A Study to Investigate the Safety, Tolerability, and Pharmacokinetics (PK) of Oseltamivir and Its Carboxylate Metabolite, RO0640802 in Healthy Participants

Inclusion Criteria: * Participants with Body Mass Index (BMI) 18-34 kilograms per meter square (kg/m\^2), inclusive * Male participants who are willing to use barrier contraception for the duration of the study and for 3 months following the end of treatment * Female participants who are of non-child bearing potential * Female participants who are of child bearing potential utilizing two effective methods of contraception for the duration of the study and for 3 months following the end of treatment Exclusion Criteria: * Evidence of clinically significant disease or disorder (for example, renal, cardiac, bronchopulmonary) * Any other condition or disease which would place the participant at undue risk, or interfere with the assessment, or with the ability of the participant to complete the study * Clinically significant orthostatic hypotension present at screening or history of clinically significant hypotensive episodes or symptoms of fainting, dizziness, or lightheadedness. * Participants with abnormal electrocardiogram (ECG), bradycardia or mean QTc at screening * Positive result for Hepatitis B, Hepatitis C, human immunodeficiency virus (HIV) 1 or 2 at screening * Renal impairment * Transplant recipients * A known clinically relevant history of allergy or hypersensitivity * Any clinically relevant abnormal laboratory test results * A clinically relevant history of abuse of alcohol or other drugs of abuse * Any major illness within 30 days prior to the screening examination * Smoking of more than 10 cigarettes a day or an equivalent amount of tobacco in the form of cigars or pipe * Participation in a clinical study with an investigational drug within 3 months prior to Day 1 * Donation/loss of more than 500 milliliters (mL) of blood within 3 months prior to Day 1 * Positive pregnancy test at screening or Day -1 and lactating women