Atovaquone and proguanil are combination medications used to prevent and treat malaria. Atovaquone works by inhibiting the mitochondrial electron transport chain in the parasite, which disrupts energy production and prevents the parasite from surviving and multiplying. Proguanil is a prodrug that is converted into cycloguanil, which inhibits the parasite’s dihydrofolate reductase enzyme, interfering with DNA synthesis and parasite replication. When used together, these drugs have a synergistic effect, making it more difficult for malaria parasites to develop resistance.
For prophylaxis, atovaquone-proguanil is taken daily, starting one or two days before entering an endemic area, continuing during the stay, and for seven days after leaving. For treatment of uncomplicated malaria, the medication is typically administered once daily for three days. The combination is generally well tolerated, with common side effects including nausea, abdominal pain, headache, and rash. Because of its effectiveness and low resistance rates, it is a popular choice for travelers and patients with uncomplicated malaria.
It is important to consult a healthcare provider before use, especially for pregnant women or individuals with kidney or liver problems, and to be aware of potential drug interactions with other medications.
Take 1 tablet at the same time each day with food or a milky drink, where possible.
Start taking the tablets daily 2 days before visiting a malaria risk area. Keep taking 1 tablet every day while in the area, and for 7 days after you leave.
Common Side Effects
- **Nausea:** Feelings of queasiness are frequent and may occur shortly after taking the medication.
- **Abdominal Pain:** Discomfort or cramping in the stomach area can happen, usually mild and transient.
- **Diarrhea:** Increased stool frequency or loose stools are common but typically mild.
- **Headache:** Many patients report headaches during treatment.
- **Dizziness:** Some individuals may feel lightheaded or dizzy, especially when standing up quickly.
- **Rash:** Mild skin rashes can occur as an allergic reaction or sensitivity to the medication.
Less Common or Less Severe Side Effects
- **Vomiting:** Some people may experience nausea leading to vomiting, which can affect medication adherence.
- **Loss of Appetite:** A decreased desire to eat can occur in some individuals.
- **Sleep Disturbances:** Insomnia or unusual dreams may be reported.
- **Muscle or Joint Pain:** Aches in muscles or joints may be experienced during therapy.
Rare or Serious Side Effects
- **Allergic Reactions:** These can include swelling of the lips, tongue, or face, difficulty breathing, hives, or severe skin rash. Immediate medical attention is required if these occur.
- **Liver Function Abnormalities:** Elevated liver enzymes or signs of liver inflammation, such as jaundice (yellowing of the skin or eyes), dark urine, or abdominal pain, may develop.
- **Hemolytic Anemia:** Although rare, especially in individuals with G6PD deficiency, hemolysis can occur leading to anemia, fatigue, jaundice, or dark-colored urine.
- **Neuropsychiatric Effects:** Rarely, some individuals may experience anxiety, depression, or other mood changes during treatment.
Patients with known hypersensitivity to either medication should avoid use. The drugs are not recommended during pregnancy unless clearly needed, as safety data is limited, and they should be used during pregnancy only if the potential benefits outweigh risks.
Proguanil can cause hemolytic anemia, especially in individuals with G6PD deficiency, so screening for G6PD deficiency is recommended before starting treatment. People with severe renal impairment may require dosage adjustments or closer monitoring, as kidney function affects drug clearance.
Liver function should be monitored in patients with pre-existing liver disease, as rare cases of hepatotoxicity have been reported. The medications should be used with caution in patients with liver or kidney problems.
Patients should be advised to complete the full course of therapy and to report any severe or unusual side effects promptly. Avoid combining atovaquone-proguanil with drugs that may interact adversely, such as certain anticonvulsants or drugs affecting CYP450 enzymes, to prevent reduced effectiveness or increased adverse effects.
Lastly, it’s important to note that atovaquone-proguanil is not recommended for use in children weighing less than 11 kg, and safety in such populations has not been established. Always consult a healthcare provider for personalized medical advice before use.
