Evaluate the Pharmacokinetics and Safety of MK-4448 in Participants With Nonvalvular Atrial Fibrillation or Atrial Flutter

Inclusion Criteria: * In the opinion of the investigator, participant requires long term anticoagulation for stroke prevention in atrial flutter (AF). * Men and women ≥18 years of age. * Participant has current non-valvular atrial fibrillation (NVAF) or AF or electrocardiogram (ECG) or Holter documentation within past 12 months. * Participant has an international normalized ratio (INR) ≤ 2.2 at allocation (Visit 2). * A participant who is of reproductive potential agrees to remain abstinent or use (or have their partner use) 2 acceptable methods of birth control for the duration of the study. Acceptable methods of birth control are: intrauterine device (IUD), diaphragm with spermicide, condom, vasectomy, and hormonal contraception. * Participant understands the study procedures and risks involved with the study, and voluntarily agree to participate by giving written informed consent. Exclusion Criteria: General * Participant is currently participating in another drug study or has received an investigational drug within 30 days prior to enrollment. * Participant is a woman who is pregnant, lactating or of child-bearing potential who refuses to use a medically acceptable form of contraception throughout the study. * Participant has a body weight less than 40 kg (88 lbs) or greater than 200 kg (440 lbs). * Participant routinely consumes more than 2 alcoholic drinks per day (average \>14 alcoholic drinks per week) or greater than 5 drinks within 2 hours on occasion. Prohibit…