Friday, September 23, 2011

Popular weight-loss drug under review over liver failure fears

This is ridiculous. 38 million take the drug with no harm to themselves but when just 4 people become ill it is the fault of the drug???

The most popular weight-loss drug in Britain is under investigation over fears it may be linked to liver failure. The European Medicines Agency said there had been four suspected cases of “serious liver toxicity” linked to the medicine in recent years, one of which was fatal.

Although a small number of cases considering 38 million dieters across Europe have been given the pills by doctors to lose weight, the regulator said it was now looking at what evidence there is linking the drug to liver damage. It will then decide whether or not the licences for medicines containing orlistat need to be changed or even revoked.

Orlistat, available since 1998, stops the intestines absorbing fat so it is excreted instead. It is available in an over-the-counter 60mg form, known as Alli, and a prescription-only 120mg dose, marketed as Xenical.

Official figures show that orlistat accounted for 74 per cent of the 1.45million weight-loss drugs prescribed in England in 2009, which cost £46.8m.

Two other anti-obesity pills, known as rimonabant (Acomplia) and sibutramine (Reductil), worked by altering how patients think about food but have been suspended from sale in recent years, leaving Xenical the main option for GPs to prescribe.

A Europe-wide review took place in 2009 of a possible link between orlistat and “serious hepatic reactions”, meaning liver damage, but found “insufficient evidence”. But the EMA, which licenses drugs across the continent, announced on Thursday it was looking again at the drug.

“The European Medicines Agency has started a review of orlistat-containing anti-obesity medicines, to determine whether the very rare cases of hepatic injury have an impact on their benefit-risk profile and conditions of use," it said in a statement.

“The review includes the centrally authorised prescription-only medicine Xenical (orlistat 120 mg) and the centrally authorised over-the-counter-medicine Alli (orlistat 60 mg), as well as a number of medicines containing orlistat that have either already or are in the process of being authorised at national level.”

It said the “vast majority” of reports of liver damage were not serious, and severe injuries have only been reported “very rarely”. Between August 2009 and January this year, the EMA said it had heard of 21 suspected cases of liver damage linked to the prescription-only dose of orlistat.

Four of these were severe, with one proving fatal and another requiring a liver transplant. Between 1997 and 2011 there were 21 cases where a link could have been present, out of 38m people taking the drug.

Between May 2007 and January this year there were a further nine reports of “suspected severe liver injury” linked to the lower-dose drug, but not all were conclusive and must be seen “in the context of cumulative usage in 11 million patients”.

The EMA concluded: “The Committee is now reviewing all relevant data on the risk of hepatotoxicity of orlistat-containing medicines and will issue an opinion on whether or not the marketing authorisations for these medicines should be revoked, suspended or changed.”

Roche, the pharmaceutical giant that makes Xenical, said it was the most tested diet drug there is and had been in 100 different clinical trials. But a spokesman said it would investigate any patient safety concerns.


Zinc is good for the memory... but too much could 'trigger epilepsy'

Zinc may play a key role in memory - but too much of the mineral in the brain could trigger epileptic seizures, research suggests.

A new study has found that zinc is critical to communication between neurons in the hippocampus, the brain's learning and memory centre.

Scientists used a chemical that binds to zinc to remove it from circulation in the brain's of mutant mice. Without the mineral, communication between neurons was impaired.

Lead researcher Dr James McNamara, from Duke University Medical Center in North Carolina, US, said: 'We discovered that zinc is essential to control the efficiency between two critical populations of nerve cells in the hippocampus. This addresses a long-standing controversy in the field.'

The findings were published online in the journal Neuron.

More than 50 years ago, scientists learned that high levels of zinc were contained in specialised compartments in nerve cells called vesicles.

These package the transmitter chemicals that enable nerves to communicate.

However, evidence that zinc actually played a role in cell signalling was lacking.

Over-communication by the brain cells highlighted in the study was known to occur in epilepsy, pointing to a link between zinc and the condition.

Dr McNamara said people taking zinc supplements should exercise caution.

'Carefully controlling zinc's regulation of communication between these nerve cells is critical to both formation of memories and perhaps to occurrence of epileptic seizures,' he added.


No comments: