This study will compare the symptom relief provided by 5 cold medicines versus the symptom relief provided by the same 5 cold medicines plus the antibiotic, amoxicillin, in people who have sinus infections. Treatment with amoxicillin may be more effective than treatment with cold medicines alone. Two hundred adult volunteers, aged 18 to 70 years old, with sinus infections will participate in this study for 28 days. Volunteers will receive a 10-day course of either amoxicillin or placebo (substance containing no medication). In addition, all volunteers will receive pain medication, a chest decongestant, nasal decongestants, and cough medicine as needed. Volunteers will be interviewed by telephone on days 0, 3, 7, 10, and 28 following the start of treatment. The study will look at quality of life factors such as change in functional status (ability to perform daily activities) and symptoms, recurrence of the infection, satisfaction with care, and the direct costs of treatment.

The primary objective of this phase IV, randomized, placebo controlled clinical trial is to determine the incremental effect of amoxicillin treatment compared with symptomatic treatments on disease-related quality of life in adults with clinically diagnosed acute bacterial rhinosinusitis. The secondary objective is to determine the incremental effect of amoxicillin treatment compared with symptomatic treatments on functional status, symptoms, disease recurrence, satisfaction with treatment, and direct costs of treatment in adults with clinically diagnosed acute bacterial rhinosinusitis. The tertiary objective is to identify prognostic indicators for clinical improvement with antibiotic treatment in adults with clinically diagnosed acute bacterial rhinosinusitis. Two hundred adult subjects, 18 to 70 years old, who meet the recommended criteria for acute bacterial rhinosinusitis, will be enrolled from 8 practice sites. Subjects will be randomized to receive a 10-day course of either amoxicillin or placebo. In addition, all subjects will receive an analgesic, an oral decongestant, a nasal saline spray, and an antitussive agent. Subject outcomes will be assessed by telephone interview at 0, 3, 7, 10, and 28 days. The primary outcome is the disease-specific quality of life at Day 3 measured with the SNOT-16, a validated evaluative instrument. Secondary outcomes include change in functional status and symptoms, disease recurrence, satisfaction with care and the direct costs of treatment. Tertiary outcome measures include possible subject and disease-related factors that predict clinical improvement with antibiotic treatment at Day 3 for use in future studies to aid clinical decision-making.

Inclusion Criteria:

1. The subject must be male or female, and between the ages of 18 and 70 years old.
2. The subject must have symptoms of acute bacterial rhinosinusitis.
3. The subject must be attending a participating primary care practice in the community.
4. The subject must have symptoms of acute bacterial rhinosinusitis self-assessed as moderate, severe, or very severe.
5. The subject must have access to a phone.

Exclusion Criteria:

1. The subject is less than 18 years old or more than 70 years old.
2. The subject has very mild or mild symptom severity assessed by self report.
3. The subject has an allergy to penicillin or amoxicillin.
4. The subject has received antibiotic therapy within the past 4 weeks (including chronic treatment for acne and low dose prophylactic treatment).
5. The subject has complications of sinusitis (facial edema, cellulitis, or orbital, meningeal or cerebral signs).
6. The subject is thought to require intravenous antibiotics or hospital admission.
7. The subject is pregnant. (This will be assessed by self-report. A pregnancy test will not be required).
8. The subject has a comorbidity that may impair their immune response (such as immunodeficiency disease, uncontrolled cancer, or chemotherapy or radiation treatment).
9. The subject has cystic fibrosis.
10. The subject has Type I diabetes or is taking insulin to treat diabetes.
11. The subject had prior sinus surgery.
12. The subject requires an antibiotic for a concurrent condition such as an ear infection.
13. The subject is not able to complete the study protocol because of language barriers, lack of telephone access, or other issues.
14. Any other condition that the provider feels may interfere with the study.