1. females who are pregnant, breastfeeding or planning to become pregnant during the course of the study. 2. patients unresponsive or unable to take anything by mouth (npo). 3. individuals who are cognitively impaired and/or who are unable to give informed consent. 4. blood pressure below 110 mmhg systolic and 60 mmhg diastolic on entry into study. 5. history of syncope or other symptoms of orthostatic hypotension. 6. history of methemoglobinemia. 7. severe case of g6pd deficiency

1. females who are pregnant, breastfeeding or planning to become pregnant during the course of the study. 2. patients unresponsive or unable to take anything by mouth (npo). 3. individuals who are cognitively impaired and/or who are unable to give informed consent. 4. blood pressure below 110 mmhg systolic and 60 mmhg diastolic on entry into study. 5. history of syncope or other symptoms of orthostatic hypotension. 6. history of methemoglobinemia. 7. severe case of g6pd deficiency

females who are pregnant, breastfeeding or planning to become pregnant during the course of the study. patients unresponsive or unable to take anything by mouth (npo). individuals who are cognitively impaired and/or who are unable to give informed consent. blood pressure below 110 mmhg systolic and 60 mmhg diastolic on entry into study. history of syncope or other symptoms of orthostatic hypotension. history of methemoglobinemia. severe case of g6pd deficiency

females who are pregnant, breastfeeding or planning to become pregnant during the course of the study. patients unresponsive or unable to take anything by mouth (npo). individuals who are cognitively impaired and/or who are unable to give informed consent. blood pressure below 110 mmhg systolic and 60 mmhg diastolic on entry into study. history of syncope or other symptoms of orthostatic hypotension. history of methemoglobinemia. severe case of g6pd deficiency

1. females who are pregnant, breastfeeding or planning to become pregnant during the course of the study. 2. patients unresponsive or unable to take anything by mouth (npo). 3. individuals who are cognitively impaired and/or who are unable to give informed consent. 4. blood pressure below 110 mmhg systolic and 60 mmhg diastolic on entry into study. 5. history of syncope or other symptoms of orthostatic hypotension. 6. history of methemoglobinemia. 7. severe case of g6pd deficiency

1. females who are pregnant, breastfeeding or planning to become pregnant during the course of the study. 2. patients unresponsive or unable to take anything by mouth (npo). 3. individuals who are cognitively impaired and/or who are unable to give informed consent. 4. blood pressure below 110 mmhg systolic and 60 mmhg diastolic on entry into study. 5. history of syncope or other symptoms of orthostatic hypotension. 6. history of methemoglobinemia. 7. severe case of g6pd deficiency

1. females who are pregnant, breastfeeding or planning to become pregnant during the course of the study. 2. patients unresponsive or unable to take anything by mouth (npo). 3. individuals who are cognitively impaired and/or who are unable to give informed consent. 4. blood pressure below 110 mmhg systolic and 60 mmhg diastolic on entry into study. 5. history of syncope or other symptoms of orthostatic hypotension. 6. history of methemoglobinemia.

1. females who are pregnant, breastfeeding or planning to become pregnant during the course of the study. 2. patients unresponsive or unable to take anything by mouth (npo). 3. individuals who are cognitively impaired and/or who are unable to give informed consent. 4. blood pressure below 110 mmhg systolic and 60 mmhg diastolic on entry into study. 5. history of syncope or other symptoms of orthostatic hypotension. 6. history of methemoglobinemia.