This article describes possible interactions with lamotrigine oral tablet. Interactions can cause a drug to have a different effect on the body than expected. Interactions can occur due to medications, alcohol, or certain health conditions.
Lamotrigine comes as several types of oral tablets:
- tablets that you swallow
- extended-release (XR) tablets that you swallow*
- orally disintegrating tablets (ODTs), which you allow to dissolve inside your mouth
- tablets for suspension, which may be swallowed, chewed, or dissolved in water or fruit juice and then consumed
* “Extended release (XR)” means the drug slowly releases into your body over time.
Boxed warning: Risk of serious skin rashes
Lamotrigine has a boxed warning for the risk of serious skin rashes. A boxed warning is the most serious warning from the Food and Drug Administration (FDA).
See the end of this article for more information about this warning.
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Other drugs and lamotrigine
The drugs in the list below may interact with lamotrigine oral tablet. This article doesn’t include all drugs that may interact with lamotrigine.
Drug classes or drugs that may interact with lamotrigine oral tablet include:
- estrogen-containing birth control pills
- drug examples: birth control pills that contain 30 mcg ethinyl estradiol and 150 mcg levonorgestrel, such as Iclevia, Introvale, and generic ethinyl estradiol/levonorgestrel tablets
- what might happen: can make lamotrigine and the birth control pill less effective
- the antibiotic rifampin (Rimactane)
- what might happen: can make lamotrigine less effective
- certain antiepileptic drugs
- drug examples: carbamazepine (Tegretol, others), phenytoin (Dilantin)
- what might happen: can make lamotrigine less effective
- dofetilide (Tikosyn)
- what might happen: can increase the effect and risk of side effects of dofetilide
- metformin (Glumetza, others)
- can increase the risk of side effects of metformin
- ritonavir and treatments that contain it
- drug examples: lopinavir/ritonavir (Kaletra), ritonavir (Norvir)
- what might happen: can make lamotrigine less effective
- valproic acid and divalproex sodium
- what might happen: can increase the effect and risk of side effects of lamotrigine; can decrease the effect of valproic acid/divalproex sodium (Depakote)
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Other interactions and lamotrigine
Interactions can occur with supplements, foods, vaccines, and some lab tests. Below you can learn whether lamotrigine oral tablet has these interactions.
The information below doesn’t include all other possible interactions possible with lamotrigine.
Lamotrigine and food
Lamotrigine oral tablet isn’t known to interact with foods. But this doesn’t mean interactions with foods can’t happen or won’t be identified later.
Because of this, talk with your doctor or pharmacist about what foods to avoid when taking lamotrigine oral tablet.
Lamotrigine and supplements
Before taking lamotrigine oral tablet, tell your doctor and pharmacist about any herbs you take, as well as vitamins and supplements. Doing so may help you avoid interactions.
If you have questions about interactions that may affect you, talk with your doctor or pharmacist.
Lamotrigine interactions with herbs
Lamotrigine oral tablet may interact with St. John’s wort. This herb is often used for easing symptoms of depression and improving mood.
Taking lamotrigine and St. John’s wort together may cause lamotrigine to not work as well as expected.
Because of this, ask your doctor or pharmacist before taking St. John’s wort or other herbs while taking lamotrigine oral tablet.
Lamotrigine interactions with vitamins
Lamotrigine oral tablet isn’t known to interact with any vitamins. But this doesn’t mean interactions with vitamins can’t happen or won’t be identified later.
Because of this, ask your doctor or pharmacist before taking any of these products while taking lamotrigine oral tablet.
Lamotrigine and vaccines
Lamotrigine oral tablet isn’t known to interact with any vaccines. But this doesn’t mean interactions with vaccines can’t happen or won’t be identified later.
Because of this, talk with your doctor or pharmacist before receiving any vaccines while taking lamotrigine oral tablet.
Lamotrigine and lab tests
Lamotrigine oral tablet may interact with certain urine drug screening tests.
Taking lamotrigine and having a urine drug test may lead to a false positive for phencyclidine (PCP). This means the test may show a positive result for PCP in your system if you’re taking lamotrigine, even if you haven’t consumed PCP. Lamotrigine doesn’t contain PCP. It’s not exactly clear why lamotrigine may cause this result.
Because of this, talk with your doctor or pharmacist before having any lab tests while taking lamotrigine oral tablet.
Lamotrigine and cannabis or CBD
Studies of cannabis (commonly called marijuana) and cannabis products have been shown to interact with lamotrigine. Cannabidiol (CBD) is an example of a cannabis product.
Taking lamotrigine and using cannabis or a cannabis product may lead to an increased lamotrigine effect and increased risk of side effects lamotrigine may cause.
Before you take lamotrigine oral tablet, tell your doctor and pharmacist if you use cannabis. Doing so may help prevent possible interactions.
Note: Cannabis is illegal at a federal level but is legal in many states to varying degrees.
Alcohol and lamotrigine
Lamotrigine oral tablet isn’t known to interact with alcohol.
However, there are rare reports of alcohol intolerance being a side effect of lamotrigine. Symptoms of alcohol intolerance include fatigue (low energy), low blood pressure, and nausea after consuming alcohol.
If you drink alcohol, talk with your doctor about whether it’s safe to consume it while taking lamotrigine oral tablet. They can provide more information about lamotrigine interactions with alcohol.
Health factors and lamotrigine
Certain medical conditions or other health factors may increase the risk of interactions with lamotrigine oral tablet. Keep in mind that interactions could lead to side effects or affect how well the drug works. Before taking lamotrigine, tell your doctor about your health history. They’ll determine whether lamotrigine is right for you.
Health conditions or other factors that might interact with lamotrigine oral tablet include:
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If you are not in the same household, stay on the phone with them until help arrives.
Questions about lamotrigine and interactions
Here you’ll find answers to some common questions about lamotrigine and possible interactions.
Are there antihistamines that interact with lamotrigine?
No, interactions between antihistamines and lamotrigine haven’t been reported.
A recent study found a possible link between antihistamine drugs, such as diphenhydramine, and new-onset seizures. This is also supported by the Epilepsy Foundation. But these drugs aren’t known to interact with lamotrigine.
Talk with your doctor or pharmacist if you’d like to learn more about antihistamine drugs and possible links to seizures.
Do lamotrigine oral tablets have different interactions than lamotrigine orally disintegrating tablets?
No, different interactions haven’t been reported for lamotrigine oral tablets and lamotrigine orally disintegrating tablets.
These dosage forms do differ in other ways, though. For example, your doctor may prescribe lamotrigine orally disintegrating tablet if you have trouble swallowing pills. This dosage form dissolves in your mouth, and doesn’t have to be swallowed whole.
Talk with your doctor or pharmacist if you’d like to learn more about how different dosage forms of lamotrigine compare.
When to avoid lamotrigine
Certain health conditions or other factors could increase some risks with lamotrigine oral tablet. Because of this, doctors may not prescribe lamotrigine in these cases. These health conditions or other factors are called contraindications.
Before you start taking lamotrigine, tell your doctor about your health history.
A past allergic reaction to lamotrigine has been reported being a contraindication to taking lamotrigine oral tablet.
Before you start taking lamotrigine, tell your doctor if you have a history of allergic reactions to lamotrigine or other seizure medications. They can recommend whether you should take lamotrigine.
Preventing lamotrigine interactions
You may be able to help avoid certain interactions with lamotrigine oral tablet. Before taking this drug, you may want to discuss possible interactions with your doctor and pharmacist.
Things to consider include:
- Whether you drink alcohol or use cannabis.
- Other medications and herbs you take, as well as vitamins and supplements. Your doctor or pharmacist can help you fill out a medication list.
- What to do if you’re prescribed a new drug while using lamotrigine oral tablet.
Taking lamotrigine exactly as prescribed can also help prevent interactions.
What to ask your doctor
If you have questions about lamotrigine and possible interactions, talk with your doctor.
Questions you may want to ask your doctor include:
- How do interactions of lamotrigine compare with levetiracetam (Keppra) or other antiepileptic drugs?
- Does my risk of interactions depend on my dosage of lamotrigine?
- If I take lamotrigine and have certain health conditions, will I be monitored more closely during treatment?
- Should I let you know if I make lifestyle changes, such as to my diet or exercise routine?
Boxed warning for lamotrigine
Lamotrigine has a boxed warning for the risk of serious skin rashes. A boxed warning is the most serious warning from the FDA.
Treatment with lamotrigine may cause a serious or even life threatening skin rash in rare cases. This rash can occur at any time during treatment, but it’s most likely during your first 2–8 weeks of taking lamotrigine. Children may be at higher risk of a serious skin rash compared to adults.
Certain factors may increase the risk of a serious skin rash from taking lamotrigine. These proposed factors include increasing your lamotrigine dose faster than recommended. To lower this risk, your doctor will likely slowly increase your lamotrigine dose over time.
Another factor is taking a higher lamotrigine dose than prescribed by your doctor. Do not take more lamotrigine than prescribed by your doctor. If you have concerns about how well lamotrigine is working to treat your seizures, let your doctor know.
Symptoms of a serious skin rash caused by lamotrigine include blistering or peeling skin and fever. Immediately contact your doctor upon the first symptom of a serious skin rash. They’ll determine whether you should continue taking lamotrigine. If your symptoms feel serious or life threatening, call 911 or seek emergency medical attention.
To learn more, talk with your doctor.
Disclaimer: Optum Perks has made every effort to make certain that all information is factually correct, comprehensive, and up to date. However, this article should not be used as a substitute for the knowledge and expertise of a licensed healthcare professional. You should always consult your doctor or another healthcare professional before taking any medication. The drug information contained herein is subject to change and is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. The absence of warnings or other information for a given drug does not indicate that the drug or drug combination is safe, effective, or appropriate for all patients or all specific uses.
