Warning over risk of grapefruit clash with prescriptions

 

Grapefruit poses a potentially lethal health risk to increasing numbers of patients taking prescription drugs, experts have warned.

Grapefruit poses a potentially lethal health risk to increasing numbers of patients taking prescription drugs, experts have warned.

The fruit contains chemicals that can interact with certain drugs, making them more potent.

Adverse effects can include acute kidney failure, respiratory failure, internal bleeding and sudden death.

While it is well known that some patients should avoid grapefruit, or grapefruit juice, the list of drugs involved has risen sharply in recent years.

Between 2008 and 2012 the number of medications with the potential to cause serious harm by interacting with grapefruit increased from 17 to 43, said scientists writing in the Canadian Medical Association Journal.

Each year, more than six of these drugs on average were being made available to patients.

Dr David Bailey, from Lawson Health Research Institute in London, Ontario, and colleagues described the trend as “disturbing”.

They wrote: “Unless healthcare professionals are aware of the possibility that the adverse event they are seeing might have an origin in the recent addition of grapefruit to the patient's diet, it is very unlikely that they will investigate it.

“In addition, the patient may not volunteer this information. Thus, we contend that there remains a lack of knowledge about this interaction in the general healthcare community.”

More than 85 drugs in total can interact with grapefruit, and of these 43 can have serious side effects, said the researchers.

Other citrus fruits such as Seville oranges, used to make marmalade, and limes contained the same active ingredients that caused the drug interactions.

The chemicals, called furanocoumarins, act on an enzyme in the gut that normally reduces the potency of medication. This can effectively boost the dose of some drugs many times.

The list of danger medicines includes treatments for anxiety, depression, allergy, HIV infection, seizures, heart rhythm abnormalities and high cholesterol.

A modest single helping of grapefruit can have an effect even if consumed hours before a drug is taken, said the scientists.

Frequent exposure to grapefruit could make matters worse. Combining the cholesterol-lowering drug simvastatin with a 200 millilitre glass of grapefruit juice once a day for three days more than tripled its concentration level.

Older people with a reduced ability to tolerate drug overdoses were at greatest risk.

“The current trend of increasing numbers of newly marketed grapefruit-affected drugs possessing substantial adverse clinical effects necessitates an understanding of this interaction and the application of this knowledge for the safe and effective use of drugs in general practice,” the experts concluded.

Start your day with The Independent, sign up for daily news emails
ebooks
ebooksAn introduction to the ground rules of British democracy
Latest stories from i100
Have you tried new the Independent Digital Edition apps?
SPONSORED FEATURES
Independent Dating
and  

By clicking 'Search' you
are agreeing to our
Terms of Use.

iJobs Job Widget
iJobs General

Recruitment Genius: Administrative Assistant / Order Fulfilment

£14000 per annum: Recruitment Genius: An exciting opportunity to join a thrivi...

SThree: Trainee Recruitment Consultant

£18000 - £23000 per annum + Uncapped OTE: SThree: Trainee Recruitment Consulta...

SThree: Trainee Recruitment Consultant

£18000 - £23000 per annum + Uncapped OTE: SThree: Trainee Recruitment Consulta...

Recruitment Genius: Production Operative

£13000 - £17000 per annum: Recruitment Genius: Due to a period of sustained an...

Day In a Page

Refugee crisis: David Cameron lowered the flag for the dead king of Saudi Arabia - will he do the same honour for little Aylan Kurdi?

Cameron lowered the flag for the dead king of Saudi Arabia...

But will he do the same honour for little Aylan Kurdi, asks Robert Fisk
Our leaders lack courage in this refugee crisis. We are shamed by our European neighbours

Our leaders lack courage in this refugee crisis. We are shamed by our European neighbours

Humanity must be at the heart of politics, says Jeremy Corbyn
Joe Biden's 'tease tour': Could the US Vice-President be testing the water for a presidential run?

Joe Biden's 'tease tour'

Could the US Vice-President be testing the water for a presidential run?
Britain's 24-hour culture: With the 'leisured society' a distant dream we're working longer and less regular hours than ever

Britain's 24-hour culture

With the 'leisured society' a distant dream we're working longer and less regular hours than ever
8 best children's clocks

Tick-tock: 8 best children's clocks

Whether you’re teaching them to tell the time or putting the finishing touches to a nursery, there’s a ticker for that
Isis profits from destruction of antiquities by selling relics to dealers - and then blowing up the buildings they come from to conceal the evidence of looting

How Isis profits from destruction of antiquities

Robert Fisk on the terrorist group's manipulation of the market to increase the price of artefacts
Labour leadership: Andy Burnham urges Jeremy Corbyn voters to think again in last-minute plea

'If we lose touch we’ll end up with two decades of the Tories'

In an exclusive interview, Andy Burnham urges Jeremy Corbyn voters to think again in last-minute plea
Tunisia fears its Arab Spring could be reversed as the new regime becomes as intolerant of dissent as its predecessor

The Arab Spring reversed

Tunisian protesters fear that a new law will whitewash corrupt businessmen and officials, but they are finding that the new regime is becoming as intolerant of dissent as its predecessor
King Arthur: Legendary figure was real and lived most of his life in Strathclyde, academic claims

Academic claims King Arthur was real - and reveals where he lived

Dr Andrew Breeze says the legendary figure did exist – but was a general, not a king
Who is Oliver Bonas and how has he captured middle-class hearts?

Who is Oliver Bonas?

It's the first high-street store to pay its staff the living wage, and it saw out the recession in style
Earth has 'lost more than half its trees' since humans first started cutting them down

Axe-wielding Man fells half the world’s trees – leaving us just 422 each

However, the number of trees may be eight times higher than previously thought
60 years of Scalextric: Model cars are now stuffed with as much tech as real ones

60 years of Scalextric

Model cars are now stuffed with as much tech as real ones
Theme parks continue to draw in thrill-seekers despite the risks - so why are we so addicted?

Why are we addicted to theme parks?

Now that Banksy has unveiled his own dystopian version, Christopher Beanland considers the ups and downs of our endless quest for amusement
Tourism in Iran: The country will soon be opening up again after years of isolation

Iran is opening up again to tourists

After years of isolation, Iran is reopening its embassies abroad. Soon, there'll be the chance for the adventurous to holiday there
10 best PS4 games

10 best PS4 games

Can’t wait for the new round of blockbusters due out this autumn? We played through last year’s offering