6 | NewScientist | 25 July 2009

PARACETAMOL (acetaminophen) is an effective painkiller but a risky one, making it the leading cause of acute liver damage in the US. Now there are two ways it could get a whole lot safer. A US Food and Drug Administration panel wants to slash the recommended dosage. And a safer alternative can be made cheaply for the first time.

When used as directed paracetamol is safe, but it doesn’t take much more than the recommended dose to cause permanent, possibly fatal, liver damage. Among over-the-counter drugs, “it probably has the smallest difference between how much it takes to be effective and how much it takes to cause

damage”, says Sidney Wolfe of the watchdog group Public Citizen in Washington DC. Because paracetamol is an ingredient of numerous preparations, from

No pain, no danger cold medicines to prescription narcotics such as Vicodin, it’s easy to double-dose by mistake.

Last month the FDA’s advisory panel recommended specifying smaller doses of paracetamol and clearer labelling of medications that contain it. More controversially, the panel recommended removing it entirely from prescription narcotics. The FDA usually follows its panel’s recommendations.

A more comprehensive solution may be on the horizon, in the form of drugs such as SCP-1 , which is made up of a molecule of paracetamol joined to a saccharin molecule. In early tests in people SCP-1 does not seem to produce the same toxic by-products as paracetamol. Now Mark Trudell and colleagues at the University of New Orleans, Louisiana, together with the New Orleans company St Charles Pharmaceuticals , which ran the tests, have reported a way to synthesise SCP-1 cheaply and in large quantities (Organic Process

Research and Development, DOI: 10.1021/op900113b).

“At this point, we’re pretty much ready to go,” says Trudell.

Vaccine worries

MOVES by the US to push through a swine flu vaccine by September could halve the number of doses available there at the start of its winter flu season.

The World Health Organization estimates that by August global production of the vaccine will reach 94.5 million doses per week (Vaccine, DOI: 10.1016/j.vaccine.2009.06.034). But this estimate relies on all companies using formulations with potent adjuvants – additives to the

vaccine that boost the immune response and reduce the amount of virus needed in each dose.

However, the adjuvants have not been approved for use in the US, and there is no time for new testing. Last week the US National Biodefense Science Board advised that to make vaccine available quickly the US should stick to the well-tested formulation of the seasonal flu vaccine.

The WHO warns that if adjuvant vaccines are not “fully used” this will reduce by 40 to 50 per cent the number of doses made per week.

–Pretty much like its neighbours–

Woods lose biodiversitySOME English woodland is losing

biodiversity , even though most

individual woods contain just as

many species as before.

Comparing the plants in the

woods of Dorset, in south-west

England, with plants in the same

woods 70 years ago, Sally Keith

of nearby Bournemouth University

and her colleagues found that they

are suffering from “taxonomic

homogenisation”.

Keith visited 65 woods that had

been surveyed in detail during the

1930s, plus another 21 woods

adjacent to sites that had been

wooded 70 years ago. She found

that, on average, individual woods

contained the same number of plant

species as before – usually about

50 – but the woods have become less

distinctive and more alike.

Woods with the most species in

the 1930s contain fewer today, while

those with the least then now contain

more, she says. And across all the

woods surveyed, 117 plant species

have disappeared and only 47 new

ones have arrived. Nobody had

noticed this new facet of biodiversity

loss in the UK before, says Keith

(Proceedings of the Royal Society B,

DOI: 10.1098/rspb.2009.0938 ).

What is behind this

homogenisation? Keith says familiar

eco-villains such as climate change

and alien species are not to blame.

She believes nitrogen fertiliser

run-off, air pollution and reduced

wood clearance, resulting in fewer

clearings where distinctive species

can prosper, are behind the change.

“The molecule does not seem to produce the same toxic by-products as paracetamol”

THE moon landing celebrations are all

very well, but now it’s time for a trip

to Mars. So say Apollo 11 astronauts

Buzz Aldrin and Michael Collins .

“Sometimes I think I flew to the

wrong place,” said Collins at an event

at the Smithsonian National Air and

Space Museum in Washington DC to

celebrate the 40th anniversary of the

moon landing. “The moon is not a

particularly interesting place,” he

added. “Mars is the closest thing to

Earth’s sister that we’ve found so far.”

Head for Mars, say Apollo veterans JE

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Buzz Aldrin called for NASA to send

astronauts to Mars by 2035. “I don’t

think there’s any point in sending

human beings to the surface of the

moon and having them spend the

rest of their career there,” he said at a

briefing on 20 July. “There may be life

on Mars. If there is it’s damn sure that

we ought to go there and look at it.”

An independent review of NASA’s

plans for sending people to the moon

and Mars is due to be published at the

end of August.

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