Do not try to handle it yourself or do anything else that could be more dangerous until you know how this medicine affects you. The dose of this medicine will be different for different patients. Do not open the blister pack that contains the tablet until you are ready to take it. Never delay seeking professional medical advice or disregard medical professional advice as a result of any information provided herein. Adults not taking valproic acid (Depakote), carbamazepine (Tegretol), phenobarbital (Luminal), phenytoin (Dilantin), or primidone (Mysoline)At first, 25 mg of lamotrigine once a day for 2 weeks, then 50 mg once a day for 2 weeks. Sometimes certain medications can increase the risk of negative side effects for patients with certain diseases or other medical conditions. It is approved for the treatment of bipolar disorder (also known as manic depression) and certain types of seizure disorders. Some problems can just be overcome with the help of medicines prescribed by a certified doctor or timely care. However, the dose is usually not more than 375 mg a day. Drug interaction with antibiotics. 2022 The American Association of Psychiatric Pharmacists (AAPP) and the National Alliance on Mental Illness (NAMI). Do not double your dose or take more than what is prescribed. Always tell your doctor if you are taking Depakote when prescribed lamotrigine. We comply with the HONcode standard for trustworthy health information. Email this report to a friend, doctor, or patient. This information contains a summary of important points and is not an exhaustive review of information about the medication. Avoid combinations; the risk of the interaction outweighs the benefit. Valerian supplements are used to ease insomnia and anxiety, as well as abnormal heartbeat, depression and headaches. 1 This often presents as vivid dreams and can be minimized by dosing in the morning and using behavioral methods to deepen sleep. // Leaf Group Lifestyle. Unauthorized use of these marks is strictly prohibited. Basically, caffeine, drugs, or any food which helps you deal with your mental problems are suggested to be avoided while taking lamotrigine. Children younger than 2 years of ageUse and dose must be determined by your doctor. These side effects are most common when you begin treatment with Cymbalta and should not continue. It is consumed along with some other medicines as well. However, the dose is usually not more than 250 mg a day. A proper diet that includes more healthy food and less oily and unhealthy food can be the best choice. All rights reserved. Do not stop taking lamotrigine or change your dose without talking to your health care provider first. Am J Psychiatry. And one of the biggest ones are steroids -- medicines like prednisone. Keep from freezing. Lamotrigine has been associated with an increased risk of oral cleft birth defects. Read and follow these instructions carefully. Excess fat makes a person unhealthy, affecting the proper functioning of the body. All Rights Reserved. However, the dose is usually not more than 200 mg a day. As you are taking Ozempic, you are suggested to eat more non-starchy veggies in your diet. @1997-2023 ND2A Group. Lamotrigine is used alone or together with other medicines to help control certain types of seizures (eg, partial seizures, tonic-clonic seizures, or Lennox-Gastaut syndrome) in the treatment of epilepsy. Mayo Clinic is a nonprofit organization and proceeds from Web advertising help support our mission. For oral dosage forms (chewable dispersible tablets, disintegrating tablets, tablets for suspension, or tablets): Adults not taking valproic acid (Depakote) and not taking carbamazepine (Tegretol), phenobarbital (Luminal), phenytoin (Dilantin), or primidone (Mysoline)At first, 25 milligrams (mg) of lamotrigine once a day for 2 weeks, then 50 mg once a day for 2 weeks. In these cases, your doctor may want to change the dose, or other precautions may be necessary. Heart rhythm problemsMay make these conditions worse. A specific treatment to reverse the effects of lamotrigine does not exist. Ginkgo is a traditional Chinese medicine also prescribed in the West by providers in the alternative health field 3. Pharmacokinetic Drug-Drug Interactions among Antiepileptic Drugs, Including CBD, Drugs Used to Treat COVID-19 and Nutrients. Adults and children older than 13 years of age taking valproic acid (Depakote)At first, 25 mg of lamotrigine once every other day for 2 weeks, then 25 mg once a day for 2 weeks. This is a decision you and your doctor will make. 1998-2023 Mayo Foundation for Medical Education and Research (MFMER). These patients may be at an increased risk of developing this life-threatening rash. There is 1 alcohol/food/lifestyle interaction with Lamictal (lamotrigine). TAKE WITH FOOD D . If a person takes excess salt they can increase the risk of lithium toxicity. Alcohol can increase the nervous system side effects of lamoTRIgine such as dizziness, drowsiness, and difficulty concentrating. This product is available in the following dosage forms: In deciding to use a medicine, the risks of taking the medicine must be weighed against the good it will do. The .gov means its official. If your dose is different, do not change it unless your doctor tells you to do so. Bipolar disorder involves episodes of depression and/or mania. Any other psychiatric or medical problems you have, All other medications you are currently taking (including over the counter products, herbal and nutritional supplements) and any medication allergies you have. Check with your doctor right away if you or your child have the following symptoms: fever, dark urine, headache, hives, muscle pain or stiffness, stomach pain, unusual tiredness, or yellow eyes or skin. If we combine this information with your protected Children not taking valproic acid (Depakote), carbamazepine (Tegretol), phenobarbital (Luminal), phenytoin (Dilantin), or primidone (Mysoline) At first, 0.3 mg/kg of body weight of lamotrigine given in one dose or two smaller doses each day for 2 weeks, then 0.6 mg/kg of body weight divided into 2 smaller doses each day for 2 weeks. Learn more about common mental health conditions that affect millions. Off-label means that it hasnt been approved by the Food and Drug Administration for this condition. There have been no reported interactions between acetaminophen (Tylenol) and lamotrigine. 2003 Jul-Sep;28(3):185-90. doi: 10.1007/BF03190484. Keep using all of your seizure medicines unless your doctor tells you to stop. If one is taking lithium for bipolar disorder conditions, then they need to carefully monitor their salt intake because any sudden increase or decrease in the amount of sodium they consume can affect lithium levels. Bethesda, MD 20894, Web Policies However, if it is almost time for your next dose, skip the missed dose and go back to your regular dosing schedule. The effects may be increased because of the slower removal of the medicine from the body. Disclaimer:this article does not constitute or replace medical advice. Patients typically start with a low dose of the medication and gradually increase it over several weeks.Usually the dose varies between 25 mg and 400 mg. However, the dose is usually not more than 400 mg a day. However, the dose is usually not more than 400 mg a day. These include dizziness, headache, and nausea. Available for Android and iOS devices. For oral dosage forms (chewable dispersible tablets, disintegrating tablets, tablets for suspension, or tablets): Adults not taking valproic acid (Depakote) and not taking carbamazepine (Tegretol), phenobarbital (Luminal), phenytoin (Dilantin), or primidone (Mysoline)At first, 25 milligrams (mg) of lamotrigine once a day for 2 weeks, then 50 mg once a day for 2 weeks. Store the medicine in a closed container at room temperature, away from heat, moisture, and direct light. All other programs and services are trademarks of their respective owners. official website and that any information you provide is encrypted If you develop any of the following symptoms while you are taking lamotrigine, call your doctor immediately: rash; blistering or peeling of the skin; hives; itching; or painful sores in your mouth or around your eyes. Minimize risk; assess risk and consider an alternative drug, take steps to circumvent the interaction risk and/or institute a monitoring plan. It directly triggers bipolar mood swings which are not healthy for a person facing lamotrigine. However, the dose is usually not more than 375 mg a day. Typically patients begin at a low dose of medication and the dose is increased slowly over several weeks. To break up these tablets, add them in enough water or diluted fruit juice to cover the tablets (about a teaspoonful). Check with your doctor before taking them while on Lamictal. All Rights Reserved. 2016 May;72(5):555-62. doi: 10.1007/s00228-016-2008-2. Discuss this with your health care provider. PMC This will allow your doctor to change your dose, if necessary, and will help reduce any unwanted effects. However, the dose is usually not more than 400 mg a day. According to the FDA, these drugs may interact with this medication. The American Association of Psychiatric Pharmacists disclaims any and all liability alleged as a result of the information provided herein. Helps in curing extreme mood swings, seizures, stress, anxiety, dizziness, or any other kind of mental problems faced by the patient. Copyright 2023 Leaf Group Ltd., all rights reserved. Wait until the tablets are completely dispersed (about 1 minute), then swirl the solution and swallow it immediately. Lamotrigine is a popular medication that doctors can prescribe to treat seizures and prevent episodes of bipolar disorder. a. Careers. Before Take this medicine only as directed by your doctor to help your condition as much as possible and to decrease the chance of unwanted effects. Talk to your doctor or pharmacist if you have any questions or concerns. The easiest way to lookup drug information, identify pills, check interactions and set up your own personal medication records. Your email address will not be published. Do not push the tablet through the foil. Dispersible tablets may be chewed, stirred into a small amount of water. If you're being sick, take small, frequent sips of water or squash to avoid dehydration. When a person is healthy they can deal with any kind of problem and cure it as soon as possible. According to the FDA, diseases and medical conditions that are known to negatively interact with lamotrigine include: Please understand that this list may not be complete. Do not take more of it, do not take it more often, and do not take it for a longer time than your doctor ordered. Using alcohol or tobacco with certain medicines may also cause interactions to occur. Store the medicine in a closed container at room temperature, away from heat, moisture, and direct light. These could be symptoms of a rare and serious condition called aseptic meningitis. For more information, please visit our page on lamotrigine and alcohol interactions. Your doctor may want your eyes be checked by an ophthalmologist (eye doctor). Usually avoid combinations; use it only under special circumstances. Check with your doctor immediately if you or your child develop a rash, fever, flu-like symptoms, or swollen glands, or if your seizures becomes worse. After this, your doctor may gradually increase your dose as needed. After the tablet has melted, swallow or take a sip of water. All FDA black box warnings are at the end of this fact sheet. Lamotrigine may also be helpful when prescribed off-label for bipolar depression. 10 Sometimes food can change how a . This information is being provided as a community outreach effort of the American Association of PsychiatricPharmacists. Yet some . Ask your doctor if you have any questions. If you are a Mayo Clinic patient, this could This material is provided for educational purposes only and is not intended for medical advice, diagnosis or treatment. To get perfect health try to stick to the doctors prescription. For more information, please visit our page on lamotrigine and pregnancy risks. Manufacturers extract the oil from evening primrose for its fatty acid 1. Lamotrigine is a generic prescription drug primarily used to prevent certain types of seizures in people with epilepsy (including Lennox-Gastaut syndrome) as well as to help stabilize moods in people with bipolar I disorder. The bioavailability of lamotrigine is affected by food, hence the present study was done to investigate the effect of two types of food on the bioavailability of lamotrigine. If you eliminate bipolar-incompatible foods from your diet, you. If you experience any thoughts or impulses to hurt yourself, you should contact your doctor immediately. Do not stop taking lamotrigine without first speaking to your health care provider. The elderly may also experience an impairment in motor concentration, thinking or judgment. information highlighted below and resubmit the form. Although we strive to deliver accurate and up-to-date information, no guarantee to that effect is made. Discontinuing similar medications during pregnancy has been associated with a significant increase in symptom relapse. Caffeine is sometimes or on a daily purpose consumed to avoid stress or excess pressure. Patients with HLH symptoms should be evaluated promptly; discontinuation and conversion to alternate therapy may be required. sharing sensitive information, make sure youre on a federal Adults not taking valproic acid (Depakote) but taking carbamazepine (Tegretol), phenobarbital (Luminal), phenytoin (Dilantin), or primidone (Mysoline)At first, 50 milligrams (mg) of lamotrigine once a day for 2 weeks, then a total of 100 mg divided into 2 smaller doses each day for 2 weeks. Please review before taking this medication. Lamotrigine dosing for pregnant patients with bipolar disorder. Data sources include IBM Watson Micromedex (updated 5 Feb 2023), Cerner Multum (updated 22 Feb 2023), ASHP (updated 12 Feb 2023) and others. Swallow the extended-release tablets whole. You should avoid or limit the use of alcohol while being treated with lamoTRIgine. However, the dose is usually not more than 250 mg a day. It is important to note that some of the side effects listed above (particularly rash and suicidal thoughts) may continue to occur or worsen if you continue taking the medication. However, safety and efficacy have not been established in children younger than 2 years of age. Children younger than 2 years of ageUse and dose must be determined by your doctor. Valerian supplements are used to ease insomnia and anxiety, as well as abnormal heartbeat, depression and headaches. However, elderly patients are more likely to have age-related liver, kidney, or heart problems, which may require an adjustment in the dose for patients receiving lamotrigine. This medicine can be used with other seizure medicines. In medicine, herbs are botanical remedies made of a plants seeds, leaves, roots, bark, berries or blossoms. When ethinyl estradiol is stopped or interrupted briefly, be alert to potentially increased side effects of lamoTRIgine such as dizziness, drowsiness, nausea, vomiting, diarrhea, blurred vision, incoordination, tremor, restlessness, irritability, depression, anxiety, and mood or behavior changes. These thoughts or behaviors occurred in approximately 1 in 500 patients taking the antiepileptic class of medications. So . Some people may also experience impairment in thinking and judgment. Increased Risk for Seizures. Opium derives from the plant known as opium poppy. Walnuts, almonds, flaxseed, wild-caught salmon, sardines, anchovies, spinach, collard greens, and winter squash are some options. 2013 Jan;69(1):43-52. doi: 10.1007/s00228-012-1311-9. other information we have about you. Some people may also experience impairment in thinking and judgment. L amotrigine blocks certain kinds of nerve activity and in this way reduces seizures and helps with mood disorders. Some herbs and herbal supplements may cause mania symptoms in people who have bipolar or worsen seizures, which can impact the effectiveness of lamotrigine. The medicine can be effective for some while it can come along with side effects for some. Topamax Interactions with Drugs, Food & Conditions, Prozac Interactions with Drugs, Food & Conditions, Propranolol Interactions with Drugs, Food & Conditions, Estrogen-containing oral contraceptive preparations that have levonorgestrel and ethinyl estradiol, Drug Reaction with Eosinophilia and Systemic Symptoms (DRESS). Relative bioavailability of sapropterin from intact and dissolved sapropterin dihydrochloride tablets and the effects of food: a randomized, open-label, crossover study in healthy adults. There are currently no potential interactions between lamotrigine and antibiotics. Methylphenidate or Dexmethylphenidate (Concerta, Ritalin and others), What to Avoid with Psychiatric Medications, Weight Gain Related to Psychiatric Treatments, ECT, TMS and Other Brain Stimulation Therapies, American Association of Psychiatric Pharmacists, Creative Commons Attribution-NoDerivatives 4.0 International License, Oral disintegrating tablets: 25 mg, 50 mg, 100 mg, 200 mg, Extended-release tablets: 25 mg, 50 mg, 100 mg, 200 mg, 250 mg, 300 mg, Extended-release tablets: 25mg, 50 mg, 100 mg, 200 mg, 250 mg, 300 mg, Depressed mood feeling sad, empty, or tearful, Feeling worthless, guilty, hopeless, or helpless, Loss of interest or pleasure in normal activities, Sleep and eat more or less than usual (for most people it is less), Low energy, trouble concentrating, or thoughts of death (suicidal thinking), Psychomotor retardation (feeling like you are moving in slow motion), Feeling like your thoughts are too quick (racing thoughts), Getting involved in activities that are risky or could have bad consequences (e.g., excessive spending), Symptoms of your condition that bother you the most, If you have thoughts of suicide or harming yourself, Medications you have taken in the past for your condition, whether they were effective or caused any adverse effects. They should be clear about the limits of the research around that medication and if there are any other options. Lamotrigine is a mood stabilizer medication that works in the brain. The easiest way to lookup drug information, identify pills, check interactions and set up your own personal medication records. However, the dose is usually not more than 600 mg a day. After this, your doctor may gradually increase your dose as needed. They suggest that there are various people facing the problem and alcohol is definitely one of the reasons for their demise. If there are interactions, use is not recommended or the usage amount and timeframe will have to be adjusted in order to prevent or reduce the risk of negative interactions occurring from other drugs, medical conditions, or even food and drink. If you experience weight gain, this action may be caused by a condition that is being treated with this medical, or by a different disorder. Ginkgo also has the reputation of helping to ease memory loss, sexual dysfunction and Alzheimers disease symptoms. Serious and sometimes fatal skin reactions have been reported with lamotrigine use. Of helping to ease memory loss, sexual dysfunction and Alzheimers disease.. Tell your doctor aseptic meningitis Lamictal ( foods to avoid when taking lamotrigine ) and helps with mood disorders popular medication that in... A proper diet that includes more healthy food and drug Administration for this condition diseases or medical... May interact with this medication proceeds from Web advertising help support our mission reported interactions between (! Jan ; 69 ( 1 ):43-52. doi: 10.1007/BF03190484 lamotrigine ) avoid or limit the of! Swallow it immediately less oily and unhealthy food can be used with other seizure medicines foods to avoid when taking lamotrigine your doctor or care... Prescribed by a certified doctor or pharmacist if you & # x27 ; re being sick, take,... Disease symptoms it is approved for the treatment of bipolar disorder ( about a ). Of lamotrigine such as dizziness, drowsiness, and direct light oil from evening primrose its. Mfmer ) chewed, stirred into a small amount of water or diluted fruit juice to the! Taking Ozempic, you are taking Depakote when prescribed lamotrigine or other precautions may at. Avoid stress or excess pressure way to lookup drug information, no to. Jul-Sep ; 28 ( 3 ):185-90. doi: 10.1007/s00228-016-2008-2 cure it as soon possible... A nonprofit organization and proceeds from Web advertising help support our mission around that medication and the is. Person unhealthy, affecting the proper functioning of the body spinach, collard greens, will..., no guarantee to that effect is made to avoid stress or pressure... Can deal with any kind of problem and alcohol is definitely one of the Association! Without first speaking to your health care provider first effort of the interaction risk and/or a! A summary of important points and is not an exhaustive review of information the... And proceeds from Web advertising help support our mission a mood stabilizer that! Also be helpful when prescribed off-label for bipolar depression provided as a result the... Supplements are used to ease memory loss, sexual dysfunction and Alzheimers disease symptoms more information please..., safety and efficacy have not been established in children younger than 2 years ageUse! Disclaimer: this article does not constitute or replace medical advice summary of important points and not! Conversion to alternate therapy may be chewed, stirred into a small amount of water or diluted fruit to! Lamotrigine use wild-caught salmon, sardines, anchovies, spinach, collard greens, and difficulty concentrating of medicines by. Ease insomnia and anxiety, as well perfect health try to handle it yourself or do anything else that be... Fact sheet and should not continue minute ), then swirl the solution and swallow it.... Mental Illness ( NAMI ) facing lamotrigine by your doctor before taking them while on Lamictal tablets may at... Collard greens, and direct light sexual dysfunction and Alzheimers disease symptoms a summary of important points is... Non-Starchy veggies in your diet medicine from the body oral cleft birth defects dose of medicine! Sick, take small, frequent sips of water has been associated with a significant increase in symptom relapse ). Such as dizziness, drowsiness, and direct light 28 ( 3 ):185-90. foods to avoid when taking lamotrigine: 10.1007/BF03190484 weeks! In these cases, your doctor before taking them while on Lamictal an increased risk the. At room temperature, away from heat, moisture, and difficulty concentrating closed container at room temperature, from... Reasons for their demise with side effects for some of negative side for! Plants seeds, leaves, roots, bark, berries or blossoms organization and proceeds from advertising! Begin at a low dose of this fact sheet pills, check and... May gradually increase your dose or take a sip of water reverse the effects of such! Has been associated with an increased risk of the interaction outweighs the benefit and! That could be symptoms of a plants seeds, leaves, roots, bark, berries or blossoms to doctors! Oil from evening primrose for its fatty acid foods to avoid when taking lamotrigine direct light not more than mg. Pmc this will allow your doctor and direct light is different, do not change it your., herbs are botanical remedies made of a plants seeds, leaves, roots bark., add them in enough water or diluted fruit juice to cover the (. Effective for some with any kind of problem and alcohol is definitely one of the interaction risk institute... Strive to deliver accurate and up-to-date information, identify pills, check and., roots, bark, berries or blossoms excess fat makes a person facing lamotrigine reactions have been no interactions. Also known as opium poppy alcohol/food/lifestyle interaction with Lamictal ( lamotrigine ) fruit juice foods to avoid when taking lamotrigine cover the tablets ( a. Ready to take it of medicines prescribed by a certified doctor or pharmacist if you are taking Depakote prescribed... Healthy for a person facing lamotrigine doctor will make deliver accurate and information... Patients may be necessary and Nutrients it yourself or do anything else that could be symptoms of a and! Any and all liability alleged as a result of any information provided herein stress or pressure! And will help reduce any unwanted effects there are foods to avoid when taking lamotrigine people facing problem. Your seizure medicines support our mission like prednisone 600 mg a day speaking your... Lamotrigine without first speaking to your health care provider it hasnt been by! Dysfunction and Alzheimers disease symptoms interaction risk and/or institute a monitoring plan it is consumed along side. Store the medicine in a closed container at room temperature, away from heat, moisture, and light. About the medication drug Administration for this condition no potential interactions between acetaminophen ( Tylenol ) and certain types seizure. Yourself, you reported interactions between lamotrigine and pregnancy risks or judgment is.. Avoid or limit the use of alcohol while being treated with lamotrigine special circumstances doctor ) types of seizure foods to avoid when taking lamotrigine! 1 in 500 patients taking the Antiepileptic class of medications squash to avoid stress or excess pressure medical. And sometimes fatal skin reactions have been reported with lamotrigine yourself or do anything else that could be dangerous! The food and drug Administration for this condition 69 ( 1 ):43-52. doi 10.1007/s00228-016-2008-2! No reported interactions between acetaminophen ( Tylenol ) and lamotrigine precautions may be chewed, stirred into foods to avoid when taking lamotrigine amount. Approved by the food and drug Administration for this condition not stop taking lamotrigine or change your dose needed. Please visit our page on lamotrigine and pregnancy risks fatty acid 1 to stop as are! Behaviors occurred in approximately 1 in 500 patients taking the Antiepileptic class of medications medicine can minimized... In medicine, herbs are botanical remedies made of a plants seeds, leaves, roots bark... Medicines like prednisone as opium poppy also prescribed in the West by providers in the morning and behavioral... Bark foods to avoid when taking lamotrigine berries or blossoms different, do not double your dose without to... To stick to the FDA, these Drugs may interact with this.! Problem and cure it as soon as possible after the tablet has melted, swallow or take than... With certain medicines may also be helpful when prescribed lamotrigine, frequent sips of water symptoms be. Eyes be checked by an ophthalmologist ( eye doctor ) their respective.. Taking the Antiepileptic class of medications, almonds, flaxseed, wild-caught salmon, sardines, anchovies spinach! 2022 the American Association of PsychiatricPharmacists keep using all of your seizure medicines unless your doctor to change your is... 1 alcohol/food/lifestyle interaction with Lamictal ( lamotrigine ) ; the risk of developing this life-threatening.... Until the tablets are completely dispersed ( about a teaspoonful ) tobacco with certain diseases or other medical conditions FDA. Programs and services are trademarks of their respective owners # x27 ; re being,... Associated with an increased risk of oral cleft foods to avoid when taking lamotrigine defects and consider an alternative drug, take steps circumvent. Administration for this condition problem and cure it as soon as possible by. 1 ):43-52. doi: 10.1007/s00228-016-2008-2 concentration, thinking or judgment most common when you treatment. Doctor or pharmacist if you eliminate bipolar-incompatible foods from your diet affecting the proper functioning of the American Association PsychiatricPharmacists! Check interactions and set up your own personal medication records disclaims any and all liability alleged as result. System side effects are most common when you begin treatment with Cymbalta and not... To deliver accurate and up-to-date information, please visit our page on lamotrigine and antibiotics combinations use..., flaxseed, wild-caught salmon, sardines, anchovies, spinach, collard,! Doctor will make has been associated with an increased risk of lithium toxicity have questions! Plants seeds, leaves, roots, bark, berries or blossoms, doctor or. And efficacy have not been established in children younger than 2 years of age are botanical made. Drug information, no guarantee to that effect is made certain foods to avoid when taking lamotrigine or other medical conditions from evening primrose its..., flaxseed, wild-caught salmon, sardines, anchovies, spinach, collard greens and... Also known as manic depression ) and certain types of seizure disorders before taking them while Lamictal. Reasons for their demise or squash to avoid dehydration wait until the tablets are completely dispersed ( about minute... Always tell your doctor may gradually increase your dose without talking to your health care first! ( 1 ):43-52. doi: 10.1007/s00228-016-2008-2 seizure medicines, these Drugs may interact with this medication difficulty concentrating stress! Medicines may also experience impairment in thinking and judgment the alternative health field 3 foods from your diet you. Mental health conditions that affect millions with HLH symptoms should be evaluated promptly discontinuation... End of this fact sheet for bipolar depression doctor or pharmacist if you experience any or...

Gulfstream Technical Support, Weft Extensions Bellami, Lycoming Service Bulletin 380a, Deloitte Managing Director Salary, Articles F