NAC Well-Tolerated But Shows No Benefit to Patients with HIV in Preliminary Study

received either intravenous doses of NAC three times a week for six weeks, followed by six
weeks of the drug in the form of effervescing tablets dissolved in water, or the oral form of
the drug first, followed by intravenous doses.
Study physicians evaluate all patients once a week at the clinic. Thus far, they have
found no benefit of NAC to patients, as determined by looking at the markers of the
progression of HIV disease, such as the amount of virus in the blood or the numbers of the
patients' CD4+ cells.
CD4+ T cells are white blood cells crucial to the functioning of the immune system
and are attacked by HIV. Patients in the study all had fewer than 500 CD4+ T cells per
cubic millimeter (mm') of blood upon their enrollment. Healthy people without HIV
infection usually have between 800 and 1500 CD4+ T cells/mm'.
Dr. Walker and his colleagues have noted no serious adverse effects related to oral
doses of the drug. Side effects after intravenous doses of NAC, such as flushing and allergictype reactions, increased in severity and frequency with higher doses of the drug.
NAC, manufactured by the Zambon, USA, is commonly prescribed in the United
States for acetaminophen (Tylenol) poisoning.
In addition to Dr. Walker, the study investigators include, from the NIAID Laboratory
of Immunoregulation, Laboratory Chief and NIAID Director Anthony S. Fauci, M.D.,
H. Clifford Lane, M.D., Christine M. Boenning, R.N., and Richard T. Davey, M.D. Other
collaborators include, from the NIH Clinical Center, Michael A. Polis M.D., M.P.H., Joseph
A. Kovacs, M.D., Judith Falloon, M.D., and Henry Masur, M.D.; from Stanford University,
Howard Sussman, M.D.; and from Zambon Corp., East Rutherford, N.J., Rafael CorreaCoronas, M.D., and Lloyd Gabel, Ph.D.
NAID and the Clinical Center are components of the National Institutes of Health
in Bethesda, Maryland. MIAID supports research on allergy, immunology and infectious
diseases, including an extensive AIDS clinical research program at the Clinical Center, a
500-bed hospital on the MIH campus.