Even as the European Medicines Agency (EMEA) warned patients on anti-depressants against taking weight loss drug rimonabant, the Department of Health's Medicines and Healthcare products Regulatory Agency (MHRA) in UK said it had received reports of psychiatric reactions to drug, marketed as Acomplia.
"Three hundred and sixty-four (364) psychiatric reactions have been reported," it said. "Amongst these, there have been 48 reports of depression, 16 reports of suicidal thoughts and one report of self-injury."
It said evidence suggested one in 10 people who take Acomplia may develop psychiatric side effects.
"Approximately one patient in every 100 may experience suicidal thoughts."
About 41,000 patients in the UK have been treated with rimonabant since it was launched there in June 2006. Acomplia is manufactured by Sanofi-aventis, world's fourth largest drug-makers.
The drug is being appraised by the National Institute for Health and Clinical Excellence (Nice) for use on the NHS.
However, it already has a European licence, meaning GPs can prescribe it to patients while they wait for final guidance from Nice.
Rimonabant targets a natural body system that governs a host of factors controlling appetite, weight, metabolism and energy use. It also works to combat the craving for nicotine, and was launched at a cost of Ģ55.20 per patient per month.
In trials involving more than 6,000 patients in the US and Europe, around a quarter of those taking rimonabant lost more than 10 per cent of their initial body weight after a year. About half lost more than five per cent of their body weight.
Waist circumference, seen by many experts as a more important measurement, dropped by between 6cm-7cm.
One in five adults in the UK - almost 10 million people - is clinically obese.
The EMEA has said doctors in the European Union had been warned "of the risk of psychiatric side-effects" since June 2006 but it was now upgrading this warning. Any patient who develops depression while on the drug should stop the treatment, the EMEA said in its recommendation.
An EMEA statement said that Accomplia has been authorised in the EU since June 2006 "for the treatment of obese or overweight adult patients".
It noted added that the product information with the drug did carry a warning "that doctors should not prescribe Acomplia in patients with uncontrolled serious psychiatric conditions such as major depression".
After perusal of all the data made available by Sanofi-aventis on the drug's psychiatric side-effects, Agency's Committee for Medicinal Products for Human Use (CHMP) "concluded that the benefits of Acomplia continue to outweigh its risks, except in patients with ongoing major depression or taking anti-depressants".
Sanofi-aventis said Acomplia labelling had been updated based on data from one year of post-marketing experience and five additional clinical trials completed since June 2006.
"With this updated labelling, Acomplia is now contra-indicated in patients with ongoing major depressive illness and/or ongoing anti-depressive treatment," the statement said.
Last month, a committee advising the Food and Drug Administration (FDA) in the United States voted to ban the drug because of an increased risk of suicide