TRIALS SHOW THAT Tamiflu, the antiviral drug, reduces the length of symptoms, complications and hospital admissions from the flu.

That’s according to the results of the most thorough analysis of oseltamivir (which is marketed as Tamiflu) data to date, which has been published by the Lancet.

The drug has been the subject of some controversy, with one study last year finding that there was “reason to question the stockpiling of the drug, its inclusion on the WHO list of essential drugs, and its use in clinical practice as an anti-influenza drug”.

New research

In this latest study, the data suggests that:

• The drug shortens the duration of flu symptoms by about a day, compared to placebo, in adults with laboratory-confirmed influenza.
• Tamiflu significantly reduces the risk of influenza complications requiring antibiotics (such as pneumonia)
• It also reduces hospitalisations in adults infected with influenza.

The study was conducted by an independent research group led by Arnold Monto, Professor of Epidemiology at the University of Michigan School of Public Health, USA, and Stuart Pocock, Professor of Medical Statistics at the London School of Hygiene & Tropical Medicine, UK.

Trials

They and their colleagues analysed data from nine trials comparing the licensed 75mg dose of oseltamivir with a placebo for the treatment of seasonal influenza in 4328 adults between 1997 and 2001.

What did they find?

• That treating adults with influenza with oseltamivir reduced the duration of symptoms by 21% compared with placebo (from 123 hours to 98 hours).
• However, no benefit was noted in adults without influenza virus infection.
• Oseltamivir treatment results in a significantly increased risk of nausea (absolute increase 3.7%) and vomiting (4.7%) compared with placebo.

They found that though rates of complications were low, oseltamivir reduced the risk of lower respiratory tract infections requiring antibiotics more than 48 hours after study entry by 44% compared with placebo (4.9% vs 8.7%), and hospital admission for any cause by 63% (0.6% vs 1.7%) in adults with laboratory-confirmed influenza.

Monto noted: “The safety and effectiveness of oseltamivir has been hotly debated, with some researchers claiming there is little evidence that oseltamivir works.”

He continued:

Our meta-analysis provides compelling evidence that oseltamivir therapy reduces by one day the typical length of illness in adults infected with influenza and also prevents complications and reduces the number of people needing hospital treatment. Whether the magnitude of these benefits outweigh the harms of nausea and vomiting needs careful consideration.

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