Researchers found that patients taking amoxicillin had no better symptom relief than those on placebo. They said the findings added to mounting evidence that antibiotics provided 'little if any benefit' to patients with acute sinusitis.

Antibiotics are still prescribed for around 90% of sinus infections in the UK despite NICE advice not to do so or to issue delayed prescriptions in case symptoms worsen.

The researchers, from Washington University School of Medicine in St Louis, Missouri, said concern over antibiotic resistance suggested such practices need reviewing.

They argued that strong evidence of symptom relief was needed to justify antibiotic prescribing for a condition which is usually self-limiting.

The researchers randomised 166 adults to a 10-day course of amoxicillin 500mg three times daily or placebo.

All patients were given a five- to seven-day supply of symptomatic treatments for pain, fever, cough, and nasal congestion.

After 10 days, quality-of-life scores had improved by the same amount whether patients took amoxicillin or placebo. Both groups missed the same number of days of work, and had identical relapse rates and recurrence after four weeks.

The researchers said the findings supported NICE’s emphasis on delayed prescribing. Since acute sinusitis resolves after around two-and-a-half weeks, this approach may mean antibiotics are not needed, they said.

But authors said the study did not include patients with symptoms of serious complications, whom may need to be managed differently.