Outcomes assessed
Recurrence
Wiksten et al 2016 conducted a double-blind, adequately
powered RCT involving 200 patients.15 With the primary
outcome measured being recurrence within 56 days of follow
up, they found that there was no significant difference in the
recurrence rates between the two groups (penicillin and placebo
vs penicillin and metronidazole). Furthermore, no significant difference
was found in the time to recurrence or the baseline characteristics of
these patients including age, gender, smoking status or prior antibiotic
use. Similar findings were identified by Tuner et al 1986 in which all
patients in both the penicillin and placebo and the penicillin and
metronidazole group were deemed fully recovered after 10 days
of treatment.20 Every patient was treated with needle
aspiration or incision and drainage daily for the 10 days or until no
pus was drained, and the main conclusion drawn was that daily incision
and debridement along with antibiotics is the treatment of choice.
Symptoms
Wiksten et al 2016 assessed symptom duration with patient
questionnaires. The follow up of the questionnaires fell well below the
number required for statistical power, however intention to treat
analysis was used. The mean duration
of throat-related symptoms (difficult mouth opening, sore throat,
painful swallowing) was 5.3 days in the penicillin and metronidazole
group and 5.6 days in the penicillin and placebo group; this was not
statistically significant. The patients also reported on
their general physical condition and presence of pyrexia, and
these findings were not statistically different between the two groups.
Yilmaz et al 1998 conducted a double blind RCT
comparing a 10-day course procaine-penicillin alone
vs sulbactam-ampicillin.21 There were 42 patients in
total, randomly assigned however the co-morbidities or initial clinical
symptoms on presentation were not described. Both treatments were given
intramuscularly on an outpatient basis. The main resistance mechanism of
some anaerobic bacteria to beta-lactams is beta-lactamase production.
Therefore the addition of a beta-lactamase inhibitor, sulbactam, to the
ampicillin group in this instance broadens the spectrum of antibiotic
activity.22 The duration of throat pain and the time
to resumption of normal eating in both groups as measured by patient
report of symptoms was not significantly different. Axillary temperature
did also not differ significantly between the groups. Turner et al 1986
broadly described the clinical outcomes of the penicillin and placebo vs
penicillin and metronidazole as very similar between groups.
Wiksten et al 2016 also asked patients to report on symptoms associated
with adverse antibiotic effects. The study found a significant increase
in the association of nausea and diarrhoea with the penicillin and
metronidazole group compared with the penicillin and placebo
group, advocating the use of penicillin alone for the desired clinical
outcome with minimal treatment harm. Although many of the other papers
included discuss the harms of unnecessary additional treatment Wiksten
et al 2016 were the only group to formally assess the increased risk of
side effects.