Current issues of ACP Journal Club are published in Annals of Internal Medicine


Penicillin V and amoxicillin improved health status in sinusitis

ACP J Club. 1997 Jan-Feb;126:10. doi:10.7326/ACPJC-1997-126-1-010

Source Citation

Lindbaek M, Hjortdahl P, Johnsen UL. Randomised, double blind, placebo controlled trial of penicillin V and amoxycillin in treatment of acute sinus infections in adults. BMJ. 1996 Aug 10;313:325-9.



To determine the effectiveness and safety of amoxicillin and penicillin V for adults with acute sinusitis.


Randomized, double-blind, placebo-controlled trial.


General practices in southern Norway.


130 adults (mean age 39 y, 65% women) who had sinusitis confirmed by computed tomography (CT) were studied. Exclusion criteria were age ≤ 15 years, pregnancy, antibiotic or immunosuppressive treatment, previous nose or sinus surgery, alcohol or drug abuse, rheumatic disease, allergy to penicillin, symptoms for > 30 days, high fever, or excessive pain. 91% of patients completed treatment.


Patients were allocated to penicillin V, 1320 mg 3 times/d (n = 41); amoxicillin, 500 mg 3 times/d (n = 45); or placebo (n = 44). Medication was taken for 10 days. Nasal decongestants and paracetamol were allowed.

Main outcome measures

Patient-reported health status on days 3 and 10 and duration of illness, clinician-reported symptoms and signs, CT results, and adverse effects.

Main results

Analysis was by intention to treat. At day 10, patients receiving antibiotics reported higher rates of feeling substantially better. 56% for patients receiving placebo compared with 89% of patients receiving amoxicillin (P < 0.001) reported feeling substantially better. {The 25% absolute risk improvement (ARI) means that 3 patients would need to be treated with amoxicillin (compared with placebo) for 10 days to have 1 additional patient report feeling better, 95% CI 2 to 7; the relative risk improvement (RRI) was 56%, CI 21% to 113%.}* The results were similar for penicillin: 56% of patients receiving placebo compared with 82% of patients receiving penicillin reported feeling better at 10 days {P = 0.004; ARI, 26%; NNT 4, CI 2 to 18; RRI 44%, CI 8% to 99%}.* Clinical severity and CT at day 10 also showed similar results. The groups receiving antibiotics had more diarrhea (P = 0.001) and vaginal discharge (P = 0.05) than the group receiving placebo, but the groups did not differ for other adverse effects.


Penicillin V and amoxicillin were more effective than placebo for improving health status in adults with confirmed sinusitis. Both antibiotics also produced increased rates of mild adverse effects.

Sources of funding: Norwegian Research Council and Apothekernes Laboratorium A/S (medications).

For article reprint: Dr. M. Lindbaek, Department of General Practice, University of Oslo, Box 1130, Blindern, N-0317, Oslo, Norway. FAX 47-2285-0650.

*Numbers calculated from data in article.


This important study by Lindbaek and colleagues confirms the efficacy of antibiotic therapy for acute sinusitis in adults. Antibiotics have been shown to be superior to placebo in children (1), but the only previous applicable trial done in adults (2) was not placebo-controlled. This trial is methodologically strong: All outcomes were determined blindly, and strict CT criteria were used to diagnose sinusitis. Air-fluid levels and complete sinus opacification are very specific signs of bacterial sinusitis (3).

The patients in both antibiotic groups improved substantially more than did the patients in the placebo group according to all outcomes determined. In most of these measures, the amoxicillin group fared slightly better than the penicillin group, but in no case were these differences significant. This is somewhat surprising because Hemophilus influenzae is one of the most common causes of sinusitis (3), and penicillin is frequently inactive against this organism (4). This Norwegian community may have had H. influenzae with resistance patterns different from those of many other communities: 15 of 16 nasopharyngeal cultures of H. influenzae were sensitive to penicillin. It is reasonable to continue the common practice of prescribing amoxicillin (high-dose penicillin V in Scandinavia) as first-line treatment for suspected acute bacterial sinusitis in adults.

Laura Rees Willett, MD
Robert Wood Johnson Medical SchoolNew Brunswick, New Jersey, USA

Laura Rees Willett, MD
Robert Wood Johnson Medical School
New Brunswick, New Jersey, USA


1. Wald ER, Chiponis D, Ledesma-Medina J. Comparative effectiveness of amoxicillin-clavulante potassium in acute paranasal sinus infections in children. A double-blind, placebo-controlled trial. Pediatrics. 1986; 77:795-800.

2. Axelsson A, Chidekel N, Grebelius N, Jensen C. Treatment of acute maxillary sinusitis. A comparison of four different methods. Acta Otolaryng. 1970;70:71-6.

3. Willett LR, Carson JL, Williams JW. Current diagnosis and management of sinusitis. J Gen Intern Med. 1994;9:38-45.

4. Yao JD, Moellering RC. Antibacterial agents. In: Murray PR, ed. Manual of Clinical Microbiology. Washington, DC: ASM Pr; 1995:1282.