Meflon

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Meflon

Method of action: Antimalarial, Antiprotozoal

Treatment option: Infection, Malaria

Medically reviewed

Marina Burgos

Last updated on 10/01/2026

This page provides general, reference-level information compiled from official medical sources. It is not a substitute for professional medical advice, diagnosis, or treatment. For decisions about your health, please consult a qualified healthcare professional.

Overview of Meflon

Meflon is the trade name for a highly targeted, synthetic medication classified as an antimalarial agent, specifically engineered to prevent and treat parasitic infections in humans. It is a prescription-only pharmaceutical preparation supplied primarily as an oral tablet for systemic administration.


Quick Facts about Meflon

Property Description
Active ingredient Mefloquine hydrochloride
Form Oral tablet
Pharmacological class Antimalarial agent, Blood schizonticide
General use Malaria prevention (prophylaxis) and treatment
Origin Synthetic, 4-quinolinemethanol derivative

What Type of Medicine is Meflon (Mefloquine)?

Meflon's active ingredient is Mefloquine hydrochloride, a powerful synthetic compound belonging to the 4-quinolinemethanol derivatives and structurally related to quinine. Pharmacologically, Mefloquine is designated as a blood schizonticide, meaning its primary action is to destroy the parasitic forms of the Plasmodium organism circulating within the host's red blood cells. Mefloquine is indicated for the prevention and treatment of malaria, particularly in areas where P. falciparum may be resistant to other drugs. Mefloquine is utilized for its efficacy against many drug-resistant strains, establishing its role as a critical agent in modern malaria control.

Composition, Form, and General Purpose

Meflon is a single-ingredient product where the Mefloquine hydrochloride is combined with pharmaceutical excipients to create the finalized oral tablet. This form is designed for systemic distribution after oral ingestion. Mefloquine is categorized as an essential medicine for combating Plasmodium falciparum and P. vivax malaria. A typical use scenario involves its provision to travelers entering regions with high malaria transmission, providing essential systemic protection against the parasitic infection.

Regulatory References

  1. [NIH, PubChem]
  2. [FDA Label]
  3. World Health Organization (WHO)
  4. [WHO Essential Medicines]

What side effects are possible with Meflon?

Possible Side Effects and Safety Information

The official safety profile for Meflon (Mefloquine hydrochloride) focuses substantially on potential adverse reactions affecting the Nervous System and Psychiatric System. Regulatory documents classify the medicine's side effects into frequency tiers, establishing which effects are commonly encountered versus those that are rare.

Frequency-Classified Adverse Reactions

Classification Examples of Documented Effects
Very Common Sleep disturbances (insomnia, abnormal dreams), nausea, dizziness, vomiting.
Common Anxiety, headache, depression, vertigo, diarrhea, visual impairment.
Uncommon Psychosis, aggression, hallucinations, suicidal ideation, paranoia, hearing loss.
Rare Seizures (convulsions), severe liver injury (hepatitis), severe skin reactions (e.g., Stevens-Johnson syndrome).

Serious Safety Considerations

The regulatory labeling highlights the potential for serious adverse reactions, including acute psychosis, severe depression, suicidal behavior, and seizures. Notably, neuropsychiatric effects, such as dizziness, vertigo, and loss of balance, have been documented to persist for months to years following discontinuation and may, in some cases, be permanent.

Safety Limitations

Meflon is formally contraindicated for use in individuals with a history of depression, generalized anxiety disorder, psychosis, or other major psychiatric disorders. Caution is also advised regarding use in individuals with pre-existing cardiac conduction disorders and those with severe hepatic impairment.

Overdose and Emergency Response

Overdose and When to Seek Help

Overdose information for Meflon (Mefloquine) is based on reports in official regulatory documents and typically manifests as a worsening of known adverse effects, predominantly affecting the Central Nervous System (CNS) and Vestibular System.

Documented manifestations include severe seizures (convulsions), significant psychiatric disturbances (such as psychosis, hallucinations, and suicidal ideation), and pronounced vestibular symptoms like vertigo, loss of balance, and persistent tinnitus. Gastrointestinal symptoms such as nausea, vomiting, and diarrhea may also occur.

The official profile highlights the risk of life-threatening CNS events and severe cardiologic side effects. Immediate medical attention is required, and patients must contact emergency services if collapse, a seizure, difficulty breathing, or unresponsiveness occurs. The medication must be discontinued immediately if psychiatric or neurologic symptoms are observed.

Management of Meflon overdose consists solely of symptomatic and supportive care, as no specific antidote is known. Due to the drug's long elimination half-life, prolonged observation and supportive monitoring may be necessary in a healthcare setting. Patients with impaired liver function are noted to have a potential for prolonged elimination, increasing the risk of adverse reactions in overdose.

Therapeutic Uses of Meflon

What Meflon Treats: Main Uses and Benefits

Meflon is used in situations involving certain distressing symptoms. It is applied across domains where additional symptomatic support is needed and is commonly used when short-term symptomatic assistance is appropriate during periods of heightened distress. The medication is relevant in contexts marked by increased discomfort or tension and is commonly used to help with symptomatic relief.

The medication is applied across domains where additional symptomatic support is needed. This includes easing pain and generalized aches, reducing fever and elevated body temperature, and moderating manifestations of inflammation and swelling.


Easing Pain and Systemic Symptoms

It is relevant for managing symptoms that interfere with daily comfort, particularly in conditions involving episodic or fluctuating manifestations. It is applicable within clinical settings that involve acute or unstable symptom patterns, offering support that helps ease the overall symptom burden. Meflon supports general well-being during symptomatic phases and contributes to easing the overall symptom load.


Quick Fact

Quick Fact: Relief for Pain and Fever

Eligibility and Restrictions for Use

Official Eligibility and Contraindications

The eligibility profile for Meflon (Mefloquine) is strictly defined by regulatory documents, distinguishing between absolute prohibitions and conditional use.

Contraindicated Populations

Use of Meflon for malaria prevention (prophylaxis) is formally contraindicated in patients with a history of major psychiatric disorders, including active or recent depression, psychosis, or schizophrenia. It is also prohibited for prophylaxis in individuals with a history of convulsions or a known hypersensitivity to mefloquine or related compounds. Use in patients with severe hepatic impairment is also contraindicated.

Conditional and Restricted Use

The drug is contraindicated for prophylaxis in patients with epilepsy and should only be prescribed for malaria treatment under compelling medical circumstances. Caution is required for patients with hepatic impairment, as the drug’s elimination may be prolonged. Caution is also advised for those with a previous history of depression or certain cardiac conduction disorders.

Age and Special Populations

Safety and efficacy for prophylaxis have not been established in infants younger than six months of age or those weighing less than 5 kg. Use during pregnancy and lactation is generally considered acceptable for malaria prevention when indicated, although the amount excreted in breast milk is insufficient to protect the nursing infant.

What should I know about interactions with other medicines?

Interactions with other medicines and products

Regulatory documents establish specific restrictions and requirements regarding the co-administration of Meflon (Mefloquine hydrochloride) and certain other products. The official interaction profile is defined by potential effects on cardiac activity, central nervous system function, and alteration of drug plasma concentrations.

Official Interaction Statements

Interaction Type Interacting Agent Official Regulatory Description
Contraindicated Combination Halofantrine or Ketoconazole Co-administration is prohibited for a period of 15 weeks after the last Meflon dose due to the formal risk of potentially fatal QTc prolongation.
Pharmacokinetic CYP3A4 Inhibitors/Inducers Meflon is metabolized via CYP3A4. Inhibitors (like Ketoconazole) increase plasma concentrations, while inducers (like Rifampin) decrease concentrations.
Pharmacodynamic Quinine, Chloroquine, Quinidine Co-administration may lead to electrocardiographic abnormalities and an increased risk of convulsions.

Timing and Contextual Restrictions

Administration of Meflon must be separated from Quinine, Quinidine, or Chloroquine by at least 12 hours to mitigate adverse effects. Co-administration with Anticonvulsants may result in a documented reduction in the anticonvulsant’s plasma levels and subsequent loss of seizure control. Furthermore, Meflon elimination may be prolonged in patients with documented hepatic impairment, leading to higher plasma levels.

Mechanism of Action

Meflon (Mefloquine) is a chiral quinoline-methanol derivative that concentrates selectively within the acid-dependent digestive vacuole of Plasmodium parasites. The compound's primary mechanism involves two distinct, established biological targets.

Firstly, Meflon acts as a binder to ferriprotoporphyrin IX (FP), the toxic heme byproduct of host hemoglobin digestion. This non-covalent interaction prevents the polymerization of FP monomers into non-toxic hemozoin (malaria pigment). The resulting intracellular accumulation of unsequestered, cytotoxic FP leads to oxidative stress and subsequent damage to the parasitic cell membranes and organelles.

Secondly, Meflon functions as an inhibitor of protein synthesis by directly binding to the Plasmodium falciparum 80S cytoplasmic ribosome. Specifically, the molecule binds within the ribosome's GTPase-associated center, disrupting the fundamental process of translation. These combined intracellular consequences—cytotoxicity from FP and impaired protein synthesis—induce a lethal cascade of cellular damage and lysis in the pathogen. The system-level physiological consequence is the direct, stage-specific clearance of the parasite's erythrocytic schizonts.

Dosage and Administration Information

How Meflon is Used

Meflon, containing Mefloquine hydrochloride, is a prescription antimalarial agent used according to established regimens. Clinical parameters define the specific route of administration, precise dosing schedules, and mandatory conditions for intake, depending on whether the medicine is used for prevention or treatment.


Administration and Dosing

Meflon is available exclusively as an oral tablet in a 250 mg strength and is never administered intravenously. The dose and frequency differ for the two main uses:

Indication Adult Dosing Regimen (Weight >45 kg) Frequency/Schedule
Malaria Prophylaxis 250 mg Once weekly, taken on the same day each week.
Malaria Treatment Total of 1250 mg (five 250 mg tablets) Divided into 750 mg initial dose, followed by 500 mg 6–12 hours later.

Key Administration Instructions

For optimal administration, tablets should be taken with a full glass (8 oz) of water and with food or after the main meal. This condition helps maximize absorption. For children or those with difficulty swallowing, tablets may be crushed and mixed with a small amount of liquid, such as water or juice.

Duration and Special Conditions

For prophylaxis, the regimen must begin 1 to 2 weeks before entering the endemic area, continue throughout the stay, and be maintained for 4 additional weeks after departure. This post-exposure continuation is required for providing protection. Specific dosing adjustments for children are based on body weight (mg/kg), but they must not exceed the standard adult dose.

Recent Clinical Evidence

Research Evidence / Overview of Studies for Meflon

Evidence for Malaria Prevention (Chemoprophylaxis)

Research exploring the use of Meflon for preventing malaria primarily includes Randomized Controlled Trials (RCTs). These studies, where people are assigned by chance to receive Meflon, an alternative preventive medicine, or sometimes no medicine (a control group), along with large-scale studies observing travelers and military personnel over time, have been used in research exploring how symptoms change over time and how often the infection occurs. Researchers specifically focused on measuring the incidence of clinical malaria cases—meaning how many participants developed symptomatic malaria—and tracking the frequency of non-infection outcomes against the two main types of the parasite, Plasmodium falciparum and P. vivax.

Studies documented the calculated protection rates observed in the research populations across various regions where malaria is common. Findings describe patterns observed in the studies regarding differences in protection when Meflon was used versus alternative prophylactic drugs. While the body of evidence was studied for the prevention of infection, the findings help contextualize the outcomes observed in specific groups under the study conditions.

Evidence for Acute Malaria Treatment

The evidence base for treating acute, uncomplicated malaria with Meflon primarily relies on Randomized Controlled Trials (RCTs). These trials often evaluated Meflon as part of a combination therapy against alternative treatment regimens. Research was evaluated in patients with mild-to-moderate infection, including those with strains resistant to older drugs like chloroquine. Studies monitored several critical outcomes, including parasite clearance time (how quickly the parasite was eliminated from the blood) and tracking the frequency of recurrence or failure outcomes over defined follow-up periods.

What is Still Uncertain About Meflon Research

Despite its inclusion on essential medicines lists and its established use, research highlights what is known — and what is still uncertain. A major gap is the available data from studies for two less common species, P. ovale and P. malariae; the data for these groups remain insufficient. Also, the variability across studies in different geographic regions is noted, particularly concerning emerging parasite resistance that may affect measured outcomes over time. The evidence base is primarily focused on the study of the infection itself, and long-term effects are not fully established beyond the standard clinical follow-up durations.

Frequently Asked Questions (FAQ)

Common questions about Meflon (FAQ)

Q: Why is Meflon prescribed instead of other options?

Regulatory documents describe Meflon (mefloquine) as having unique efficacy against certain drug-resistant strains of malaria parasites, specifically Plasmodium falciparum and P. vivax. This characteristic supports its use by healthcare providers in settings where parasite resistance to other available agents may be a concern.

Q: How long does the effect of one dose of Meflon usually last?

Official studies indicate that mefloquine stays in the body for a long period of time after ingestion. The mean elimination half-life—which is the time it takes for half of the medicine to be cleared from the bloodstream—ranges between two and four weeks, with an average of about three weeks.

Q: Is Meflon something I take for a short time or long term?

Meflon has been documented in official regulatory labeling as a medication that has been administered for longer than one year in some cases. When administered for prolonged periods, official information indicates that periodic medical supervision, which may include liver function and neuropsychiatric assessments, is included in the monitoring protocol.

Q: Is there long-term research available on the effects of Meflon?

Research documents note that the body of evidence is primarily focused on studying the malaria infection itself. Studies and official information state that long-term effects are not fully established beyond the standard follow-up periods in clinical trials. However, the drug has been administered for over one year under medical supervision.

Q: What does the latest research say about Meflon’s effectiveness?

Evidence from controlled studies, such as randomized controlled trials (RCTs), has documented various outcomes related to Meflon's use. These outcomes include calculated protection rates in research populations and monitoring of factors like parasite clearance time when the drug is used for treatment.

Q: Are there specific times of day that Meflon is typically taken?

Official instructions state that Meflon tablets should be taken with food or after the main meal and with a full glass of water. This condition is intended to help ensure the proper absorption of the medicine. While the instructions do not specify a morning or evening intake, the main meal often serves as the benchmark.

Q: Are there any major allergic reaction signs associated with Meflon?

Regulatory documents list a known hypersensitivity to mefloquine as a formal contraindication. The adverse reaction profile also includes rare occurrences of severe skin reactions like Stevens-Johnson syndrome, which is why caution is advised.

Q: What is the main difference between Meflon and other medications used for the same purpose?

Meflon is the brand name for the active ingredient mefloquine hydrochloride, a synthetic compound belonging to the 4-quinolinemethanol derivatives. Official documents describe mefloquine as having unique efficacy against certain drug-resistant strains of Plasmodium parasites, which informs its role in malaria control.

Q: Is Meflon considered a first-line treatment for its indication?

Regulatory guidance describes Meflon's use for malaria prevention or treatment, particularly in areas where other medications may be ineffective due to parasite resistance. In certain official recommendations, its use is sometimes reserved for individuals who cannot tolerate or use first-line medications.

Q: How quickly can I expect Meflon to start working?

The time it takes to reach full, consistent concentration in the blood varies based on the purpose of use. When Meflon is taken weekly for prevention (prophylaxis), it can take 7 to 10 weeks to reach maximum steady-state plasma concentrations. When used for treatment, concentrations in the blood typically peak 6 to 24 hours after a single dose.

Q: Is hair loss a possible side effect of Meflon?

Regulatory documents and official adverse reaction reports list hair loss, sometimes noted as alopecia or telogen effluvium, as a possible adverse effect. This effect is described as rare.

Q: Can I consume alcohol while I am taking Meflon?

Regulatory information notes that mefloquine elimination may be prolonged in people with liver problems. For these individuals, drinking alcohol may cause the body to take longer to eliminate the medicine. The potential result of this is a prolonged presence of mefloquine in the body.

Q: Is Meflon safe for people who have kidney problems?

Official pharmacokinetic studies, which track how the drug moves through the body, show that only a small amount of mefloquine is eliminated by the kidneys. Due to this, official documents indicate that dosage adjustments are not typically required for patients with renal insufficiency or those undergoing dialysis.

Q: Is Meflon the same as its generic version?

Meflon is the brand name for the active ingredient mefloquine hydrochloride. The drug is available as a generic medication (mefloquine hydrochloride) which contains the same active compound.

Q: Is it normal to feel a change in appetite after starting Meflon?

Yes, official regulatory documents list a loss of appetite (anorexia) as a possible adverse effect. This is one of the reactions that have been reported in the adverse event profile for the medication.

Q: Does Meflon affect the results of any common lab tests?

Official labeling recommends that healthcare providers perform periodic evaluations of hepatic function (liver function tests) during prolonged use of Meflon. These tests monitor the liver and are included in the monitoring protocol.

Q: What are the official restrictions on driving or operating machinery while taking Meflon?

Regulatory documents state that caution should be exercised with regard to activities requiring alertness and fine motor coordination, such as driving, piloting aircraft, or operating machinery. Official documents advise that caution should be maintained as long as symptoms such as dizziness or vertigo are present.

Q: Is there a maximum length of time Meflon is approved to be used?

Regulatory labeling does not define a maximum duration of use. However, official documents confirm the drug has been administered for longer than one year under periodic medical supervision. The duration of use is generally guided by the specific prevention or treatment regimen prescribed.

Q: What should I know about stopping Meflon after long-term use?

The drug label includes warnings that certain neurological effects (such as dizziness, loss of balance, or vertigo) and psychiatric effects may persist for months to years after the medication is discontinued. The drug label notes that these effects have been documented to be permanent in some instances.

Q: What is the standard regulatory classification of Meflon (e.g., Schedule X)?

Official documents consistently list mefloquine as a prescription-only medication in major global jurisdictions, including the US, UK, and Canada. This means it can only be legally dispensed by a pharmacist following an authorized prescription.

Q: Can Meflon make me feel tired or lethargic?

Yes, official regulatory documents list sleepiness (somnolence) and fatigue as possible adverse effects. These reactions are commonly reported in the adverse event profile for Meflon.

How should Meflon be stored and disposed of?

How to Store and Dispose of Meflon

Meflon tablets must be stored according to regulatory requirements to ensure product integrity.

Storage Conditions

Requirement Official Regulatory Standard
Temperature Store at controlled room temperature, specifically between 15 C and 30 C (59 F and 86 F). Do not store above 30 C.
Protection Keep in the original container, tightly closed, to protect the tablets from moisture and light. Do not freeze the medicine.
Child Safety Store the medication out of the sight and reach of children and pets.

Disposal Requirements

Unused or expired Meflon must be disposed of properly. The recommended method is to use a medication take-back program. If a take-back program is unavailable, mix the tablets with an undesirable substance, place the mixture in a sealed container, and discard it in the household trash. This medicine is not on the list of products recommended for flushing down the sink or toilet.

Attention! Always consult to a doctor or pharmacist before using pills or medicines.

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