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PubMed This is a summary of 8 peer-reviewed journal articles Updated
Infectious Disease

What Are the Side Effects of ACT Malaria Medicines?

At a Glance

Most ACT malaria medicine side effects—such as nausea, vomiting, headache, dizziness, fatigue, and poor appetite—are mild, but vomiting can prevent enough medicine from being absorbed. Follow product instructions and seek urgent care for severe allergy, heart symptoms, or signs of severe malaria.

In this answer

3 sections

01

The Challenge of Vomiting

02

Managing Common Side Effects

03

When to Seek Medical Help

Artemisinin-based Combination Therapies (ACTs) are highly effective at treating malaria, but like all medications, they can cause side effects. The most commonly reported side effects include nausea, vomiting, headache, dizziness, abdominal discomfort, weakness (fatigue), and loss of appetite [1][2].

Most of these side effects are mild and self-limited [1][3]. However, because malaria itself can cause symptoms like headache, weakness, nausea, and poor appetite, you should not assume that severe or worsening symptoms are “just side effects.”

The Challenge of Vomiting

Vomiting is a common issue with ACTs, and it can be dangerous because your body may not absorb enough of the medicine to cure the malaria [4][5].

  • Do not automatically repeat a dose: The rules for what to do if you vomit depend entirely on the specific ACT you are taking. Some ACT instructions require you to take another dose if you vomit within a certain timeframe, but this timeframe varies by product. Taking an extra dose when it is not needed can cause an overdose.
  • Check your instructions: Check the medication leaflet or contact your clinic or pharmacist immediately to find out what to do for your specific medication if you vomit.
  • Complete the course: Never stop taking your medication early, even if you feel unwell or start to feel better [5]. Stop only if a healthcare professional tells you to.

Managing Common Side Effects

Managing your side effects can make completing your treatment much more comfortable. Here are some practical steps:

  • Food instructions are specific to your medication: Some ACTs (such as artemether-lumefantrine) should be taken with food or a milky drink to help the body absorb the medicine [6]. Others (such as dihydroartemisinin-piperaquine) are meant to be taken on an empty stomach. Follow the exact instructions provided by your doctor or pharmacist.
  • Stay Hydrated: Drink fluids in small, frequent sips to stay hydrated without upsetting your stomach.
  • Rest: Give your body time to rest and recover.
  • Check before taking other medicines: Do not take anti-vomiting medication, antacids, or other over-the-counter products without asking a pharmacist, as they can interfere with your ACT.

When to Seek Medical Help

Seek EMERGENCY care immediately if you experience:

  • Inability to keep medication or fluids down: If persistent vomiting prevents you from keeping fluids in your body or replacing a vomited dose, your treatment will need to be urgently adjusted.
  • Signs of a severe allergic reaction: This includes swelling of the face or throat, difficulty breathing, or a widespread rash [7].
  • Heart rhythm issues: Fainting, severe dizziness, or a racing, pounding, or fluttering heartbeat (palpitations). Certain ACTs can affect the electrical rhythm of the heart, so it is important to disclose any history of heart issues to your doctor [8].
  • Signs of severe malaria: Confusion, inability to wake up, seizures, extreme weakness, or jaundice (yellowing of the eyes or skin).

Contact your doctor promptly if:

  • Your symptoms do not improve within a couple of days, or if your fever returns.
  • You vomit a dose and are unsure what to do.

Common questions in this guide

What side effects are common with ACT malaria medicines?
Common effects include nausea, vomiting, headache, dizziness, abdominal discomfort, fatigue, and reduced appetite. They are often mild and settle on their own, but malaria can cause some of the same symptoms, so worsening or severe symptoms need medical attention.
What should I do if I vomit after taking an ACT dose?
Do not automatically take another dose because the correct timing for repeating a dose depends on the exact ACT product, and an unnecessary extra dose can cause harm. Check the medication leaflet or contact a pharmacist or clinic promptly, especially if you cannot keep fluids or medicine down.
Do ACT malaria medicines need to be taken with food?
It depends on the medicine. Artemether-lumefantrine is taken with food or a milky drink, while dihydroartemisinin-piperaquine is taken on an empty stomach; follow your prescription or medication leaflet.
When should ACT side effects be treated as an emergency?
Get emergency care for trouble breathing, facial or throat swelling, a widespread rash, fainting, severe dizziness, a racing or fluttering heartbeat, inability to keep medicine or fluids down, confusion, seizures, extreme weakness, or jaundice. These symptoms can signal a severe allergic reaction, heart rhythm problem, or severe malaria.
Should I stop my ACT medicine if I start feeling better or unwell?
Do not stop the course early unless a healthcare professional tells you to. Contact a clinician promptly if symptoms worsen, do not improve within a couple of days, or your fever returns.

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References

References (8)
  1. 1

    Efficacy and safety of artemisinin-based combination therapies for the treatment of uncomplicated malaria in pediatrics: a systematic review and meta-analysis.

    Shibeshi W, Alemkere G, Mulu A, Engidawork E

    BMC infectious diseases 2021; (21(1)):326 doi:10.1186/s12879-021-06018-6.

    PMID: 33827422
  2. 2

    Efficacy and Safety of Artemisinin-Piperaquine for the Treatment of Uncomplicated Malaria: A Systematic Review.

    Wang Q, Zou Y, Pan Z, et al.

    Frontiers in pharmacology 2020; (11()):562363 doi:10.3389/fphar.2020.562363.

    PMID: 33013398
  3. 3

    Adverse Drug Reactions and Changes in Haematological and Clinical Chemistry to Two ACTs among Nigerian Children with Acute Uncomplicated Malaria.

    Anjorin OE, Anjorin IA, Falade CO

    West African journal of medicine 2023; (40(12)):1332-1340.

    PMID: 38261578
  4. 4

    Triple therapy with artemether-lumefantrine plus amodiaquine versus artemether-lumefantrine alone for artemisinin-resistant, uncomplicated falciparum malaria: an open-label, randomised, multicentre trial.

    Peto TJ, Tripura R, Callery JJ, et al.

    The Lancet. Infectious diseases 2022; (22(6)):867-878 doi:10.1016/S1473-3099(21)00692-7.

    PMID: 35276064
  5. 5

    Adherence to Artemisinin Combination Therapy for the treatment of uncomplicated malaria in the Democratic Republic of the Congo.

    Siddiqui MR, Willis A, Bil K, et al.

    F1000Research 2015; (4()):51 doi:10.12688/f1000research.6122.2.

    PMID: 25949803
  6. 6

    Adherence to Artemisinin-Based Combination Therapy for the Treatment of Uncomplicated Malaria: A Systematic Review and Meta-Analysis.

    Yakasai AM, Hamza M, Dalhat MM, et al.

    Journal of tropical medicine 2015; (2015()):189232 doi:10.1155/2015/189232.

    PMID: 26161095
  7. 7

    Drug-induced hypersensitivity to artemisinin-based therapies for malaria.

    Nordmann T, Borrmann S, Ramharter M

    Trends in parasitology 2022; (38(2)):136-146 doi:10.1016/j.pt.2021.08.011.

    PMID: 34561157
  8. 8

    [Treatment of imported Plasmodium falciparum malaria: role of the combination of dihydroartemisinin and piperaquine].

    Le Garlantezec P, Richard C, Broto H, Rapp C

    Medecine et sante tropicales 2015; (25(2)):136-40 doi:10.1684/mst.2014.0369.

    PMID: 25296031

This page explains possible side effects of ACT malaria medicines for informational purposes only and does not replace medical advice. Ask your doctor or pharmacist how to manage symptoms and what to do if you vomit a dose.