CompletedPhase 1

Nitrite Infusion in Healthy Volunteers

United States12 participantsStarted 2005-02-04

Plain-language summary

This study will determine the dose of sodium nitrite that can safely be used to prevent constriction, or tightening, of the arteries. Narrowed arteries in the brain can cause stroke. Animal studies show that nitrite injections improve blood flow and that injections over long periods of time prevent damage to the arteries in the brain; however, there is no information on the effects of prolonged nitrite infusion in humans. This study will establish the safe dose and side effects of nitrite infusion in humans. Healthy normal volunteers between 21 and 60 years of age may be eligible for this study. Candidates are screened for high or low blood pressure, aspirin use, pregnancy, and blood levels of nitrite and methemoglobin (a substance that temporarily and slightly lowers the oxygen carried in the red blood cells). Pregnant women are excluded from the study. Participants are admitted to the Clinical Center for 16 1/4 days, the first 2 days in the hospital's intensive care unit (ICU). Upon admission they provide a medical history, have physical and cardiovascular examinations, and blood tests. For the infusion procedure, a catheter (thin plastic tube) is inserted into an artery in the wrist or the crease of the elbow to measure blood pressure, and catheters are placed in a vein in each arm for administering the nitrite and withdrawing blood samples. In the morning of day 1, after initial blood pressure and heart rate measurements are taken and a blood sample is drawn, a saline (salt water) infusion is started. Blood pressure and heart rate are monitored every 30 minutes for 6 hours, then every hour for 6 hours, then every 2 hours for 12 hours. Blood samples are collected every 4 hours for 24 hours. On day 2, the sodium nitrite infusion begins. Blood pressure and methemoglobin are monitored every 10 minutes for the first 2 hours. If blood pressure remains stable, the frequency of measurements is decreased to every 30 minutes for 4 hours, then every 1 hour for the next 6 hours, and then every 4 hours for 12 hours. If the pressure continues to remain stable, monitoring continues every 8 hours for the rest of the study. Blood is drawn periodically from the catheter to determine the amount of nitrite and methemoglobin in the body, with decreasing frequency from several times during the first hour of the infusion to every 24 hours. After the first 24 to 48 hours of the nitrite infusion, participants are transferred from the ICU to a general nursing unit fo...

Who can participate

Age range

21 Years – 60 Years

Sex

ALL

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AI-rewrites the medical criteria so a patient or caregiver can understand them. Always confirm with the trial site.

* INCLUSION CRITERIA: Subjects must be 21-60 years of age. Subjects must be in good health. Subjects must provide informed, written consent for participation in this study. Female subjects of childbearing age must have a negative pregnancy test and agree to participate in assessment of menstrual cycle duration before, during, and after infusion. Subjects must be willing to temporarily stop any medications (except oral contraception), vitamin supplements, herbal medicines. Subjects will have hemoglobin levels above 11.1 g/dL. EXCLUSION CRITERIA: Subjects with a history or evidence of present or past hypertension (blood pressure greater than 140/90 mmHg), hypercholesterolemia (LDL cholesterol greater than 130 mg/dL), or diabetes mellitus (fasting blood glucose greater than 126 mg/dL). Subjects who have a history of smoking within two years. Subjects who have a history of cardiovascular disease, peripheral vascular disease, coagulopathy, or any other disease predisposing to vasculitis or Raynaud's phenomenon. Subjects with red blood cell G6PD deficiency (levels below the lower limits of normal). Subjects with a history of reaction to a medication or other substance characterized by dyspnea and cyanosis. Subjects with a baseline methemoglobin level greater than 1%. Pregnant women, since nitrite may cross the placenta; nitrite effect on fetus is unknown and mother's methemoglobinemia may be dangerous to the fetus. Breast-feeding females, since nitrite crosses into b…

Questions worth asking your doctor

Bring these to your next appointment. They're a starting point for a shared conversation — not a sign you qualify or a recommendation to enrol.

1Based on my diagnosis and history, is this trial worth exploring for me — or is there a standard treatment we should try first?
2What does this trial's phase tell us about how much is already known about its safety and benefit?
3What would taking part actually involve for me — visits, tests, time, and travel?
4What are the known and possible risks or side effects I should weigh, and how would they be monitored?
5If this trial isn't the right fit, what other options or trials would you suggest I look into?

Generated to help you prepare — always confirm anything about your own eligibility and care with the study team and your doctor.

Questions for the trial coordinator

The trial coordinator is the person who runs the study day to day. These cover the practical side — logistics, costs, and what taking part would actually mean for your life. The study team confirms whether you meet the criteria; these are questions to ask, not a sign you qualify.

1What does taking part actually involve week to week — how many visits, where, and how long does each one take?
2What costs are covered by the study, and what might I have to pay for myself, including travel, parking, or time off work?
3What happens during screening, and what happens if the study team confirms I don't meet the criteria after those tests?
4Who pays for the scans, blood work, and other tests the trial requires — the study, my insurance, or me?
5How will being in the trial affect my regular care, and will my own doctor stay informed and involved?
6Can I leave the trial at any point if I change my mind, and what would happen to my care if I do?

A starting point for the conversation — always confirm anything about your own eligibility, costs, and care with the study team and your doctor.

Trial details

NCT IDNCT00103025

SponsorNational Institute of Neurological Disorders and Stroke (NINDS)

Sponsor typeNIH

Study typeINTERVENTIONAL

Primary completion2011-05-10

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