Approximately one person in 10 taking diet drug Acomplia (rimonabant) experiences psychiatric side effects and about one person in 100 experiences suicidal thoughts, according to U.K. regulators.

Of some 41,000 patients treated with rimonabant since it was launched in the U.K. in June 2006, 364 “psychiatric reactions have been reported,” the Department of Health’s Medicines and Healthcare Products Regulatory Agency (MHRA) said on July 19th.

“Amongst these, there have been 48 reports of depression, 16 reports of suicidal thoughts and one report of self-injury,” the regulatory agency said.

The MHRA said evidence suggested one person in 10 taking Acomplia may develop psychiatric side effects, and “approximately one patient in every 100 may experience suicidal thoughts.”

The MHRA advised: “If you start to experience symptoms of depression while taking Acomplia, or if you are currently being treated with antidepressants, consult your doctor.

“If you have had depression in the past but feel well on Acomplia, you should continue treatment with Acomplia and discuss your treatment with your doctor at your next routine appointment.”

The European Medicines Agency, however, took a more aggressive approach, deciding that Acomplia can remain on the market but with tougher warnings against its use by persons with major depression or anyone on an antidepressant.

The EMEA’s Committee for Medicinal Products for Human Use (CHMP) said “too many patients are taking Acomplia at the same time as antidepressants, even though Acomplia is not recommended for use in patients also taking antidepressants.”

While the CHMP said “Acomplia must no longer be used in these patients,” it concluded “that the benefits of Acomplia continue to outweigh its risks, except in patients with ongoing major depression or taking antidepressants.”

The European Medicines Agency (EMEA) recommended contraindicating Acomplia (rimonabant) from sanofi-aventis, in patients with ongoing major depression or who are being treated with antidepressants, because of the risk of psychiatric side effects. Doctors in the EU have already been warned about this since June 2006 but the Agency’s Committee for Medicinal Products for Human Use (CHMP) has now recommended upgrading this warning.