See also How to Use section.

Drug interactions may change how your medications work or increase your risk for serious side effects. This document does not contain all possible drug interactions. Keep a list of all the products you use (including prescription/nonprescription drugs and herbal products) and share it with your doctor and pharmacist. Do not start, stop, or change the dosage of any medicines without your doctor's approval.

Be sure to tell your doctor about all medications you take for malaria within the 4 weeks before, during, and after treatment with artemether/lumefantrine. Some antimalarial drugs (such as halofantrine) should not be used within one month of treatment with artemether/lumefantrine. In some cases a serious (possibly fatal) drug interaction may occur.

Many drugs besides artemether/lumefantrine may affect the heart rhythm (QT prolongation), including other antimalarial drugs (such as quinine, quinidine), antiarrhythmic drugs (such as amiodarone, sotalol, procainamide, disopyramide), antipsychotics (such as pimozide, ziprasidone), macrolide antibiotics (such as erythromycin), quinolone antibiotics (such as ciprofloxacin, moxifloxacin), among others.

Other medications can affect the removal of artemether/lumefantrine from your body, which may affect how this product works. Examples include azole antifungals (such as ketoconazole, itraconazole), mefloquine, HIV NNRTIs (such as efavirenz), HIV protease inhibitors (such as nelfinavir), rifamycins (such as rifabutin, rifampin), ritonavir, St. John's wort, some anti-seizure drugs (such as carbamazepine, phenobarbital, phenytoin), among others.

This medication can speed up or slow down the removal of other medications from your body, which may affect how they work. Examples of affected drugs include clomipramine, flecainide, certain beta blockers such as metoprolol, certain tricyclic antidepressants (such as amitriptyline and imipramine), among others.

This medication may decrease the effectiveness of hormonal birth control such as pills, patch, or ring. This could cause pregnancy. Discuss with your doctor or pharmacist if you should use reliable backup birth control methods while using this medication. Also tell your doctor if you have any new spotting or breakthrough bleeding, because these may be signs that your birth control is not working well.