk of serious rash is increased by: (1) coadministration with valproate; (2) exceeding the recommended initial dose of lamotrigine; or (3) exceeding the recommended dose escalation for lamotrigine. Benign rashes are also frequent, but it is not possible to predict reliably which rashes will prove to be serious. Therefore, lamotrigine 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.
Side Effects
Serious Side Effects: Seek Medical Help Right Away
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 immediate medical attention:
Signs of an allergic reaction, such as:
+ Rash
+ Hives
+ Itching
+ Red, swollen, blistered, or peeling skin with or without fever
+ Wheezing
+ Tightness in the chest or throat
+ Trouble breathing, swallowing, or talking
+ Unusual hoarseness
+ Swelling of the mouth, face, lips, tongue, or throat
Signs of kidney problems, including:
+ Inability to pass urine
+ Changes in urine output
+ Blood in the urine
+ Sudden weight gain
Signs of liver problems, such as:
+ Dark urine
+ Fatigue
+ Decreased appetite
+ Upset stomach or stomach pain
+ Light-colored stools
+ Vomiting
+ Yellow skin or eyes
Shortness of breath
Sudden weight gain
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
Balance problems
Uncontrolled eye movements
Flu-like symptoms
Painful menstrual periods
Changes in menstrual cycle, including spotting or bleeding between periods
Low Blood Cell Counts
This medication can cause low blood cell counts, which may lead to bleeding problems, infections, or anemia. If you experience any of the following symptoms, contact your doctor right away:
Signs of infection, such as fever, chills, or sore throat
Unexplained bruising or bleeding
Feeling extremely tired or weak
Immune System Problem (Hemophagocytic Lymphohistiocytosis)
In rare cases, this medication can cause a life-threatening immune system problem called hemophagocytic lymphohistiocytosis (HLH). If you experience any of the following symptoms, contact your doctor immediately:
Fever
Swollen glands
Rash
Seizures
Confusion or decreased alertness
Balance problems
Difficulty walking
Other Side Effects
Most people do not experience serious side effects, but some may occur. If you notice any of the following side effects, contact your doctor if they bother you or do not go away:
Dizziness
Drowsiness
Fatigue
Weakness
Constipation
Diarrhea
Stomach pain
Upset stomach
Vomiting
Decreased appetite
Shakiness
Trouble sleeping
Nose or throat irritation
Weight loss
Dry mouth
* Back pain
Reporting Side Effects
If you have questions about side effects or experience any side effects not listed here, contact 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 immediate medical attention:
Signs of an allergic reaction, such as:
+ Rash
+ Hives
+ Itching
+ Red, swollen, blistered, or peeling skin with or without fever
+ Wheezing
+ Tightness in the chest or throat
+ Trouble breathing, swallowing, or talking
+ Unusual hoarseness
+ Swelling of the mouth, face, lips, tongue, or throat
Signs of kidney problems, including:
+ Inability to pass urine
+ Changes in urine output
+ Blood in the urine
+ Sudden weight gain
Signs of liver problems, such as:
+ Dark urine
+ Fatigue
+ Decreased appetite
+ Upset stomach or stomach pain
+ Light-colored stools
+ Vomiting
+ Yellow skin or eyes
Shortness of breath
Sudden weight gain
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
Balance problems
Uncontrolled eye movements
Flu-like symptoms
Painful menstrual periods
Changes in menstrual cycle, including spotting or bleeding between periods
Low Blood Cell Counts
This medication can cause low blood cell counts, which may lead to bleeding problems, infections, or anemia. If you experience any of the following symptoms, contact your doctor right away:
Signs of infection, such as fever, chills, or sore throat
Unexplained bruising or bleeding
Feeling extremely tired or weak
Immune System Problem (Hemophagocytic Lymphohistiocytosis)
In rare cases, this medication can cause a life-threatening immune system problem called hemophagocytic lymphohistiocytosis (HLH). If you experience any of the following symptoms, contact your doctor immediately:
Fever
Swollen glands
Rash
Seizures
Confusion or decreased alertness
Balance problems
Difficulty walking
Other Side Effects
Most people do not experience serious side effects, but some may occur. If you notice any of the following side effects, contact your doctor if they bother you or do not go away:
Dizziness
Drowsiness
Fatigue
Weakness
Constipation
Diarrhea
Stomach pain
Upset stomach
Vomiting
Decreased appetite
Shakiness
Trouble sleeping
Nose or throat irritation
Weight loss
Dry mouth
* Back pain
Reporting Side Effects
If you have questions about side effects or experience any side effects not listed here, contact 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 or worsening skin rash (especially if it spreads, blisters, or is accompanied by fever, sore throat, or swollen glands)
- Fever
- Swollen lymph nodes
- Swelling of the face, eyes, or lips
- Sore throat or mouth sores
- Unusual bruising or bleeding
- Yellowing of the skin or eyes (jaundice)
- Dark urine
- Severe fatigue or weakness
- New or worsening depression, anxiety, or agitation
- Thoughts of self-harm or suicide
- Changes in vision (blurred or double vision)
- Severe dizziness or loss of coordination
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 symptoms you experienced as a result of the allergy.
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 existing health problems
This information will help your doctor determine whether it is safe for you to take this medication in conjunction with your other medications and health conditions. Never start, stop, or adjust the dosage of any medication without first consulting your doctor to confirm that it is safe to do so.
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 symptoms you experienced as a result of the allergy.
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 existing health problems
This information will help your doctor determine whether it is safe for you to take this medication in conjunction with your other medications and health conditions. Never start, stop, or adjust the dosage of any medication without first consulting your doctor to confirm that it is safe to do so.
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, that you are using this drug.
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 drug.
Monitoring and Lab Tests
Regular blood work is necessary, as directed by your doctor. Be sure to discuss any concerns with your doctor. Additionally, inform all your healthcare providers and lab 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 (OTC) medications that may cause drowsiness, consult with your doctor.
Mental Health and Suicidal Thoughts
Like other seizure medications, this drug may rarely increase the risk of suicidal thoughts or actions, particularly in individuals with a history of suicidal thoughts or behaviors. Immediately contact your doctor if you experience any new or worsening symptoms, such as depression, anxiety, restlessness, irritability, panic attacks, or mood changes. 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. Seek medical attention immediately if you experience symptoms such as headache, fever, chills, severe nausea or vomiting, stiff neck, rash, sensitivity to light, drowsiness, or confusion.
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 an 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 using this medication in children, exercise caution, 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. Use an alternative form of birth control, such as a condom, to minimize the risk of pregnancy.
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, that you are using this drug.
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 drug.
Monitoring and Lab Tests
Regular blood work is necessary, as directed by your doctor. Be sure to discuss any concerns with your doctor. Additionally, inform all your healthcare providers and lab 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 (OTC) medications that may cause drowsiness, consult with your doctor.
Mental Health and Suicidal Thoughts
Like other seizure medications, this drug may rarely increase the risk of suicidal thoughts or actions, particularly in individuals with a history of suicidal thoughts or behaviors. Immediately contact your doctor if you experience any new or worsening symptoms, such as depression, anxiety, restlessness, irritability, panic attacks, or mood changes. 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. Seek medical attention immediately if you experience symptoms such as headache, fever, chills, severe nausea or vomiting, stiff neck, rash, sensitivity to light, drowsiness, or confusion.
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 an 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 using this medication in children, exercise caution, 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. Use an alternative form of birth control, such as a condom, to minimize the risk of pregnancy.
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:
- Severe dizziness or unsteadiness
- Blurred or double vision
- Loss of consciousness
- Increased seizures
- Coma
- Cardiac conduction abnormalities (e.g., QRS prolongation)
What to Do:
Seek immediate medical attention. Call 911 or your local poison control center (e.g., 1-800-222-1222 in the US).
Drug Interactions
Major Interactions
- Valproate (increases lamotrigine levels, increases risk of serious rash)
- Estrogen-containing oral contraceptives (decreases lamotrigine levels)
- Rifampin (decreases lamotrigine levels)
- Lopinavir/Ritonavir (decreases lamotrigine levels)
- Atazanavir/Ritonavir (decreases lamotrigine levels)
- Carbamazepine, Phenytoin, Phenobarbital, Primidone (decrease lamotrigine levels)
Moderate Interactions
- Paracetamol/Acetaminophen (high doses may decrease lamotrigine levels)
- Risperidone (lamotrigine may decrease risperidone levels)
- Olanzapine (lamotrigine may decrease olanzapine levels)
- Aripiprazole (lamotrigine may decrease aripiprazole levels)
Minor Interactions
- Folic acid (may slightly decrease lamotrigine levels)
Monitoring
Baseline Monitoring
Complete Blood Count (CBC)
Rationale: To establish baseline and monitor for rare blood dyscrasias (e.g., neutropenia, aplastic anemia).
Timing: Prior to initiation
Liver Function Tests (LFTs)
Rationale: To establish baseline and monitor for rare hepatic dysfunction.
Timing: Prior to initiation
Renal Function (Cr, BUN)
Rationale: To establish baseline, especially if impairment is suspected, as dose adjustments may be needed.
Timing: Prior to initiation
Routine Monitoring
Clinical response (seizure frequency/severity, mood stability)
Frequency: Regularly during titration and maintenance
Target: Individualized
Action Threshold: Worsening symptoms, lack of efficacy, or intolerable side effects
Adverse effects (especially rash, fever, lymphadenopathy, facial swelling, signs of hypersensitivity)
Frequency: Daily during titration, then regularly
Target: Absence of severe adverse effects
Action Threshold: Appearance of rash (especially severe or widespread), fever, or other signs of hypersensitivity; requires immediate medical evaluation and potential discontinuation.
Suicidal ideation/behavior
Frequency: Regularly, especially during initial therapy or dose changes
Target: Absence of suicidal thoughts or behaviors
Action Threshold: Any new or worsening suicidal thoughts or behaviors; requires immediate clinical assessment.
Plasma lamotrigine levels
Frequency: Not routinely recommended, but can be useful in specific situations (e.g., suspected toxicity, non-response, drug interactions, pregnancy, renal/hepatic impairment)
Target: Therapeutic range for epilepsy: 3-14 mcg/mL (varies by lab and clinical context)
Action Threshold: Levels outside therapeutic range or inconsistent with clinical picture; requires dose adjustment or investigation of adherence/interactions.
Symptom Monitoring
- Skin rash (any type, especially widespread, blistering, or painful)
- Fever
- Swollen lymph nodes
- Facial swelling
- Sore throat
- Mouth sores
- Unusual bruising or bleeding
- Yellowing of skin or eyes (jaundice)
- Dark urine
- Severe fatigue
- Worsening seizures
- Changes in mood or behavior (e.g., depression, anxiety, agitation, suicidal thoughts)
- Coordination problems
- Dizziness
- Blurred or double vision
Special Patient Groups
Pregnancy
Lamotrigine is generally considered one of the safer antiepileptic drugs during pregnancy, but use should be carefully weighed against the risks of uncontrolled seizures. Data from pregnancy registries suggest a low risk of major congenital malformations, with some conflicting data regarding oral clefts (overall risk appears low, especially with monotherapy). Dose adjustments may be needed during pregnancy due to changes in lamotrigine clearance.
Trimester-Specific Risks:
First Trimester:
Potential for increased risk of oral clefts (though data is mixed and overall risk appears low, especially with monotherapy). Close monitoring of lamotrigine levels is recommended as clearance may increase.
Second Trimester:
Clearance of lamotrigine may continue to increase, potentially requiring dose adjustments to maintain therapeutic levels.
Third Trimester:
Clearance of lamotrigine may continue to increase. Monitor levels and adjust dose as needed. Monitor neonate for potential withdrawal symptoms or adverse effects.
Lactation
Lamotrigine is excreted into breast milk in significant amounts. While many infants remain asymptomatic, monitor breastfed infants for adverse effects such as rash, sedation, poor feeding, and apnea. Weigh the benefits of breastfeeding against potential infant exposure. Therapeutic drug monitoring in the infant may be considered.
Infant Risk:
L3 (Moderately Safe) - Monitor infant for rash, sedation, poor feeding, and apnea. Risk of adverse effects is generally low but present.
Pediatric Use
Higher incidence of serious rash (SJS/TEN) in children compared to adults, especially those under 16 years of age. Dosing is weight-based and requires careful, slow titration. Not recommended for children under 2 years of age for epilepsy or under 18 years for bipolar disorder.
Geriatric Use
Start with lower doses and titrate slowly due to potential for decreased renal/hepatic function and increased sensitivity to adverse effects. Monitor for dizziness, ataxia, and cognitive side effects.
Clinical Information
Clinical Pearls
- The most critical aspect of lamotrigine therapy is the slow titration schedule to minimize the risk of serious skin rash. Adherence to this schedule is paramount.
- Patients should be educated to report any rash immediately, regardless of appearance, and to discontinue the drug only under medical supervision.
- Concomitant medications, especially valproate and enzyme-inducing AEDs (carbamazepine, phenytoin), significantly alter lamotrigine's pharmacokinetics and necessitate specific dosing adjustments.
- Estrogen-containing oral contraceptives can significantly reduce lamotrigine levels, potentially leading to loss of seizure control or mood stabilization. Patients should be advised of this interaction.
- Lamotrigine is effective for both focal and generalized seizures, including Lennox-Gastaut syndrome. It is also a first-line mood stabilizer for bipolar depression.
- While therapeutic drug monitoring is not routinely recommended, it can be very useful in cases of suspected non-adherence, drug interactions, pregnancy, or renal/hepatic impairment.
Alternative Therapies
- For Epilepsy: Levetiracetam, Carbamazepine, Valproate, Topiramate, Oxcarbazepine, Zonisamide, Phenytoin, Gabapentin, Pregabalin.
- For Bipolar Disorder (Mood Stabilization): Lithium, Valproate, Carbamazepine, Quetiapine, Olanzapine, Lurasidone, Cariprazine.
Cost & Coverage
Average Cost:
Varies widely, typically $20-$100+ per 30 tablets (150mg generic)
Generic Available:
Yes
Insurance Coverage:
Tier 1 or Tier 2 (generic)
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 valuable resource for patients. Please 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, we encourage you to discuss them 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 detailed information, including the substance taken, the amount, and the time it occurred.