The goal of this study is to identify at least one safe and well tolerated dose of MK1809 that has similar pharmacokinetic qualities as 100 mg losartan.

Inclusion Criteria:

Part 1:

• Nonsmoker for at least 6 months
• Body Mass Index (BMI) less than or equal to 29 kg/m2
• In overall good health

Part 2:

• Body Mass Index (BMI) greater than 18kg/m2 and less than or equal to 35kg/m2
• In overall good health (patients with hypertension and/or hyperlipidemia are accepted)

Exclusion Criteria:

Part 1:

• History of any cardiovascular disease or any clinically significant family history of cardiac arrhythmias or conduction abnormalities at an age less than 60 years
• History of any major endocrine, vascular, hematologic, gastrointestinal, hepatic, renal or genitourinary disease/disorder
• History of cancer
• Clinically significant history of a neurological disorder (includes epilepsy,stroke, transient ischemic attack, classic migraines)
• Active or history of a psychiatric disorder (includes depression, bipolar disorder, schizophrenia, anxiety)
• History of asthma, severe wheezing, COPD, or other pulmonary disease
• Individual or family history of bleeding or hemorrhagic diathesis, or bleeding difficulties
• Major surgery, donated blood or participated in another investigational drug(s) trial within 30 days
• Illicit drug use (including recreational); or history of drug or alcohol abuse (within 2 years)
• Nitrate therapy within 4 weeks
• History of significant drug allergy or history of food allergies

Part 2

• History of any clinically significant cardiac or cardiovascular disease (other than hypertension)
• History of any major endocrine, vascular, hematologic, gastrointestinal, hepatic, renal or genitourinary disease/disorder
• History of cancer
• History of a neurological disorder (includes epilepsy,stroke, transient ischemic attack, classic migraines)
• Active or history of a psychiatric disorder (includes depression, bipolar disorder, schizophrenia, anxiety)
• History of asthma, severe wheezing, COPD, or other pulmonary disease
• Individual or family history of bleeding or hemorrhagic diathesis, or bleeding difficulties
• Illicit drug use (including recreational); or history of drug or alcohol abuse (within 2 years)
• Surgery, significant blood loss, donated blood, or participated in another investigational drug(s) trial within 30 days
• Nitrate therapy within 4 weeks
• History of significant drug allergy