Mefloquine (patient information)

Why this medication is prescribed

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.

How this medication should be used

Mefloquine comes as a tablet to take by mouth. 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 1-3 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. Always take mefloquine with food (preferably your main meal) and at least 8 ounces of water. 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 a liquid such as water, milk, or sugar water.

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 30-60 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.

Other uses for this medicine

This medication may be prescribed for other uses; ask your doctor or pharmacist for more information.

Special precautions

Before taking mefloquine:

• tell your doctor and pharmacist if you are allergic to mefloquine, chloroquine (Aralen), hydroxychloroquine (Plaquenil), quinidine (Quinadex), quinine or any other medications.
• 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, others), 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); halofantrine (Halfan); hydroxychloroquine (Plaquenil); medication for diabetes, mental illness, seizures and upset stomach; medications for irregular heartbeat such as quinidine (Quinaglute, Quinidex); and quinine. 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 a mental illness such as depression, generalized anxiety disorder, psychosis (losing touch with reality), or schizophrenia (abnormal thoughts or feelings); seizures; or eye, liver or heart disease.
• tell your doctor if you are pregnant or plan to become pregnant. You should use birth control while you are visiting an area where malaria is common and 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 not breastfeed while taking mefloquine.
• 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 bednet 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 48-72 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.
• you should know that mefloquine may damage your liver or eyes if you take it for a long time. *Your doctor will tell you if you should have your eyes and liver checked while taking mefloquine.

Special dietary instructions

Unless your doctor tells you otherwise, continue your normal diet.

What to do if you forget a dose

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.

Side effects

Minor side effects

Mefloquine may cause side effects. Tell your doctor if any of these symptoms are severe or do not go away:

• upset stomach
• vomiting
• diarrhea
• stomach pain
• loss of appetite
• muscle pain
• dizziness
• loss of balance
• ringing in ears
• headache
• sleepiness
• difficulty falling or staying asleep
• unusual dreams

Severe side effects

Some side effects can be serious. The following symptoms are uncommon, but if you experience any of them, call your doctor immediately:

• tingling in your fingers or toes
• difficulty walking
• seizures
• shaking of arms or legs that you cannot control
• nervousness or extreme worry
• depression
• changes in mood
• panic attack
• forgetfulness
• confusion
• hallucinations (seeing things or hearing voices that do not exist)
• violent behavior
• losing touch with reality
• feeling that others want to harm you
• thoughts of hurting or killing yourself
• rash

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 http://www.fda.gov/MedWatch/report.htm] or by phone [1-800-332-1088].

Storage conditions needed for this medication

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 emergency/overdose

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:

• upset stomach
• vomiting
• diarrhea
• stomach pain
• dizziness
• loss of balance
• headache
• sleepiness
• difficulty falling or staying asleep
• unusual dreams
• tingling in your fingers or toes
• difficulty walking
• seizures
• changes in mental health

Other information

Keep all appointments with your doctor and the laboratory. Your doctor may order certain lab tests and periodic eye examinations to check your body's response to mefloquine.

Do not let anyone else take your medication. Ask your pharmacist any questions you have about refilling your prescription.

Brand names

• Lariam®