The purpose of this study is to find out whether taking certain anti-HIV medicines with certain antimalarial medicines affects the amount of the medicines in the blood.

The study medicines that will be used are artemether/lumefantrine (antimalarial medication) and lopinavir/ritonavir or efavirenz (anti-HIV medications). Artemether/lumefantrine is not approved by the United States Food and Drug Administration (FDA) but is recommended as standard of care medical treatment for malaria in Africa and Asia. Lopinavir/ritonavir and efavirenz are approved by the FDA. Artemether/lumefantrine and lopinavir/ritonavir or efavirenz may need to be used together to treat children in Africa and Asia. We seek to learn about whether or not the use of these medicines together results in a change in blood levels of any of these medicines. The information obtained from this study will help doctors to provide a better treatment to children and adults with malaria and HIV.

The study involves 5 non-consecutive overnight stays and 14 additional outpatient visits at the San Francisco General Hospital Research Center.

Inclusion Criteria:

• Absence of HIV infection prior to study entry
• Within 20% (+/-) of ideal body weight and must weigh at least 50kg
• Healthy subjects without evidence of acute or chronic illnesses, including diabetes, high blood pressure, coronary artery disease, psychiatric illnesses, liver or kidney impairment

Exclusion Criteria:

• Use of illicit drugs or alcohol that could interfere with the completion of the study.
• Use of any over- the- counter or prescribed drugs unless approved by the principal investigator or study physician.
• Pregnant or breast- feeding.
• History of acute or chronic illnesses, such as diabetes, high blood pressure, coronary artery disease, psychiatric illnesses, liver or kidney impairment.
• Evidence of acute illness.
• Family history of congenital prolongation of QTc interval or with any conditions known to prolong QTc interval, such as cardiac arrhythmias, bradycardia or severe heart disease
• History of electrolyte abnormalities.