Lamotrigine is used alone or with other medications to prevent and control seizures. It may also be used to help prevent the extreme mood swings of bipolar disorder in adults. Lamotrigine is known as an anticonvulsant or antiepileptic drug. It is thought to work by restoring the balance of certain natural substances in the brain. This drug is not approved for use in children younger than 2 years due to an increased risk of side effects (such as infections).
Read the Medication Guide and, if available, the Patient Information Leaflet provided by your pharmacist before you start taking lamotrigine and each time you get a refill. If you have any questions, ask your doctor or pharmacist. Take this medication by mouth with or without food as directed by your doctor. Swallow the tablets whole since chewing them may leave a bitter taste. Dosage is based on your medical condition, response to treatment, and use of certain interacting drugs. (See also Drug Interactions section.) For children, the dosage is also based on weight. It is very important to follow your doctor's dosing instructions exactly. The dose must be increased slowly. It may take several weeks or months to reach the best dose for you and to get the full benefit from this medication. Take this medication regularly in order to get the most benefit from it. To help you remember, take it at the same time(s) each day. Do not stop taking this medication without consulting your doctor. Some conditions may become worse when the drug is suddenly stopped. Your dose may need to be gradually decreased. Also, if you have stopped taking this medication, do not restart lamotrigine without consulting your doctor. Tell your doctor if your condition does not improve or if it worsens.
See also Warning section. Dizziness, drowsiness, headache, vomiting, or upset stomach may occur. If any of these effects persist or worsen, tell your doctor or pharmacist promptly. Remember that your doctor has prescribed this medication because he or she has judged that the benefit to you is greater than the risk of side effects. Many people using this medication do not have serious side effects. A small number of people who take anticonvulsants for any condition (such as seizures, bipolar disorder, pain) may experience depression, suicidal thoughts/attempts, or other mental/mood problems. Tell your doctor right away if you or your family/caregiver notice any unusual/sudden changes in your mood, thoughts, or behavior including signs of depression, suicidal thoughts/attempts, thoughts about harming yourself. Get medical help right away if any of these rare but serious side effects occur: fainting, fast/irregular/pounding heartbeat, easy or unusual bruising/bleeding, stiff neck, vision problems, loss of coordination, muscle pain/tenderness/weakness, signs of kidney problems (such as change in the amount of urine). This is not a complete list of possible side effects. If you notice other effects not listed above, contact your doctor or pharmacist. In the US - Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088 or at www.fda.gov/medwatch. In Canada - Call your doctor for medical advice about side effects. You may report side effects to Health Canada at 1-866-234-2345.
Store at room temperature away from light and moisture. Do not store in the bathroom. Keep all medications away from children and pets. Do not flush medications down the toilet or pour them into a drain unless instructed to do so. Properly discard this product when it is expired or no longer needed. Consult your pharmacist or local waste disposal company.
Drug interactions may change how your medications work or increase your risk for serious side effects. This document does not contain all possible drug interactions. Keep a list of all the products you use (including prescription/nonprescription drugs and herbal products) and share it with your doctor and pharmacist. Do not start, stop, or change the dosage of any medicines without your doctor's approval. Some products that may interact with this drug include: dofetilide, orlistat. Other medications can affect the removal of lamotrigine from your body, which may affect how lamotrigine works. Examples include hormonal birth control (such as pills, patches), estrogens, other medications to treat seizures (such as phenobarbital, phenytoin, primidone, valproic acid), certain HIV protease inhibitors (such as lopinavir/ritonavir, atazanavir/ritonavir), and rifampin, among others. Your doctor may need to adjust your dose of lamotrigine if you are on these medications. This medication may decrease the effectiveness of hormonal birth control products (such as pills, patch, ring). This effect can result in pregnancy. Ask your doctor or pharmacist for details. Discuss whether you should use additional reliable birth control methods while using this medication. Also tell your doctor if you have any new spotting or breakthrough bleeding, because these may be signs that your birth control is not working well. Tell your doctor or pharmacist if you are taking other products that cause drowsiness including alcohol, marijuana (cannabis), antihistamines (such as cetirizine, diphenhydramine), drugs for sleep or anxiety (such as alprazolam, diazepam, zolpidem), muscle relaxants, and narcotic pain relievers (such as codeine). Check the labels on all your medicines (such as allergy or cough-and-cold products) because they may contain ingredients that cause drowsiness. Ask your pharmacist about using those products safely. This medication may interfere with certain laboratory tests (including urine drug screening tests), possibly causing false test results. Make sure laboratory personnel and all your doctors know you use this drug.
If someone has overdosed and has serious symptoms such as passing out or trouble breathing, call 911. Otherwise, call a poison control center right away. US residents can call their local poison control center at 1-800-222-1222. Canada residents can call a provincial poison control center. Symptoms of overdose may include: severe drowsiness, unusual eye movements, loss of consciousness.