Lamictal (lamotrigine) is a prescription drug that’s used to treat bipolar disorder and epilepsy. This drug can interact with other medications. For example, Lamictal can interact with the antibiotic drug rifampin (Rifadin, Rimactane).
Lamictal is used to treat:
- bipolar I disorder in adults
- epilepsy in adults and certain children
Lamictal comes as an oral tablet, a chewable tablet, and a tablet that dissolves on your tongue. It also comes as an extended-release* oral tablet called Lamictal XR.
An interaction can occur because one substance causes another substance to have a different effect than expected. Interactions can also occur if you have certain health conditions.
Keep reading to learn about Lamictal’s possible interactions. And for more information about Lamictal, including details about its uses, see this article.
* Extended release means the drug is slowly released into your body over a long period of time.
Before you start taking Lamictal, tell your doctor and pharmacist about any prescription, over-the-counter, or other drugs you take. Sharing this information with them may help prevent possible interactions. (To learn whether Lamictal interacts with supplements, herbs, and vitamins, see the “Are there other interactions with Lamictal?” section below.)
If you have questions about drug interactions that may affect you, talk with your doctor or pharmacist.
The table below lists drugs that may interact with Lamictal. Keep in mind that this table does not include all drugs that may interact with Lamictal. For more information about some of these interactions, see the “Drug interactions explained” section below.
Drug group or drug name | Drug examples | What can happen |
certain antivirals | • lopinavir/ritonavir (Kaletra) • atazanavir (Reyataz) • ritonavir (Norvir) | Lamictal may be less effective |
certain seizure drugs | • divalproex sodium (Depakote, Depakote ER) • valproate • valproic acid • phenytoin (Dilantin, Phenytek) • carbamazepine (Carbatrol, Epitol, others) | Lamictal may be less effective or have an increased risk of side effects* |
rifampin (Rifadin, Rimactane) | — | Lamictal may be less effective |
certain types of birth control pills | • ethinyl estradiol/levonorgestrel (Seasonale, Seasonique, others) • ethinyl estradiol/desogestrel (Enskyce, Kariva, others) | Lamictal and the birth control pills may be less effective, or you may have a higher risk of side effects from Lamictal |
dofetilide (Tikosyn) | — | increased risk of side effects from dofetilide |
metformin (Fortamet, Glumetza) | — | increased risk of side effects from metformin |
alprazolam (Xanax, Xanax XR) | — | increased risk of side effects from Lamictal and alprazolam |
* To learn more about Lamictal’s side effects, see this article
Certain health conditions or other factors could raise your risk of harm if you take Lamictal. In such cases, your doctor may not prescribe Lamictal for you. These are known as contraindications. The list below includes Lamictal (lamotrigine) contraindications.
If you’ve had an allergic reaction. If you have had an allergic reaction to Lamictal or any of its ingredients, your doctor likely won’t prescribe Lamictal. This is because taking the drug could cause another allergic reaction. You can ask your doctor about other treatments that may be better options for you.
Before you start taking Lamictal, talk with your doctor if any of the factors above apply to you. Your doctor can determine whether Lamictal is safe for you to take.
Lamictal is not known to interact with alcohol. But in rare cases, drinking alcohol while taking Lamictal can lead to alcohol intolerance. With this condition, your digestive system cannot break down alcohol as it should. This may cause symptoms such as nausea, hives, and skin discoloration.
If you have questions about consuming alcohol during your Lamictal treatment, talk with your doctor or pharmacist.
Learn more about certain drug interactions that can occur with Lamictal.
Interaction with rifampin
Lamictal can interact with rifampin (Rifadin, Rimactane), which is an antibiotic used to treat tuberculosis (TB).
What could happen
Taking Lamictal with rifampin may cause your body to break down Lamictal faster than it should. This can lower the level of Lamictal in your body, which could make the drug less effective.
What you can do
Before taking Lamictal, tell your doctor if you take rifampin. They can determine whether it’s safe to take these medications together.
If your doctor prescribes Lamictal with rifampin, they may prescribe a higher dosage* of Lamictal than usual. This helps make sure the drug’s level is high enough in your system to treat your condition.
If you have questions about taking Lamictal with rifampin, talk with your doctor or pharmacist.
* To learn more about Lamictal’s dosage, see this article
Interaction with certain types of birth control pills
Lamictal can interact with birth control pills that contain certain active drugs. (An active drug is what makes a medication work.) These active drugs include estrogens, such as ethinyl estradiol and levonorgestrel (a type of progesterone hormone).
What could happen
Taking Lamictal with birth control pills that contain ethinyl estradiol can make Lamictal less effective. This is because ethinyl estradiol can cause your body to break down Lamictal faster than usual. This can lead to low levels of Lamictal in your system, making Lamictal less effective.
Also, most birth control pills have a “placebo week” in which the pills contain no active drugs. During this week, the level of Lamictal in your body may rise or even double by the end of the week. This sudden change in the drug’s levels can raise your risk of side effects from Lamictal.
In addition, taking Lamictal with birth control pills that contain levonorgestrel may make the birth control less effective. This is because the combination may lower the level of levonorgestrel in your system.
What you can do
Before taking Lamictal, tell your doctor if you take birth control pills. They can determine whether the birth control may interact with Lamictal.
If you take Lamictal with birth control pills that contain estrogen (ethinyl estradiol), your doctor may prescribe a higher dosage of Lamictal. This will help the drug reach a level in your body that’s high enough to treat your condition. (To learn more about Lamictal’s dosage, see this article.)
However, if you develop increased side effects during the placebo week, your doctor may instead recommend switching to a different birth control option, such as a nonhormonal method.
Talk with your doctor or pharmacist if you have questions about taking Lamictal with birth control pills that contain estrogen, levonorgestrel, or both.
Interaction with alprazolam
Lamictal can interact with alprazolam (Xanax, Xanax XR). This drug is a benzodiazepine used to treat anxiety.
What could happen
Taking Lamictal with alprazolam can raise your risk of certain side effects from either drug. Examples include dizziness and problems with balance or coordination. This is because Lamictal and alprazolam can both cause these side effects, so taking them together can raise your risk of these side effects even more.
What you can do
Before taking Lamictal, be sure your doctor knows if you’re taking alprazolam. They can determine whether it’s safe to take Lamictal with this drug.
If you do take Lamictal with alprazolam, watch for dizziness and problems with balance or coordination. If you have these side effects, your doctor can tell you whether it’s safe to keep taking these medications together.
If you have questions about taking Lamictal with alprazolam, talk with your doctor or pharmacist.
Lamictal may have other interactions. They could occur with supplements, foods, vaccines, or even lab tests. See below for details. Note that the information below does not include all other possible interactions with Lamictal.
Does Lamictal interact with supplements?
Before you start taking Lamictal, talk with your doctor and pharmacist about any supplements, herbs, and vitamins you take. Sharing this information with them may help you avoid possible interactions.
If you have questions about interactions that may affect you, talk with your doctor or pharmacist.
Lamictal and herbs
There are currently no reports of Lamictal or Lamictal XR interacting with herbs. But this doesn’t mean that interactions with herbs won’t be recognized in the future.
For this reason, it’s still important to check with your doctor or pharmacist before taking any of these products while taking Lamictal.
Lamictal and vitamins
There are currently no reports of Lamictal or Lamictal XR interacting with vitamins. But this doesn’t mean that vitamin interactions won’t be recognized in the future.
For this reason, it’s still important to check with your doctor or pharmacist before taking any of these products while taking Lamictal.
Does Lamictal interact with food?
There are currently no reports of Lamictal or Lamictal XR interacting with food. There aren’t any recommended foods to avoid when taking Lamictal (lamotrigine).
If you have questions about eating certain foods during your treatment with Lamictal, talk with your doctor.
Does Lamictal interact with vaccines?
There are currently no reports of Lamictal or Lamictal XR interacting with vaccines. If you have questions about getting certain vaccines during your Lamictal treatment, talk with your doctor.
Does Lamictal interact with lab tests?
Lamictal may interact with a urine drug test that screens for phencyclidine (PCP). Specifically, Lamictal may cause a false-positive result for PCP.
With a false-positive result, a test shows a positive result for a substance that is not present. If you’re taking Lamictal, the urine drug test may show a positive result for PCP even though Lamictal does not contain PCP.
If you’re taking a urine drug test for PCP, be sure the person giving the test knows you’re taking Lamictal. They’ll likely give you a different type of drug test that is not affected by Lamictal.
If you have questions about having certain lab tests during your Lamictal treatment, talk with the healthcare professional ordering the test.
Does Lamictal interact with cannabis or CBD?Cannabis (commonly called marijuana) and cannabis products, such as cannabidiol (CBD), have been specifically reported to interact with Lamictal. Cannabis products could increase your risk of side effects from Lamictal.
Before you start treatment with Lamictal, tell your doctor and pharmacist if you use cannabis. By sharing this information with them, you may help prevent possible interactions.
Note: Cannabis is illegal at a federal level but is legal in many states to varying degrees.
Certain medical conditions or other health factors may raise the risk of interactions with Lamictal. Before taking Lamictal, talk with your doctor about your health history. They’ll determine whether Lamictal is right for you.
Health conditions or other factors that might interact with Lamictal include:
Heart problems. Lamictal may cause certain heart problems. This can worsen any heart problem you already have.
Before taking Lamictal, tell your doctor if you have a heart condition. Examples include an irregular heart rhythm or heart failure. They can tell you whether Lamictal is a safe treatment option.
Liver or kidney problems. If you have a liver or kidney problem, talk with your doctor before starting Lamictal treatment. Examples of these problems include liver failure and kidney failure.
If you have a liver or kidney condition, your body may not break down Lamictal properly. This can lead to high levels of the drug in your system, which raises your risk of side effects. Your doctor may give you a lower dosage of Lamictal to reduce this risk. (To learn more about Lamictal’s dosage, see this article.)
Pregnancy. It’s not known whether Lamictal is safe to take during pregnancy. If you’re pregnant or planning a pregnancy, talk with your doctor before taking Lamictal.
If you do take Lamictal while pregnant, consider enrolling in the drug’s pregnancy registry. This registry collects details about pregnancy issues reported with Lamictal. To learn more, call 888-233-2334 or talk with your doctor.
Breastfeeding. Lamictal may not be safe to take while breastfeeding. The drug passes into breast milk and may cause side effects in a child who is breastfed. If you’re breastfeeding or planning to breastfeed, talk with your doctor about your options.
Allergic reaction. If you’ve had an allergic reaction to Lamictal or any of its ingredients, your doctor will likely not prescribe Lamictal. This is because taking the drug could cause another allergic reaction. You can ask your doctor about other treatments that may be better choices for you.
Mood changes, including depression. In rare cases, taking Lamictal may lead to suicidal thoughts or behaviors. Your risk may be higher if you have a mood disorder, such as depression. Your doctor can determine whether Lamictal is right for you.
Help is out there
If you or someone you know is in crisis and considering suicide or self-harm, please seek support:
- Call or text the 988 Suicide and Crisis Lifeline at 988.
- Text HOME to the Crisis Text Line at 741741.
- Not in the United States? Find a helpline in your country with Befrienders Worldwide.
- Call 911 or your local emergency services number if you feel safe to do so.
If you’re calling on behalf of someone else, stay with them until help arrives. You may remove weapons or substances that can cause harm if you can do so safely.
If you are not in the same household, stay on the phone with them until help arrives.
Find answers to some frequently asked questions about Lamictal and possible interactions.
Does Lamictal (lamotrigine) have interactions with antibiotics?
Yes, Lamictal has an interaction with the antibiotic drug rifampin (Rifadin, Rimactane). But Lamictal isn’t known to interact with other antibiotics.
Antibiotics are used to treat bacterial infections. If you have a bacterial infection during Lamictal treatment, your doctor may prescribe an antibiotic with Lamictal.
To learn more about Lamictal and rifampin, see the “Drug interactions explained” section above. If you have other questions about taking Lamictal and antibiotics together, talk with your doctor or pharmacist.
Are there any Lamictal (lamotrigine) interactions with antihistamines?
No. There aren’t any known interactions between Lamictal and antihistamines.
Antihistamines are used to ease symptoms of allergies and colds. Examples include:
- diphenhydramine (Benadryl, ZzzQuil, others)
- loratadine (Claritin)
- cetirizine (Zyrtec)
If you have allergy or cold symptoms during Lamictal treatment, your doctor can recommend an antihistamine to take with Lamictal.
If you have questions about taking Lamictal with antihistamines, talk with your doctor or pharmacist.
Taking certain steps can help you avoid interactions with Lamictal. Before starting treatment, talk with your doctor and pharmacist. Things to discuss with them include:
- Whether you drink alcohol or use cannabis.
- Other medications you take, as well as any vitamins, supplements, and herbs. Your doctor or pharmacist can help you fill out a
medication list . - What to do if you start taking a new drug during your Lamictal treatment.
It’s also important to understand Lamictal’s
If you have trouble reading or understanding this information, your doctor or pharmacist can help.
Taking Lamictal exactly as prescribed can also help prevent interactions.
If you still have questions about Lamictal and its possible interactions, talk with your doctor.
Questions you may want to ask your doctor include:
- Should I tell you if I start or stop another medication during my Lamictal treatment?
- Do other drugs that could treat my condition have similar interactions?
- Can I still take Lamictal even if it interacts with a health condition I have?
To learn more about Lamictal, see these articles:
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Disclaimer: Healthline 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.