What Are the Most Common Antimalarial Side Effects?

Common antimalarial side effects can include nausea, rashes, and intestinal upset. The specifics can depend on the type of medication a patient takes, the dosage, and the length of treatment. People use these medications prophylactically to prevent malaria infection while visiting regions with a high incidence of malaria-causing parasites, as well as to treat specific outbreaks of disease. Certain other conditions, including lupus, may be treated with antimalarials because they appear to provide some benefits.

Quinine is among the oldest and most well-known antimalarials. Patients may also take medications like doxycycline, chloroquine, or mefloquine, among others. The most appropriate option can depend on why the patient needs the medication, and they may be provided in combination therapies to combat resistance. Each medication comes with its own side effects and these can be worse in the case of a drug interaction with another medication.

Nausea, vomiting, and diarrhea can occur on some antimalarial medications. Other patients may report antimalarial side effects like headaches and blurred vision. Some medications have been known to cause tinnitus, a ringing sound in the ears. Rashes can also be an issue, along with ulcerations in the mouth. Some of these antimalarial side effects can become worse while traveling if the patient consumes contaminated food or gets stressed out, in which case physical or emotional stress may be confused with a medication reaction.

Psychiatric reactions are also documented antimalarial side effects. Some medications are associated with mood changes, including psychosis, hallucinations, and nightmares. Patients who notice changes in their mood or who feel unstable can contact a medical provider to get advice on how to proceed. It may be possible to change medications or doses to provide protection without the unwanted drug reaction. Counseling is also available to help people address specific issues that may arise.

Some antimalarial side effects can be so intense that patients want to discontinue the medication. This is not generally advised, because it can put them at risk of infection. If side effects are severe, patients should bring this up to determine if there is another drug available that can provide the same level of protection. Patients should also ask about what they should do if they vomit shortly after taking a dose, as the medication may not have a chance to spread into the bloodstream, in which case they may need a follow-up dose to ensure they get the benefit of the drug.