Although some doctors assume otherwise, a cocktail of drugs to slow the development of AIDS works as well in infected individuals who are injectable drug users as in other people with the HIV virus, the National Institutes of Health announced Wednesday.

The medical research agency noted that the cocktail has been “extremely effective” at slowing the progression of HIV infection to AIDS and at extending the lives and improving the quality of life of those with the virus.

The medical research agency said a study of some 3,116 patients on “highly active antiretroviral therapy” (HAART) found that the mortality rate after seven years of people in the study who were injectable drug users was equivalent to that for study participants who did not inject drugs.

“To compare the number of deaths between the two groups, the researchers took into account that accidental deaths are more common for injection drug users and excluded those deaths from their analyses,” NIH noted in a press release announcing the findings.

When accidental deaths were excluded, the mortality rate among injection drug users was 22 percent compared with about 19 percent among those that did not inject drugs.

“An estimated one million persons in the United States are living with HIV/AIDS, with approximately one-fourth of these cases attributable to injection drug use,” said Nora D. Volkow, director of NIH’s National Institute on Drug Abuse. “This paper provides important evidence for the value of routinely providing HAART therapy to HIV-infected injection drug users who need treatment — benefiting both the patients and the public at large.”

“Hopefully, the findings from this study help address the commonly held assumption that HIV-positive injection drug users do not derive the full benefits of HIV treatment,” said Evan Wood, the lead author of the study, which was published Wednesday in the Journal of the American Medical Association. “We have an ethical and human rights imperative to deliver care to this population, not only to reduce illness and death, but also to possibly reduce the rate of new infections in the community,” Wood said.

The drug regimen consists of a cocktail of at least three medications that can decrease the level of HIV in the blood. HIV is the virus that causes AIDS.