O que é Lariam?
Lariam is the brand name for Mefloquine, a quinoline-methanol antimalarial medicamento first developed in the 1970s for use against Chloroquine-resistant strains of Plasmodium falciparum. Lariam has historically been widely prescribed for malaria prophylaxis due to its convenient once-weekly dosing schedule and efficacy against resistant malaria strains.
However, Lariam carries a well-established and significant risk of neuropsychiatric adverse effects — including anxiety, depression, hallucinations, and in rare cases, psychosis — which has led to updated prescribing guidance from the Agência Europeia de Medicamentos (EMA) and regulatory agencies worldwide. As a result, Lariam is now generally considered a second-line option for malaria prophylaxis, reserved for cases where alternative medicamentos (Malarone or Doxycycline) are not suitable.
Como funciona Lariam work?
The exact mechanism of action of Mefloquine is not fully understood. It is believed to act by interfering with haem detoxification within the malaria parasite’s food vacuole, similar in some respects to Chloroquine, but Mefloquine retains activity against Chloroquine-resistant strains due to structural differences.
Mefloquine is a blood-stage antimalarial — it acts on the asexual stages of Plasmodium parasites once they have entered the bloodstream. It does not eliminate dormant liver-stage parasites (hypnozoites) of P. vivax or P. ovale.
Lariam’s long half-life of approximately 2–3 weeks means it persists in the body for an extended period, which accounts for both its once-weekly dosing convenience and the prolonged duration of efeito secundários if they occur.
Para quem é Lariam for?
Given its risk profile, Lariam is generally considered appropriate only when:
- Malarone (Atovaquone/Proguanil) and Doxycycline are contraindicated or not tolerated
- Travel is to a region with high-risk P. falciparum malaria where Mefloquine remains effective (not applicable in parts of Southeast Asia with documented Mefloquine resistance)
- The paciente has no personal or family history of psychiatric disorders, seizures, or cardiac conduction abnormalities
Lariam may be considered for:
- Travel to sub-Saharan Africa (excluding areas with documented Mefloquine resistance)
- Long-duration travel where once-weekly dosing provides a practical advantage
- Travellers who cannot take daily medication reliably
Lariam is not recommended for travel to:
- Areas of Southeast Asia with documented Mefloquine resistance (particularly Thailand-Myanmar and Thailand-Cambodia borders)
- Areas where first-line alternativas are equally accessible
Dosagem
For malaria prophylaxis in adults, the EMA-approved schedule is:
| Phase | Adult Dose | Timing |
|---|---|---|
| Pre-travel loading | 250 mg once weekly | Start 2–3 weeks before departure |
| During travel | 250 mg once weekly | Continue throughout stay |
| Post-travel | 250 mg once weekly | Continue for 4 weeks after leaving risk area |
Starting Lariam 2–3 weeks before departure (rather than 1–2 weeks as with some other antimalarials) is specifically recommended to allow identification of any neuropsychiatric efeito secundários before travel begins, enabling a switch to an alternative if needed.
Lariam should be taken with food and a full glass of water, on the same day each week.
Efeitos secundários
Neuropsychiatric efeito secundários (EMA Black Box Warning)
Mefloquine can cause serious neuropsychiatric adverse events. These may include:
- Vivid or disturbing dreams, nightmares
- Insomnia or other sleep disturbances
- Anxiety, agitation, or restlessness
- Depression
- Mood changes
- Paranoia or unusual suspicion
- Hallucinations (auditory or visual)
- Confusion or disorientation
- Suicidal ideation (rare)
In rare cases, psychosis has been reported. The EMA has mandated that these risks be clearly communicated to pacientes receiving Lariam. Any neuropsychiatric symptoms should be reported to a médico immediately. The long half-life of Mefloquine means that symptoms can persist for weeks after the last dose.
Efeitos secundários comuns
- Nausea, vomiting, abdominal pain
- Dizziness or vertigo
- Headache
- Diarrhoea
- Fatigue
Serious but less common efeito secundários
- Cardiac effects: Bradycardia (slowing of the heart), QT prolongation — relevant for pacientes with existing cardiac conditions
- Seizures: Risk is elevated in pacientes with a personal or family history of epilepsy
- Vestibular effects: Persistent dizziness or balance problems, which may continue after stopping the medicamento
Lariam vs alternativas
| Medicine | Dosing | Neuropsychiatric Risk | SE Asia Use | Post-travel |
|---|---|---|---|---|
| Lariam (Mefloquine) | Weekly | Significant (EMA black box) | Limited (resistance) | 4 weeks |
| Malarone | Daily | Minimal | Yes | 7 days |
| Doxycycline | Daily | Minimal | Yes | 4 weeks |
| Chloroquine | Weekly | Minimal | Not recommended (resistance) | 4 weeks |
Como obter Lariam online na Europa
Lariam is a medicamento sujeito a receita médica in all estados-membros da UE. Prescrivia operates as a technology intermediary — we do not prescribe medicamentos, employ médicos, or sell medicamentos. Our platform connects pacientes with independent EU-registered médicos who can conduct online travel health assessments.
Due to Lariam’s significant neuropsychiatric risk profile, médicos conducting assessments will pay particular attention to:
- Any personal or family history of psychiatric illness
- History of seizures or epilepsy
- Cardiac history
- Current medications that may interact with Mefloquine
The process:
- Complete a travel health assessment: Provide full details of your destination, travel dates, and medical and psychiatric history.
- Avaliação médica: An independent EU-registered médico reviews your assessment and determines whether Lariam or an alternative antimalarial is most appropriate.
- Receita e dispensa: If a receita médica is issued, it is forwarded to a licensed EU farmácia partner for dispensing and delivery.
Important: A Prescrivia não garante that a receita médica will be issued. All prescribing decisions are made independently by qualified medical professionals.
Informação de segurança importante
Do not take Lariam if you have:
- A personal or family history of psychiatric disorders (depression, anxiety, psychosis, bipolar disorder)
- A history of epilepsy or seizures
- Cardiac conduction abnormalities (e.g., QT prolongation, heart block)
- Known hypersensitivity to Mefloquine or quinine
- Are in the first trimester of pregnancy
Stop Lariam immediately and seek medical advice if you develop:
- Anxiety, depression, restlessness, or confusion
- Unusual or vivid dreams, hallucinations
- Palpitations, fainting, or chest pain
- Severe dizziness or balance problems
Informe o seu médico if you are taking:
- Other medicamentos that affect the heart rhythm (QT-prolonging drugs)
- Antiepileptics
- Beta-blockers or other antihypertensives
- Halofantrine (severe cardiac interaction — do not combine)
Fontes
Medical information on this page is based on the following sources:
- Agência Europeia de Medicamentos (EMA). Lariam (Mefloquine) — Summary of Product Characteristics. ema.europa.eu
- Organização Mundial da Saúde (WHO). International Travel and Health: Malaria. who.int
- EMA. PRAC recommends updating the warnings for mefloquine-containing medicamentos. EMA/PRAC signal. 2013.
- Nevin RL. Mefloquine and posttraumatic stress disorder: a causal association. Curr Psychiatry Rep. 2014.
This content is provided for informational purposes only and does not constitute medical advice. Always consult a qualified healthcare professional for travel health advice specific to your circumstances.
Frequently asked questions
- O que é Lariam utilizado para?
- Lariam (Mefloquine) is an antimalarial medicamento utilizado para the prevention and tratamento of malaria, including malaria caused by Chloroquine-resistant strains of Plasmodium falciparum. It is taken once weekly and is one of three main antimalarial prophylactics recommended for travellers to high-risk malaria areas.
- What are the neuropsychiatric efeito secundários of Lariam?
- Lariam carries a well-documented risk of neuropsychiatric efeito secundários, which include vivid dreams, insomnia, anxiety, depression, paranoia, hallucinations, and in rare cases, more severe psychiatric events. The EMA requires Lariam to carry a black box warning about these risks. Any neuropsychiatric symptoms should be reported to a médico immediately and the medicamento stopped.
- Who should not take Lariam?
- Lariam is contraindicated in people with a history of psychiatric illness (including depression, anxiety disorders, or psychosis), epilepsy or seizure disorders, cardiac conduction abnormalities, and known hypersensitivity to Mefloquine or related compounds. It is generally not recommended as first-line for most travellers given the risk profile.
- How early before travel should I start Lariam?
- Lariam should ideally be started 2–3 weeks before departure to a malaria-risk area. Starting early allows any neuropsychiatric efeito secundários to become apparent before travel begins, giving time to switch to an alternative antimalarial if needed.
- Posso obter Lariam online na Europa?
- You can access Lariam through online intermediary platforms that connect you with independent EU-registered médicos. Due to the serious risk profile of Mefloquine, médicos conduct a thorough assessment of your psychiatric history and overall health before determining whether it is appropriate for you.
Tratamentos
A Prescrivia é apenas uma plataforma intermediária. Não prestamos serviços médicos, não prescrevemos tratamentos nem dispensamos medicamentos. Todas as decisões médicas são tomadas por médicos independentes registados na UE. Todos os medicamentos são dispensados por farmácias licenciadas na UE. Esta plataforma facilita a ligação entre pacientes e prestadores de cuidados de saúde.