TUESDAY, July 30 (HealthDay News) -- Using the drug
methamphetamine may increase the risk of death from a fungal lung
infection called cryptococcosis, according to the results of a new
study conducted in mice.
The condition is caused by
Cryptococcus neoformans, a fungus that initially infects the
lungs and is usually harmless in healthy people. But
methamphetamine causes openings in the blood-brain barrier than can
enable the fungus to move from the lungs and invade the central
nervous system and cause a deadly brain infection.
In this study, researchers found that injections of
methamphetamine significantly increased the colonization of the
lungs by the fungus and sped up disease progression and the time to
death in the mice.
Nine days after being infected with
C. neoformans, 100 percent of the mice that were injected
with methamphetamine were dead, compared with 50 percent of mice
that weren't given the drug, according to the study published
online July 30 in the journal
"The highest uptake of the drug is in the lungs," and this "may
render the individual susceptible to infection," study
corresponding author Luis Martinez, of Long Island University-Post
in Brookville, N.Y., and of Albert Einstein College of Medicine in
the Bronx, said in a news release from the American Society for
However, results obtained in animal studies are not always
replicated in humans.
The researchers plan to follow up on this study by investigating
how the immune system might be involved in changes that
methamphetamine causes to the blood-brain barrier.
In the United States, an estimated 13 million people have abused
methamphetamine, and there were about 353,000 regular users in in
2010, according to the news release.
The U.S. Centers for Disease Control and Prevention has more