Areas Of Uncertainty
Distinguishing the minority of cases of acute bron-
chitis due to a treatable cause from those due to
currently nontreatable viruses i6 often challeng-
in$ Recently, the measurement of serum levels of
procalcitionin, which typically elevated in bacterial infections,
has been proposed as a means of identifying ₩ lents in whom treatment with an-
tibiotics i$ wamnted. In one clinical trial, low lev-
els of ₩ alcitonin k0.1 pg per liter) were used
to discriminate safely between patients with cough
or dyspnea who did not require antibiotic therapy,
such m those with acute bronchitis, 38 and patients
who did require such therapy. However, more data
are needed to validabe the usefulness of the pro-
calcitonin test for discriminating between patients
with bronchitis and tbose with pneumoni
AJthough clinicians might argue that the pres-
sure of dme inmces the prescribing of antibi-
otics, the data do not support this contention,
A recmt study involving almost 4000 adults witt
upper respiratory tract infections showed that th €
mean duration of an office visit was 14.2 minutes
when antibiotics were prescribed, as compared
with 15.2 mimrtes when no pres« xiption for anti·
biotics was given. 39
Www.is sa]dies involving volunteers exposed t(
ovi rus snowed that nonsteroidal drugs alom