Australian doctors are prescribing antivirals for people with the flu who may not benefit, putting patients at risk of unnecessary side effects and potentially increasing the risk of antimicrobial resistance to these medications, researchers from the University of Adelaide have found.
The large study, published in BMJ Open, investigated the prescription of antibiotics and antivirals for the management of influenza-like illness among 4.2 million patients from 550 general practices across Australia.
Researchers found antibiotics prescribing for managing suspected cases of influenza declined slightly between 2015 and 2017 in line with recommendations by Australian and international organisations to reduce antibiotic resistance.
But the use of antivirals rose from 20% to 30% in the same period, even though current recommendations state antivirals should usually be prescribed to patients at a higher risk of complications, including those affected by chronic respiratory or cardiac conditions.
Lead author Dr Carla Bernardo from the University of Adelaide's Discipline of General Practice said the study found patients at low risk of complications are receiving as many antivirals as those with chronic conditions.
"Apart from the elderly, who are more likely to have a chronic condition, the majority of children or adults receive little if any benefit from taking antivirals, the exception being those young people with underlying disease,'' Dr Bernardo said.
"It is very likely that most individuals aged under 65 do not need antivirals, although between 20-30% of them received prescriptions for these medications in our study."
Antiviral medications increase the risk of nausea, vomiting, headache, renal events and psychiatric events.
"Antivirals are recommended for the treatment of influenza for patients with chronic conditions in the community, because they shorten the length of the illness and seem to lessen symptoms and complications, such as pneumonia, bronchitis, sinusitis and ear infection.
Importantly these medications can reduce the likelihood of death by 25% among hospitalised individuals, so anything that risks the effectiveness of these medications is of concern,'' Dr Bernardo said.
"It is important to remember that the best way to prevent influenza is having the annual flu vaccine, and behavioural measures, such as staying home, hand-washing or the use of masks. These may be more cost-effective strategies to tackle the transmission of influenza among healthy people than prescribing antivirals just in case."
"Moreover, the indiscriminate use of antivirals can lead to a virus resistance as it happens with antibiotics."