3.4. AIDS and Opportunistic Infections: PCP: The Most Common OI
Description
This article is from the AIDS FAQ, by Dan Greening with numerous contributions by others.
3.4. AIDS and Opportunistic Infections: PCP: The Most Common OI
PCP remains the most common, life-threatening opportunistic infection
in people with HIV, occurring in up to 80 percent of individuals who
do not take preventive therapy.
The PCP organism, a microscopic parasite, appears to infect most
people during childhood. In people with healthy immune systems, the
parasite normally remains dormant, but it may cause disease in those
with damaged immune systems.
PCP infection is characterized by a dry cough and shortness of
breath. Individuals may experience other, less specific symptoms such
as fever, fatigue and weight loss for weeks or even months before
respiratory problems appear. As PCP infection progresses, the
functioning lung tissue becomes clogged, which decreases the transport
of oxygen from the inhaled air into the blood. At this point, the
oxygen in the blood may be lowered to dangerous or even fatal levels.
Without treatment, close to 100 percent of HIV-infected patients with
PCP die. During the 1980s, the development of effective therapies led
to better management of PCP. Drugs for preventing and treating PCP
include aerosolized pentamidine and oral trimethoprim-sulfamethoxazole
(TMP/SMX), but both can result in serious side effects that prevent
some patients from taking the drugs.
TMP/SMX is recommended more often than aerosolized pentamidine for
treating and preventing PCP because the combination is effective,
tolerated by about half of the patients who take it and may work
against other disease-causing organisms as well. In 1992, an
NIAID-supported trial proved that TMP/SMX is better than aerosolized
pentamidine at preventing a second episode of PCP in people with AIDS
who can tolerate either therapy.
Although definitive research data are lacking, other agents may be
considered in situations in which neither TMP/SMX nor aerosolized
pentamidine can be given. The drug atovaquone is approved for patients
with mild to moderate PCP who cannot tolerate TMP/SMX. One NIAID study
showed that primaquine, an antimalaria drug, with clindamycin is an
effective oral therapy for PCP. TMP with dapsone is an alternative
treatment.
The search for new, more effective, less toxic drugs and combinations
of drugs to fight PCP continues. NIAID studies play an important role
in this effort. One trial compares three drug regimens--TMP/dapsone,
primaquine/clindamycin and TMP/SMX--for oral treatment of mild to
moderate PCP. Another protocol looks at an 8-aminoquinoline, an
antimalaria drug, while a third trial considers two regimens of
TMP/SMX to prevent PCP.
Continue to:
My Books
