Walk into a Spanish farmacia and ask for malaria tablets, and you will be told the same thing every time: these are prescription-only medications. The pharmacist cannot sell you atovaquone/proguanil, doxycycline, or mefloquine without a receta médica — a valid prescription issued by a doctor registered in Spain. That is the law, and no amount of explaining that you are flying to sub-Saharan Africa tomorrow will change it.
How Does Malaria Spread — and How Do Tablets Prevent It?
Malaria is caused by Plasmodium parasites — single-celled organisms transmitted to humans through the bite of an infected female Anopheles mosquito. Five species of Plasmodium cause human malaria, but Plasmodium falciparum is responsible for the vast majority of severe cases and deaths. The World Health Organization recorded approximately 263 million malaria cases and 597,000 deaths globally in 2023, with over 90% of those in sub-Saharan Africa.[1]
When an infected mosquito bites you, parasites enter your bloodstream and travel to the liver. There, they multiply silently for seven to thirty days — this is the incubation period, during which you feel completely fine. Once the parasites leave the liver and invade your red blood cells, they multiply further, rupturing the cells and releasing more parasites into the bloodstream in waves. That cyclical destruction of red blood cells is what produces the classic pattern of high fever, shaking chills, and drenching sweats that defines malaria.[2]
Antimalarial tablets work by targeting the parasite at different stages of this lifecycle. Atovaquone/proguanil, for example, disrupts the parasite's ability to produce energy inside both the liver and the red blood cells, killing it before it can establish a full infection. Doxycycline interferes with the parasite's protein production, stopping it from replicating. These medications do not prevent the mosquito from biting you — they prevent the parasite from surviving inside your body after a bite occurs.[3]
Spain itself has no malaria transmission. The reason you are reading this article is most likely that you are in Spain — on holiday, on business, or in transit — and you are about to travel onward to a country where malaria is endemic. Common routes from Spain include flights to West and East Africa, the Indian subcontinent, Southeast Asia, and parts of Central and South America. If your destination falls within a malaria-risk zone, you need prophylactic medication, and you need to start it before you arrive.
Which Malaria Tablets Should You Take?
Three antimalarial medications are routinely prescribed for travellers. The choice between them depends on your destination, the length of your trip, your medical history, and your tolerance for potential side effects. All three require a prescription in Spain.
Atovaquone/Proguanil (Malarone)
Atovaquone/proguanil is the most commonly prescribed antimalarial for short-to-medium trips. It works by blocking the parasite's mitochondrial electron transport chain (its energy supply) while simultaneously inhibiting an enzyme the parasite needs to replicate its genetic material. This dual mechanism makes it highly effective against P. falciparum, the most dangerous malaria species. Clinical trials show a protective efficacy above 95% when taken correctly.[3] It is generally well tolerated, with the most common side effects being mild nausea, headache, and abdominal pain in a small percentage of users.
Doxycycline
Doxycycline is a tetracycline-class antibiotic that also has strong antimalarial properties. It inhibits the parasite's ability to produce essential proteins, effectively stopping it from multiplying in your bloodstream. It is significantly cheaper than atovaquone/proguanil, making it a common choice for longer trips. The main trade-off is sun sensitivity — doxycycline makes your skin more prone to sunburn, which is relevant if you are heading to a tropical destination. Other potential side effects include stomach upset (reduced by taking it with food) and, in women, an increased risk of vaginal yeast infections.[4]
Mefloquine (Lariam)
Mefloquine is taken once per week rather than daily, which makes it convenient for very long trips. It disrupts the parasite's ability to process haemoglobin — the molecule it feeds on after invading your red blood cells. Mefloquine is effective in most malaria-endemic regions, but it is less commonly prescribed today because of its neuropsychiatric side-effect profile. Some users experience vivid dreams, anxiety, dizziness, or mood changes. Serious psychiatric reactions are rare but documented, and the drug is not suitable for people with a history of depression, anxiety disorders, or seizures.[5]
What Does Malaria Look Like If You Are Not Protected?
Understanding what malaria actually does to the body is part of understanding why prophylaxis is non-negotiable. The initial symptoms often mimic a bad flu: high fever (frequently above 39°C/102°F), shaking chills, heavy sweating, headache, muscle aches, and fatigue. These symptoms typically appear 7 to 30 days after the infectious bite, though in some cases they can be delayed for months — particularly with P. vivax and P. ovale, which can lie dormant in the liver.[2]
With P. falciparum — the species dominant in sub-Saharan Africa and the one most likely to kill — the disease can progress rapidly from flu-like symptoms to life-threatening complications within 24 to 48 hours. These complications include cerebral malaria (seizures, confusion, coma), severe anaemia from massive red blood cell destruction, respiratory distress, kidney failure, and hypoglycaemia (dangerously low blood sugar). Pregnant women and young children face the highest risk of severe outcomes, but healthy adults with no prior malaria exposure are also highly vulnerable because they have no partial immunity.[1]
A single mosquito bite on your first evening is enough to transmit malaria. The parasite needs no minimum exposure time — and symptoms may not appear until weeks after you return home.
The delayed onset of symptoms is one of the reasons malaria catches travellers off guard. You may feel perfectly healthy during your entire trip and only develop a fever after returning to Spain — or to your home country. By that point, many people and their doctors do not think of malaria as the cause, which delays diagnosis and treatment. Prophylactic tablets dramatically reduce this risk. Even in the uncommon event that a breakthrough infection occurs despite prophylaxis, the parasite load is lower and the illness is milder, giving you and your medical team more time to diagnose and treat it.[3]
Can You Buy Antimalarials at a Spanish Pharmacy?
All three antimalarial medications — atovaquone/proguanil, doxycycline, and mefloquine — are classified as prescription-only in Spain. A Spanish farmacia will stock them (or can order them quickly), but the pharmacist cannot dispense them without a valid receta médica. This is consistent across the country; there are no regional exceptions. What the pharmacy can sell you without a prescription are products that support your protection against mosquito bites. DEET-based insect repellent (look for products containing at least 30% DEET, or ask for repelente de insectos con DEET) is available over the counter and is strongly recommended by the WHO alongside antimalarial tablets.[1] You can also purchase permethrin-treated clothing sprays, mosquito nets if needed, and antihistamine creams for bite relief. These complement your malaria tablets but are not a substitute for them.