Penicillin for acute sore throat: randomised double blind trial of seven days versus three days treatment or placebo in adults

Objective To assess whether treatment with penicillin for three days and the traditional treatment for seven days were equally as effective at accelerating resolution of symptoms in patients with sore throat compared with placebo.

Design Randomised double blind placebo controlled trial.

Setting 43 family practices in the Netherlands.

Participants 561 patients, aged 15-60 years, with sore throat for less than seven days and at least three of four Center criteria-that is, history of fever, absence of cough, swollen tender anterior cervical lymph nodes, and tonsillar exudate. 142 patients were excluded for medical reasons and 73 needed penicillin.

Interventions Patients were randomly assigned to penicillin V for seven days, penicillin V for three days followed by placebo for four days, or placebo for seven days.

Main outcome measures Resolution of symptoms in the first week, eradication of bacteria after two weeks, and recurrences of sore throat after two, four, and six months.

Results Symptoms resolved 1.9 and 1.7 days earlier patients taking penicillin for seven days than in those taking penicillin for three days or placebo Symptoms resolved 2.5 days earlier in patients with group A streptococci and 1.3 days earlier in patients with high colony counts of non-group A streptococci. 23 (13%) of the placebo group had to be given antibiotics later in the week because of clinical deterioration; three developed a peritonsillar abscess. The eradication rate for group A streptococci was 72% in the seven day penicillin group, 41% in the three day penicillin group, and 7% in the placebo group. Sore throat recurred more often in the three day penicillin group than in the seven day penicillin or placebo groups.

Conclusion Penicillin treatment for seven days was superior to treatment for three days or placebo in resolving symptoms of sore throat in patients with group A streptococcal pharyngitis and, possibly, in those with non-group A streptococcal pharyngitis.