Antivirals are under-prescribed in primary care in patients with shingles despite guidelines clearly advocating their use, research suggests.
It is recommended that antivirals are prescribed within 72 hours of a shingles rash appearing in people aged over 50, the immunosuppressed and those with ophthalmic zoster or other non-truncal rash.
But in the first study to look at GP prescribing for adult zoster cases, researchers found only 59% of those aged 50-64, 63% aged 65-74 and 62%aged 75-84 were given an antiviral within seven days of diagnosis. The figure for those with immunosuppression was 65%.
Antivirals were prescribed for only 50% of those with ophthalmic zoster and 31% with non-truncal zoster.
The analysis of the more than 142,000 cases over the past decade showed that although use of antivirals had increased between 2000 and 2010, there was regional variation with the north east of England and Yorkshire and Humberside having the lowest prescribing rates.
The research team at the London School of Hygiene and Tropical Medicine said it may be that GPs do not see them as ‘essential’ because they do not provide a cure especially in mild cases or that patients are presenting too late to receive treatment.
But study author Professor Liam Smeeth, an epidemiologist and GP in North London said that previous work they had done showed around 65% of patients present early so they had expected prescribing rates to be higher.
He added that there was strong evidence that they were effective in the first 48 hours but GPs may not be aware that they could actually have benefit up to seven days.
‘That is not well known and the guidance is a little unclear,’ he said.
‘Another issue may be that these drugs used to be very expensive but with generics the price has now come down considerably.’
Dr Bill Beeby, GPC clinical and prescribing chairman said the findings warranted further research but that there may be many reasons GPs might not prescribe the drugs.
He pointed out that the drugs have to be taken five times a day and in patients who present late the benefits are often marginal.
‘Often prescribers will draw upon experiences and remember these long after the guidance and guidelines have gathered dust.
‘To encourage better usage of such medications prescribers need to understand the benefit for individual patients so that they may first consider whether to prescribe and then persuade the patient of the benefit of taking the medication,’ he said.
Br J Gen Pract 2012; 62:632-633.