Generic Name: Lariam Brand Name(s): Generics only. No brands available.


What is Lariam® (mefloquine HCL) used for?

Lariam® is an antimalarial agent. It is commonly used for treating or preventing malaria.

How should I take Lariam® (mefloquine HCL)?

Use Lariam® as directed by your doctor. Check the label on the medicine for exact dosing instructions.

Take Lariam® by mouth with a full glass of water right after you eat your main meal. Do not take it on an empty stomach.

If the tablets cannot be swallowed whole, they may be crushed and mixed with a small amount of water, milk, or other beverage. Be sure to drink all the liquid so that you receive the entire dose.

Weekly doses of Lariam® should be taken regularly, on the same day of each week, preferably after the main meal of the day.

Continue to use Lariam® for the full course of treatment. Do not miss any doses. Malaria can be life-threatening.

How do I store Lariam® (mefloquine HCL)?

Lariam® is best stored at room temperature away from direct light and moisture. To prevent drug damage, you should not store Lariam® in the bathroom or the freezer. There may be different brands of Lariam® that may have different storage needs. It is important to always check the product package for instructions on storage, or ask your pharmacist. For safety, you should keep all medicines away from children and pets.

You should not flush Lariam® down the toilet or pour them into a drain unless instructed to do so. It is important to properly discard this product when it is expired or no longer needed. Consult your pharmacist for more details about how to safely discard your product.

Precautions & warnings

What should I know before using Lariam® (mefloquine HCL)?

Tell your doctor if:

  • if you are pregnant, planning to become pregnant, or are breast-feeding
  • if you are taking any prescription or nonprescription medicine, herbal preparation, or dietary supplement
  • if you have allergies to medicines, foods, or other substances

Before using this drug, you may notice that:

  • Lariam® may cause drowsiness, dizziness, light-headedness, or a loss of balance. These effects may be worse if you take it with alcohol or certain medicines. Effects of Lariam® may continue for a period of time (e.g., several weeks) or may not go away, even after you stop taking it. Use Lariam® with caution. Do not drive or perform other possibly unsafe tasks until you know how you react to it.
  • Tell your doctor or dentist that you take Lariam® before you receive any medical or dental care, emergency care, or surgery.
  • Lariam® may decrease the effectiveness of live vaccines. Check with your doctor before you receive any vaccines while you are using Lariam®.
  • Women who may become pregnant should use effective birth control while taking Lariam® and for up to 3 months after stopping treatment. Check with your doctor if you have questions about using birth control.
  • Contact your doctor right away if you experience mental or mood changes (e.g., anxiety, depression, restlessness, confusion, hallucinations, paranoia). You may need to stop taking Lariam® and start a different malaria medicine.
  • If you have to stop taking Lariam® for any reason and you do not have access to a doctor or to another malaria medicine, leave the malaria area and contact a doctor as soon as possible. Leaving the area may not protect you from contracting malaria. You may still need to take another medicine to prevent the disease.
  • No medicine is completely effective against malaria. While you are in an area where malaria exists, use bed nets and insect repellents and wear protective clothing (long sleeves and long pants) to decrease your risk. In some situations, you may want to pre-wash your clothes with permethrin, a mosquito repellent that may be effective for weeks after use. Ask your doctor for other ways to protect yourself.
  • Contact your health care provider at once if you develop a fever or flu-like symptoms (e.g., chills, headache, muscle pains) after returning from an area where malaria exists.
  • If you are using Lariam® to treat malaria and your symptoms do not improve within 48 to 72 hours, contact your doctor right away.
  • If your doctor tells you to stop taking Lariam®, you will need to wait for at least 15 weeks before you start to take certain other medicines (e.g., halofantrine, ketoconazole). Ask your doctor when you should start to take any new medicines after you stop Lariam®.
  • Lab tests, including liver function, complete blood cell count, and eye exams, may be performed while you use Lariam®. These tests may be used to monitor your condition or check for side effects. Be sure to keep all doctor and lab appointments.
  • Use Lariam® with caution in the elderly; they may be more sensitive to its effects, especially heart problems.
  • Lariam® should not be used in children who are younger than 6 months old or who weigh less than 44 lbs (20 kg); safety and effectiveness in these children have not been confirmed.
  • Lariam® may cause vomiting, especially in children. Check with your doctor to see if you should take another dose if you vomit after taking Lariam®.
  • If you are taking Lariam® to prevent malaria, begin taking it 1 week before traveling. Continue to take it for 4 weeks after leaving the malaria area. If you cannot complete the treatment, contact your doctor.
  • If you are taking other medicines, ask your doctor if you should start taking Lariam® 2 to 3 weeks before traveling in order to make sure that the combination of medicines is well tolerated.

Is it safe during pregnancy or breastfeeding?


Do not become pregnant while you are taking Lariam®. If you think you may be pregnant, contact your doctor. You will need to discuss the benefits and risks of using Lariam® while you are pregnant.


Lariam® is found in breast milk. Do not breastfeed while taking Lariam®.

Side effects

What side effects can occur from Lariam® (mefloquine HCL)?

All medicines may cause side effects, but many people have no, or minor, side effects. Check with your doctor if any of these most common side effects persist or become bothersome:

  • Diarrhea
  • Dizziness
  • Drowsiness
  • Headache
  • Light-headedness
  • Loss of appetite
  • Muscle aches
  • Nausea
  • Stomach pain or upset
  • Strange dreams
  • Tiredness
  • Trouble sleeping
  • Vomiting

Seek medical attention right away if any of these severe side effects occur:

  • Rash
  • Hives
  • Itching
  • Difficulty breathing
  • Tightness in the chest
  • Swelling of the mouth, face, lips, or tongue
  • Bizarre behavior
  • Chest pain
  • Fainting
  • Fast, slow, or irregular heartbeat
  • Flu-like symptoms (e.g., chills, fever, headache, muscle pain)
  • Loss of balance or coordination
  • Memory problems
  • Mental or mood changes (e.g., anxiety, confusion, depression, hallucinations, mood changes, paranoia, restlessness)
  • Numbness or tingling of the hands or feet
  • Red, swollen, or blistered skin
  • Ringing in the ears
  • Seizures
  • Severe or persistent cough
  • Shortness of breath
  • Suicidal thoughts or attempts
  • Symptoms of liver problems (e.g., dark urine, pale stools, persistent stomach pain or loss of appetite, persistent tiredness, yellowing of the skin or eyes)
  • Tremor
  • Vision changes

Not everyone experiences these side effects. There may be some side effects not listed above. If you have any concerns about a side-effect, please consult your doctor or pharmacist.


What drugs may interact with Lariam® (mefloquine HCL)?

Lariam® may interact with other drugs that you are currently taking, which can change how your drug works or increase your risk for serious side effects. To avoid any potential drug interactions, you should keep a list of all the drugs you are using (including prescription drugs, nonprescription drugs, and herbal products) and share it with your doctor and pharmacist. For your safety, do not start, stop, or change the dosage of any drugs without your doctor’s approval.

Products may interact with this drug, including:

  • Antiarrhythmics (e.g., amiodarone, propafenone, quinidine)
  • Certain antihistamines (e.g., astemizole, terfenadine)
  • Beta-blockers (e.g., propranolol)
  • Calcium channel blockers (e.g., amlodipine, verapamil)
  • Chloroquine
  • Dofetilide
  • Halofantrine
  • Hydroxychloroquine
  • Ketoconazole
  • Paliperidone
  • Phenothiazines (e.g., thioridazine)
  • Quinine
  • Tricyclic antidepressants (e.g., amitriptyline)
  • Ziprasidone
  • Anticoagulants (e.g., warfarin)
  • Rifampin
  • Anticonvulsants (e.g., valproic acid, carbamazepine, phenobarbital, phenytoin)

Does food or alcohol interact with Lariam® (mefloquine HCL)?

Lariam® may interact with food or alcohol by altering the way the drug works or increase the risk for serious side effects. Please discuss with your doctor or pharmacist any potential food or alcohol interactions before using this drug.

What health conditions may interact with Lariam® (mefloquine HCL)?

Lariam® may interact with your health condition. This interaction may worsen your health condition or alter the way the drug works. It is important to always let your doctor and pharmacist know all the health conditions you currently have.

These health conditions are:

  • A history of seizures
  • Heart problems (e.g., irregular heartbeat)
  • Blood clotting problems
  • Liver problems
  • Diabetes
  • Mental or mood problems (e.g., depression)
  • Suicidal thoughts or actions


The information provided is not a substitute for any medical advice. You should ALWAYS consult with your doctor or pharmacist before using Lariam® (mefloquine HCL).

What is the dose of Lariam® (mefloquine HCL) for an adult?

Acute malaria infections

The recommended dose is 1250 mg PO once.

Malaria prevention

The recommended dose is 250 mg PO qWeek.

Start 1-2 weeks before arrival in endemic area; continue 4 weeks after leaving endemic area.

What is the dose of Lariam® (mefloquine HCL) for a child?

Acute malaria infections

The recommended dose for children more than 6 months old is 20-25 mg/kg PO as single dose or may divide in 2 doses.

Malaria prevention

The recommended dose for children from 5 to <10 kg is 31.25 mg (1/8 tablet) PO qWeek.

The recommended dose for children from 10 to <20 kg is 62.5 mg (1/4 tablet) PO qWeek.

The recommended dose for children from 20 to <30 kg is 125 mg (1/2 tablet) PO qWeek.

The recommended dose for children from 30-45 kg is 187.5 mg (3/4 tablet) PO qWeek.

The recommended dose for children >45 kg is 250 mg (1 tablet) PO qWeek.

Start 1-2 weeks before arrival in endemic area; continue 4 weeks after leaving endemic area.

How is Lariam® (mefloquine HCL) available?

Lariam® is available in the following dosage forms and strengths:

  • Lariam® tablet 250mg

What should I do in case of an emergency or overdose?

In case of an emergency or an overdose, call your local emergency services or go to your nearest emergency room.

What should I do if I miss a dose?

If you miss a dose of Lariam®, take it as soon as possible. However, if it is almost time for your next dose, skip the missed dose and take your regular dose as scheduled. Do not take a double dose.

Hello Health Group does not provide medical advice, diagnosis or treatment.

Review Date: February 17, 2017 | Last Modified: February 17, 2017

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