antibioticsbooks

162 PART 3 Antimycobacterial Drugs
and can rarely precipitate gout, leading to withdrawal
of pyrazinamide from the regimen and an
extension of the duration of tuberculosis therapy.
Arthralgias also occur and are separate from
hyperuricemia; these can be managed with overthe-counter
pain medications.
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Important Facts
• Interestingly, pyrazinamide is active only in
acidic environments (pH , 6). This would be
problematic for some diseases, but it is perfect
for the caseous granulomas that active tuberculosis
forms. It also works intracellularly in
phagocytes.
• Pyrazinamide is no longer used in combination
with rifampin as an alternative for latent
tuberculosis because of high rates of hepatitis.
• Be careful not to confuse this drug with pyridoxine,
which most patients with tuberculosis
should also be taking.
What It’s Good For
Pyrazinamide’s only use is in the initial phase of
active tuberculosis treatment.
Don’t Forget!
Tell your patients to report any signs of hepatitis
(dark urine, abdominal pain, loss of appetite) when
they are on pyrazinamide or any first-line tuberculosis
therapy.