Mefloquine may cause serious side effects that include nervous system changes. Tell your doctor if you have or have ever had seizures. Your doctor may tell you not to take mefloquine. If you notice any of the following symptoms while taking this medication, call your doctor immediately: dizziness, a feeling that you or things around you are moving or spinning, ringing in the ears, and loss of balance. These symptoms may occur at any time while you are taking mefloquine and can last for months to years after the medication is stopped or can be permanent.
Mefloquine may cause serious mental health problems. Tell your doctor if you have or have ever had depression, anxiety, psychosis (difficulty thinking clearly, understanding reality, and communicating and behaving appropriately), schizophrenia (an illness that causes disturbed or unusual thinking, loss of interest in life, and strong or inappropriate emotions) or other mental health disorders. Also tell your doctor immediately if you develop the following symptoms while taking this medication: anxiety, feelings of mistrust towards others, hallucinations (seeing things or hearing voices that do not exist), depression, thoughts of suicide or harming yourself, restlessness, confusion, difficulty falling asleep or staying asleep, or unusual behavior. These symptoms may occur at any time while you are taking mefloquine and can last for months to years after the medication is stopped.
These symptoms of nervous system changes or mental health problems may be more difficult to note in young children. Watch your child carefully and contact their doctor right away if you find any changes in behavior or health.
Keep all appointments with your doctor, eye doctor, and the laboratory. Your doctor may order certain lab tests and periodic eye examinations to check your body's response to mefloquine.
Your doctor or pharmacist will give you the manufacturer's patient information sheet (Medication Guide) when you begin treatment with mefloquine and each time you refill your prescription. Read the information carefully and ask your doctor or pharmacist if you have any questions. You can also visit the Food and Drug Administration (FDA) website ( Web Site) or the manufacturer's website to obtain the Medication Guide.
Talk to your doctor about the risks of taking mefloquine.
Mefloquine is used to treat malaria (a serious infection that is spread by mosquitoes in certain parts of the world and can cause death) and to prevent malaria in travelers who visit areas where malaria is common. Mefloquine is in a class of medications called antimalarials. It works by killing the organisms that cause malaria.
Mefloquine comes as a tablet to take by mouth. Always take mefloquine with food (preferably your main meal) and at least 8 ounces (240 milliliters) of water. If you are taking mefloquine to prevent malaria, you will probably take it once a week (on the same day each week). You will begin treatment 1 to 3 weeks before you travel to an area where malaria is common and should continue treatment for 4 weeks after you return from the area. If you are taking mefloquine to treat malaria, your doctor will tell you exactly how often you should take it. Children may take smaller but more frequent doses of mefloquine. Follow the directions on your prescription label carefully, and ask your doctor or pharmacist to explain any part you do not understand. Take mefloquine exactly as directed. Do not take more or less of it or take it more often than prescribed by your doctor.
The tablets may be swallowed whole or crushed and mixed with water, milk, or other beverage.
If you are taking mefloquine to treat malaria, you may vomit soon after you take the medication. If you vomit less than 30 minutes after you take mefloquine, you should take another full dose of mefloquine. If you vomit 30 to 60 minutes after you take mefloquine, you should take another half dose of mefloquine. If you vomit again after taking the extra dose, call your doctor.
This medication may be prescribed for other uses; ask your doctor or pharmacist for more information.
Before taking mefloquine,
- tell your doctor and pharmacist if you are allergic to mefloquine, quinidine (Quinadex), quinine (Qualaquin), any other medications, or any of the ingredients in mefloquine tablets.
- tell your doctor and pharmacist what prescription and nonprescription medications, vitamins, nutritional supplements, and herbal products you are taking. Be sure to mention any of the following: anticoagulants ('blood thinners'); antidepressants such as amitriptyline (Elavil), amoxapine (Asendin), clomipramine (Anafranil), desipramine (Norpramin), doxepin (Adapin, Sinequan), imipramine (Tofranil), nortriptyline (Aventyl, Pamelor), protriptyline (Vivactil), and trimipramine (Surmontil); antihistamines; calcium channel blockers such as amlodipine (Norvasc), diltiazem (Cardizem, Dilacor, Tiazac), felodipine (Plendil), isradipine (DynaCirc), nicardipine (Cardene), nifedipine (Adalat, Procardia), nimodipine (Nimotop), nisoldipine (Sular), and verapamil (Calan, Isoptin, Verelan); beta blockers such as atenolol (Tenormin), labetalol (Normodyne), metoprolol (Lopressor, Toprol XL), nadolol (Corgard), and propranolol (Inderal); chloroquine (Aralen); medication for diabetes, mental illness, seizures and upset stomach; medications for seizures such as carbamazepine (Tegretol), phenobarbital (Luminal), phenytoin (Dilantin), or valproic acid (Depakene); and rifampin (Rifadin, Rimactane, in Rifamate, in Rifater). Also tell your doctor or pharmacist if you are taking the following medications or have stopped taking them within the past 15 weeks: halofantrine (Halfan; no longer available in the United States) or ketoconazole (Nizoral). Your doctor may need to change the doses of your medications or monitor you carefully for side effects.
- tell your doctor if you have or have ever had any of the conditions mentioned in the IMPORTANT WARNING section or any of the following: a prolonged QT interval (a rare heart problem that may cause irregular heartbeat, fainting, or sudden death), anemia (a lower than normal number of red blood cells), or eye, liver or heart disease.
- tell your doctor if you are pregnant or plan to become pregnant, or are breast-feeding. You should use birth control while you are taking mefloquine and for 3 months after you stop taking it. If you become pregnant while taking mefloquine, call your doctor.
- you should know that mefloquine may make you drowsy and dizzy. These symptoms may continue for a while after you stop taking mefloquine. Do not drive a car or operate machinery until you know how this medication affects you.
- you should know that mefloquine decreases your risk of becoming infected with malaria but does not guarantee that you will not become infected. You still need to protect yourself from mosquito bites by wearing long sleeves and long pants and using mosquito repellant and a bed net while you are in an area where malaria is common.
- you should know that the first symptoms of malaria are fever, chills, muscle pain, and headaches. If you are taking mefloquine to prevent malaria, call your doctor immediately if you develop any of these symptoms. Be sure to tell your doctor that you may have been exposed to malaria.
- you should plan what to do in case you experience serious side effects from mefloquine and have to stop taking the medication, especially if you are not near a doctor or pharmacy. You will have to get another medication to protect you from malaria. If no other medication is available, you will have to leave the area where malaria is common, and then get another medication to protect you from malaria.
- if you are taking mefloquine to treat malaria, your symptoms should improve within 48 to 72 hours after you finish your treatment. Call your doctor if your symptoms do not improve after this time.
- do not have any vaccinations (shots) without talking to your doctor. Your doctor may want you to finish all of your vaccinations 3 days before you start taking mefloquine.
Unless your doctor tells you otherwise, continue your normal diet.
Take the missed dose as soon as you remember it. However, if it is almost time for the next dose, skip the missed dose and continue your regular dosing schedule. Do not take a double dose to make up for a missed one.
Mefloquine may cause side effects. Tell your doctor if any of these symptoms are severe or do not go away:
- pain on the right side of your stomach
- loss of appetite
- muscle pain
- increased sweating
Some side effects can be serious. The following symptoms are uncommon, but if you experience any of the following symptoms or those listed in the IMPORTANT WARNING or SPECIAL PRECAUTIONS section, call your doctor immediately:
- tingling in your fingers or toes
- difficulty walking
- light-colored bowel movements
- dark colored urine
- yellowing of your skin or the white of your eyes
- shaking of arms or legs that you cannot control
- changes in vision
- muscle weakness
- shortness of breath
- chest pain
- panic attack
Mefloquine may cause other side effects. You may continue to experience side effects for some time after you take your last dose. Call your doctor if you have any unusual problems while taking this medication.
If you experience a serious side effect, you or your doctor may send a report to the Food and Drug Administration's (FDA) MedWatch Adverse Event Reporting program online [at Web Site] or by phone [1-800-332-1088].
Keep this medication in the container it came in, tightly closed, and out of reach of children. Store it at room temperature and away from excess heat and moisture (not in the bathroom). Throw away any medication that is outdated or no longer needed. Talk to your pharmacist about the proper disposal of your medication.
In case of overdose, call your local poison control center at 1-800-222-1222. If the victim has collapsed or is not breathing, call local emergency services at 911.
Symptoms of overdose may include the following:
- pain on the right side of your stomach
- loss of balance
- difficulty falling or staying asleep
- unusual dreams
- tingling in your fingers or toes
- difficulty walking
- changes in mental health
Do not let anyone else take your medication. Ask your pharmacist any questions you have about refilling your prescription.
It is important for you to keep a written list of all of the prescription and nonprescription (over-the-counter) medicines you are taking, as well as any products such as vitamins, minerals, or other dietary supplements. You should bring this list with you each time you visit a doctor or if you are admitted to a hospital. It is also important information to carry with you in case of emergencies.
¶This branded product is no longer on the market. Generic alternatives may be available.
AHFS® Consumer Medication Information. © Copyright, The American Society of Health-System Pharmacists, Inc., 7272 Wisconsin Avenue, Bethesda, Maryland. All Rights Reserved. Duplication for commercial use must be authorized by ASHP.
Selected Revisions: October 15, 2013.