- Subjects with epilepsy; pernicious anemia; hematological illnesses; known HIV infection; any clinically unstable cardiovascular (including a myocardial infarction [heart attack] in the 3 months prior to screening), hematological, autoimmune, endocrine, renal, hepatic (including chronic hepatitis B, hepatitis B within the 3 months prior to screening) respiratory, or gastrointestinal disease; symptomatic peripheral vascular disease including intermittent claudication; uncontrolled diabetes mellitus; untreated hypothyroidism.