Which Malaria Prevention Drug Is Right for You? A Traveller's Guide

Choosing the wrong antimalarial is the single most preventable mistake travellers make. Here is how to match the drug to your trip, your health, and your destination.

Malaria prevention: picking the right drug before you fly

According to the WHO World Malaria Report 2024, 83 countries reported approximately 263 million infections and 597,000 deaths in 2023. Travellers are not immune to those numbers. The decision that matters most is not whether to take prophylaxis, but which prophylactic drug is right for your specific trip.^[1]

This guide covers the four main chemoprophylaxis options, when each is appropriate, their real-world trade-offs, and the non-drug protection measures that no drug can replace. It also addresses the questions travellers search for but rarely get direct answers to.

Medical disclaimer: This article is for informational purposes only and does not constitute medical advice. Malaria prophylaxis must be tailored to your destination, health history, and current medications. Always consult a travel medicine specialist or your prescribing clinician before starting or changing any antimalarial regimen.

Why the destination decides the drug

No single antimalarial works everywhere. Across sub-Saharan Africa and parts of South and Southeast Asia, chloroquine monotherapy may be ineffective for those destinations. Mefloquine resistance exists in limited rural border areas of Thailand, Cambodia, and Myanmar.^[2]

The CDC publishes a country-by-country malaria chemoprophylaxis table updated at least annually. Checking the current table for your specific region before your appointment is the single most useful preparation step.^[3]

The four main prophylaxis drugs compared

Atovaquone-proguanil (Malarone)

Atovaquone-proguanil is widely prescribed and considered the best-tolerated option overall. It starts just one to two days before travel and stops seven days after leaving the endemic area, which is a significant advantage over mefloquine and doxycycline. That short post-travel tail makes it the default recommendation for shorter trips.^[4]

The main trade-off is cost. Generic atovaquone-proguanil remains more expensive per tablet than doxycycline, and for trips lasting three months or longer, the cost difference becomes substantial. It is also not recommended for people with severe renal impairment.

Doxycycline

Doxycycline is the most cost-effective daily option for long trips. It also covers additional travel infections including some Rickettsiae species and leptospirosis, which makes it a reasonable choice for trekking and adventure itineraries involving freshwater exposure.

The downsides are real. It must continue for four weeks after leaving the malarious area, it cannot be used in pregnancy or in children under eight years, and it increases photosensitivity, which is a practical concern in tropical climates. People prone to vaginal yeast infections when taking antibiotics should discuss alternatives with their clinician.

Mefloquine

Mefloquine's weekly dosing is convenient, but its safety profile is genuinely complicated. The FDA includes a boxed warning that mefloquine may cause neuropsychiatric adverse reactions that can persist after the drug has been discontinued. Reported effects include anxiety, depression, vivid dreams, and in rare cases psychosis or seizures.^[5]

Mefloquine is contraindicated in people with active depression, a recent history of depression, generalised anxiety disorder, psychosis, schizophrenia, other major psychiatric disorders, or seizures. If you have any of those conditions, discuss alternatives before your travel appointment. Starting mefloquine at least two weeks before departure allows time to detect intolerance early.^[5]

Primaquine and tafenoquine

Primaquine and tafenoquine are causal prophylactics: they act on liver-stage parasites, meaning they eliminate dormant hypnozoites that cause relapses of Plasmodium vivax and Plasmodium ovale. Both require a G6PD (glucose-6-phosphate dehydrogenase) test before use, as they can trigger life-threatening haemolytic anaemia in G6PD-deficient individuals.^[6]

Tafenoquine has a simpler schedule than primaquine: daily for three days before travel, weekly during travel, then a single dose one week after leaving. For short trips to high-risk destinations, this is an option worth discussing with a travel medicine clinician.

The timing trap most travellers fall into

Antimalarial drugs do not prevent the parasite from entering your body. They suppress or eliminate it during early blood or liver stages. Some medications require patients to start them weeks in advance of travel, and stopping too soon after leaving exposes you to delayed-onset illness.^[3]

Atovaquone-proguanil and doxycycline can start one to two days before departure. Mefloquine should start one to two weeks before. The post-travel tail is seven days for atovaquone-proguanil, but four weeks for both doxycycline and mefloquine. Stopping early is one of the most common reasons prophylaxis fails.

Non-drug protection: what drugs cannot cover

No antimalarial drug is 100% protective. Using multiple prevention strategies together offers additional protection. The Anopheles mosquito that carries malaria bites predominantly between dusk and dawn, so the hours you spend unprotected in the evening carry the greatest risk.^[7]

Practical measures that matter:

DEET-based repellents at 30-50% concentration are the most evidence-backed insect repellents for malaria-endemic areas. Apply to exposed skin after sunscreen.
Permethrin-treated clothing and sleeping gear reduces biting risk significantly in field conditions, and the treatment remains effective through several washes.
An intact, permethrin-treated bed net is non-negotiable in rural guesthouses and any accommodation without functioning air conditioning and window screens.
Long-sleeved, loose-fitting clothing in light colours worn from dusk onwards limits exposed skin during peak biting hours.

Refer to our mosquito protection guide for travellers for more information on such measures.

Standby emergency treatment: when to carry a backup course

Standby emergency treatment (SBET) means carrying a full treatment course of an antimalarial to use if you develop fever symptoms and cannot reach medical care within 24 hours. Travellers who are not taking atovaquone-proguanil for prophylaxis can use it as their standby treatment. SBET is not a substitute for seeking medical review; it buys time when care is not immediately accessible.^[8]

SBET is most relevant if your itinerary includes remote areas in high-transmission regions such as Papua New Guinea, rural sub-Saharan Africa, or border regions of Cambodia, Laos, or Myanmar, where access to a clinic within hours cannot be guaranteed.

Buying antimalarials abroad: the counterfeit risk

The temptation to buy antimalarials locally is understandable: they are cheaper. The risk is counterfeit medication. WHO and numerous field studies have documented substandard or falsified antimalarials in local markets in Cambodia, Myanmar, and across parts of sub-Saharan Africa. A pill that looks right but contains no active ingredient offers no protection.

Obtain your full prophylaxis supply from a regulated pharmacy or travel clinic before departure. Bring more than you expect to need. Running out mid-trip and sourcing locally carries a real risk of receiving a product that fails when it matters most.

Symptoms after returning: the delayed-onset trap

Malaria can present weeks or even months after leaving an endemic area. Several hundred cases of late-onset Plasmodium vivax or Plasmodium ovale relapses occur each year in returned travellers who adhered correctly to their prescribed regimen. This is not prophylaxis failure in the traditional sense; these are relapses from dormant liver-stage parasites.^[2]

If you develop fever, chills, or flu-like illness within a year of returning from a malaria-endemic region, tell any doctor or emergency clinician you see, even if you completed your prophylaxis. Malaria is easily missed when clinicians do not know about the travel history.

Keeping your medical records accessible while you travel

If you are hospitalised abroad with a febrile illness, the treating clinician needs to know your prophylaxis drug, dose, and duration immediately. An International Patient Summary stored on Nomedic includes your current medications, allergies, and relevant conditions in a format readable by clinicians internationally. It takes minutes to set up and removes a critical communication gap in an emergency.

Pair this with comprehensive travel insurance that explicitly covers tropical diseases and medical evacuation. Malaria treatment in a private hospital in Kenya, Tanzania, or Papua New Guinea can cost several thousand US dollars before evacuation costs are considered.

Frequently asked questions

Is malaria prophylaxis legally required to enter any country?

No country currently requires proof of malaria prophylaxis as a condition of entry, in the way yellow fever vaccination is required for some destinations. Taking prophylaxis is a personal health decision, not an immigration requirement. Requirements for yellow fever vaccination, however, do apply to entry into several countries and are a separate matter.

Can I get Malarone (atovaquone-proguanil) over the counter in Thailand or Kenya?

In Thailand and Kenya, atovaquone-proguanil may be available at pharmacies without a formal prescription in practice, but quality and authenticity of locally sourced antimalarials cannot always be verified. Obtaining your full supply from a regulated pharmacy or travel clinic at home before departure eliminates the counterfeit risk and ensures you have the correct formulation.

What happens if I forget to take my malaria tablet while travelling?

For daily regimens such as atovaquone-proguanil and doxycycline, take the missed dose as soon as you remember, then continue at the regular time. For mefloquine, which is weekly, take the missed dose as soon as possible. Missing doses consistently reduces the protective effect, so setting a phone alarm for the same time each day or each week is a practical safeguard.

Does doxycycline for malaria interact with the contraceptive pill?

Current evidence does not support a clinically significant interaction between doxycycline and combined oral contraceptives. Earlier concerns about antibiotic interference have largely been revised. However, always disclose all medications you take to your prescribing clinician before starting any antimalarial so they can review your full medication list.

Is malaria prophylaxis safe in the first trimester of pregnancy?

Mefloquine is not recommended in the first trimester. Doxycycline is contraindicated throughout pregnancy. Atovaquone-proguanil has limited safety data in pregnancy and is generally avoided unless the risk of malaria clearly outweighs the risk. Chloroquine is considered the safest option in areas where it remains effective, but chloroquine resistance is now widespread. Pregnant travellers should consult a specialist before visiting any malaria-endemic region.

Can malaria tablets give you anxiety or depression?

Mefloquine carries an FDA boxed warning for neuropsychiatric adverse reactions including anxiety, depression, vivid dreams, and in rare cases psychosis or seizures, and these effects can persist after the drug is stopped. Atovaquone-proguanil and doxycycline do not carry the same neuropsychiatric warnings. If you have a history of anxiety, depression, or any psychiatric condition, mefloquine should be avoided and alternatives discussed with your clinician.