Atovaquone/Proguanil

What is Atovaquone/Proguanil?

Atovaquone/Proguanil is a type of medicine called an antimalarial. It contains two active ingredients, atovaquone and proguanil hydrochloride. It’s used to both treat and prevent malaria. You should start taking it two days before you start travelling to countries where there’s a high risk of malaria (mainly tropical countries).

Malaria is spread by infected mosquitoes that carry a parasite (called Plasmodium falciparum) that bite and pass it into the bloodstream. Atovaquone/Proguanil works to kill the parasite. On top of taking antimalarial medicine, you should be proactive about protecting yourself from getting bitten by mosquitoes.

• Use insect repellent on exposed skin
• Wear light-coloured clothing, especially after sunset, as this is when mosquitoes are most active
• Sleep under a mosquito net
• Use insecticide and close doors and windows (if they’re not screened already) ^[1]

You can still get bitten and infected by mosquitoes even after you’ve returned from your travels, as it can take a while for some types of infections to cause symptoms. It’s important to seek urgent medical attention if you develop symptoms. Symptoms include fever, headaches, confusion, fatigue, nausea, diarrhoea, loss of appetite, muscle pain, yellowing of the skin and whites of the eyes, sore throat, cough, and breathing difficulties. Typically, these symptoms appear between one and three weeks after you’ve been bitten, but they can also take months. ^[2]

How does Atovaquone/Proguanil work?

Atovaquone and Proguanil hydrochloride work together to kill the parasite that’s left by the infected mosquito. They do this by stopping the production of an organic compound called pyrimidines, which make up part of the DNA and is needed for making new genetic material in malarial parasites.

Separately, atovaquone works to stop the flow of electrons, which disrupts cellular processes, while proguanil stops the function of an enzyme called dihydrofolate reductase that helps make molecules for the parasite’s DNA. Proguanil can work by itself against malaria, but it also enhances the job of atovaquone, which is why they’re most effective combined as a treatment against malaria. ^[3]

Who is Atovaquone/Proguanil for?

According to the CDC (Centers for Disease Control and Prevention), this combination treatment can be good for last-minute travellers, because you only need to start taking it a couple of days before travelling. It’s also good for short trips because you only need to take it for seven days after your return, compared to other antimalarial medicines which can require a course of four weeks. Atovaquone/Proguanil is also available in a lower dose, so children can be protected as well. It’s available in any country that has a malaria risk. ^[4]

How to take Atovaquone/Proguanil

Follow the instructions given by your prescriber to ensure that your medication works effectively.

• Take Atovaquone/Proguanil with food or a milky drink. This increases the amount of medicine your body can absorb and makes the treatment more effective. ^[1]
• It’s best to take it at the same time every day

To prevent malaria:

• The recommended dose is one tablet (250/100 mg), once a day
• Start taking it one or two days before travelling
• Take it every day during your stay in the country
• Continue to take it for seven days after you’ve returned to a malaria-free country

To treat malaria:

• The recommended dose is four tablets, once a day for three days
• Make sure you take the full course so any parasites are fully killed

How long does Atovaquone/Proguanil take to work?

It has been found that proguanil is rapidly absorbed, with peak plasma concentrations reaching within two to four hours after 200 mg single doses and between one to six hours after 400 mg combined with 1000 mg atovaquone. Atovaquone has a reported half-life of two to three days in adults. ^[2] It’s recommended to start taking it two days before travelling for it to be fully effective and provide total protection against malaria.

What happens if I make a mistake using Atovaquone/Proguanil?

If you take more than you should, seek urgent medical attention immediately. If you forget to take a tablet, just take your next dose as soon as you remember. Don’t take a double dose to make up for the one you missed. Then continue your course of treatment as normal and take your next dose at the usual time the next day.