368 Section 9/ ChemotherapyAdverse effects include skin rash,
nervousness, dizziness, drowsiness, vertigo,
tremors, convulsions and psychotic state.
CAPREOMYCIN
It is a peptide protein synthesis inhibitor
antibiotic isolated from Streptomyces
capreolus. It is second line antimycobacterial
drug which exhibits activity against human
strains of Mycobacterium tuberculosis.
After oral administration, it is
insignificantly absorbed. It is administered
parenterally and is excreted unchanged by
glomerular filtration.
Adverse effects include tinnitus,
vertigo, leucopenia, hypokalemia, skin rash,
urticaria, fever, pain and induration at
injection site, excessive bleeding at injection
site and abnormalities in liver function.
KANAMYCIN
It is used in the treatment of
tuberculosis caused by streptomycin
resistant strains but since agents with lesser
toxicity e.g. capreomycin and amikacin are
available, its use is obsolete.
The pharmacology of quinolones e.g.
ciprofloxacin and ofloxacin is discussed in
chapter ‘Sulfonamides, nitrofurans and
quinolones’ and the pharmacology of
macrolide antibiotics e.g. clarithromycin
and azithromycin is discussed in chapter
‘Macrolide and polypeptide antibiotics.’RIFABUTIN
It is similar to rifampicin and shows
significant activity against M. tuberculo-
sis, M. avium complex and M. fortuitum.
Rifabutin is both substrate and cyto-
chrome 450 enzyme inducer. Because it
is less potent inducer, rifabutin is used (in
place of rifampicin) for the treatment of
tuberculosis in HIV-infected patients,
who are on concurrent antiretroviral
therapy with a protease inhibitor. It is
used alone or in combination with pyrazi-
namide.RIFAPENTINE
It is an analog of rifampicin active against
M. tuberculosis and M. avium. It inhibits bac-
terial RNA polymerase and it is a potent
inducer of cytochrome P450 enzymes.
It is indicated in the treatment of tu-
berculosis caused by rifampicin susceptible
strains.