Clarithromycin (Biaxin)
The following drug information is obtained from various newswires, published
medical journal articles, and medical conference presentations.
AIDS-related Mycobacterium avium complex
General Information
Mycobacterium avium complex (MAC) is the most common systemic
bacterial infection in subjects with advanced AIDS; it is
characterized by fever, night sweats, weight loss or wasting,
diarrhea, and abdominal pain, and is associated with a significant
number of AIDS-related deaths.
Clinical Results
Clinical trial results demonstrated that clarithomycin is
effective in reducing the risk of developing disseminated MAC
disease in subjects with advanced AIDS. In a randomized,
double-blind, placebo-controlled study conducted in the United
States and Europe, subjects with advanced AIDS (CD4 cell counts
less than or equal to 100 cells) and a negative MAC blood culture
received either clarithromycin 500 mg twice daily (n=341) or
placebo twice daily (n=341). The median duration of treatment with
clarithromycin was 10.6 months, as compared to a median duration of
8.2 months for the placebo-treated group. The risk of developing
disseminated MAC was reduced by 69 percent in the
clarithromycin-treated subject group, compared to placebo.
A statistically significant survival benefit was observed with
clarithromycin. Mortality was reduced by 31%, 31%, and 20% at 6,
12, and 18 months, respectively. Since the analysis at 18 months
includes subjects no longer receiving prophylaxis, the survival
benefit of clarithomycin may be underestimated.
Disseminated MAC developed in 19 of the 341 patients receiving
clarithromycin. Eleven of the patients developed strains of MAC
which were resistant to clarithromycin. None of the 53 MAC isolates
in the placebo group were resistant to clarithromycin.
Side Effects
The clarithromycin regimen was well tolerated by study
participants. The only adverse event significantly more common
among subjects treated with clarithromycin than placebo was taste
perversion. Other adverse events occurring in 4% of more of the
subjects taking clarithromycin include abdominal pain, diarrhea,
and vomiting.
Additional Information
While only approximately 3% of HIV-positive subjects are
diagnosed with disseminated MAC at the time of AIDS diagnosis,
studies have shown that up to 40% of these subjects show clinical
evidence of disseminated MAC within two years. In addition, MAC has
been confirmed post-mortem in up to 50 % of patients with advanced
AIDS.
Clarithromycin should not be used in pregnant women except in
circumstances where no alternative therapy is appropriate.
Calrithromycin should not be used in subjects receiving terfenadine
who have pre-existing cardiac abnormalities or electrolyte
disturbances.