Antimalarial medication is used to prevent and treat malaria.
You should always consider taking antimalarial medicine when travelling to areas where there is a risk of malaria. Visit your GP or local travel clinic for malaria advice as soon as you know when and where you are going to be travelling.
It is very important that you take the correct dose and that you finish the course of antimalarial treatment. If you are unsure, check with your GP or pharmacist how long you should take your medication for.
It is usually recommended you take antimalarial tablets if you are visiting an area where there is a malaria risk because they can reduce your risk of malaria by about 90%.
The type of antimalarial tablets prescribed will be based on the following information you give:
- where you are going
- any relevant family medical history
- your medical history, including any allergies to medication that you have
- any medication that you are currently taking
- any problems that you have had with antimalarial medicines in the past
- your age
- whether you are pregnant (see below)
You may need to take a short trial course of antimalarial tablets before travelling. This is to check that you don't have an adverse reaction or side effects. If you do, alternative antimalarials can be prescribed before you leave.
Types of antimalarial medication
The main types of antimalarials used to prevent malaria are described below.
Atovaquone plus proguanil
- Dosage – the adult dose is one adult-strength tablet a day. Child dosage is also once a day, but the amount depends on the child’s weight. It should be started one or two days before your trip, taken every day that you are in a risk area and for seven days after you return.
- Recommendations – a lack of clear evidence means that this antimalarial should not be taken by pregnant or breastfeeding women. It is also not recommended for people with severe kidney problems.
- Possible side effects – stomach upset, headaches, skin rash and mouth ulcers.
- Other factors – it can be more expensive than other antimalarials so may be more suitable for short trips.
Doxycycline (also known as Vibramycin-D)
- Dosage – the dose is 100mg daily as a tablet or capsule. You should start the tablets two days before you travel, take them each day you are in a risk area and for four weeks after you return.
- Recommendations – not suitable for pregnant or breastfeeding women, children under the age of 12 (due to the risk of permanent tooth discolouration), people who are sensitive to tetracycline antibiotics or people with liver problems.
- Possible side effects – sunburn due to light sensitivity, stomach upset, heartburn and thrush. It should always be taken with food, preferably when standing or sitting. Doxycycline reduces the effectiveness of combined hormone contraceptives, such as the contraceptive pill or contraceptive patches.
- Other factors – if you take doxycycline for acne, it will also provide protection against malaria as long as you are taking an adequate dose (ask your GP). Doxycycline is relatively cheap.
Mefloquine (also known as Lariam)
- Dosage – the adult dose is one tablet weekly. Child dosage is also once a week but the amount will depend on the child’s weight. It should be started three weeks before you travel, taken all the time you are in a risk area and for four weeks after you get back.
- Recommendations – it is not recommended if you have epilepsy, seizures, depression or other mental health problems, or if a close relative has any of these conditions. It is not usually recommended for people with severe heart or liver problems.
- Possible side effects – dizziness, headache, sleep disturbances (insomnia and vivid dreams) and psychiatric reactions (anxiety, depression, panic attacks and hallucinations). It is very important to tell your doctor about any previous mental health problems, including mild depression. Do not take this medication if you have a seizure disorder.
- Other factors – if you have not taken mefloquine before, it is recommended that you do a three-week trial before you travel to see whether you develop any side effects.
Chloroquine and proguanil
A combination of antimalarial medications called chloroquine and proguanil is also available, although these medications are rarely recommended nowadays because they are largely ineffective against the most common (particularly in Africa) and dangerous type of malaria parasite called Plasmodium falciparum.
However, chloroquine and proguanil may occasionally be recommended for certain destinations where the Plasmodium falciparum parasite is less common than other types, such as India and Sri Lanka.
If malaria is diagnosed and treated promptly, a full recovery can be expected. Treatment should be started as soon as a blood test confirms malaria.
Many of the same antimalarial medicines used to prevent malaria can also be used to treat malaria. However, if you have taken an antimalarial to prevent malaria, you should not take the same one to treat malaria if you still become infected. Therefore, it is important to tell the doctor treating you the name of the tablets that you took to help prevent infection.
The type of antimalarial medicine and how long you need to take it will depend on:
- the type of malaria you have
- where you caught malaria
- the severity of your symptoms
- whether you took preventative antimalarial tablets
- your age
- whether you are pregnant
Your doctor may recommend using a combination of different antimalarials to overcome strains of malaria that have become resistant to single types of medication.
Antimalarial medication is usually given as tablets or capsules. If someone is very ill, it will be given through a drip into a vein in the arm (intravenously) in hospital.
Treatment for malaria can leave you feeling very tired and weak for several weeks.
Emergency standby treatment
Before you travel, you may be prescribed an emergency course of antimalarial medicine if there is a risk of you becoming infected with malaria while travelling in a remote area where there is little or no access to medical care.
Examples of medications that may be prescribed to treat malaria in an emergency include atovaquone with proguanil, artemether with lumefantrine, quinine plus doxycycline and quinine plus clindamycin.
Your GP may decide to seek advice from a travel health specialist before prescribing emergency standby treatment.
Read more about emergency treatment for malaria.
Antimalarials in pregnancy
If you are pregnant, it is advisable to avoid travelling to areas where there is a risk of malaria.
Pregnant women have an increased risk of developing severe malaria and both the baby and mother could experience serious complications.
If you are pregnant and unable to postpone or cancel your trip to an area where there is a malaria risk, it is very important that you take the right antimalarial medicine.
Some of the antimalarials used to prevent and treat malaria are unsuitable for pregnant women because they can cause side effects for the mother and her baby.
The list below outlines which medications are safe or unsafe to use while pregnant:
- Mefloquine isn't usually prescribed during the first trimester of pregnancy, or if pregnancy is a possibility during the first three months after preventative antimalarial medication is stopped. This is a precaution even though there is no evidence to suggest that mefloquine is harmful to an unborn baby.
- Doxycycline is never recommended for pregnant or breastfeeding women because it could harm the baby.
- Atovaquone plus proguanil is generally not recommended during pregnancy or breastfeeding because research into their effects is limited. However, if the risk of malaria is high, they may be recommended if there is no suitable alternative.
Chloroquine combined with proguanil is suitable during pregnancy, but it is rarely used because it is not very effective against the most common and dangerous type of malaria parasite.