Slim pill heart warning

A New Zealand drug watchdog says a commonly prescribed slimming pill may have life-threatening side-effects after an Auckland woman suffered a heart attack.

The 40-year-old mother of four collapsed after taking the prescription drug Reductil (sibutramine) and was resuscitated by her husband after he found her unconscious.

The woman was later found to have an undiagnosed genetic heart condition, long QT syndrome.

The woman's GP, Dr Angela Konings, reported her patient's reaction to the slimming pill to Otago University's Intensive Medicines Monitoring Programme (IMMP) which monitors suspected side-effects from prescription drugs. The results of its study - which included the Auckland woman and a further 65 cases of reported side-effects - was published this month in the British Journal of Clinical Pharmacology.

Dr Konings said the woman had recovered well and had been fitted with a pacemaker. All four of her children have since been diagnosed with the syndrome.

The link between Reductil - used by more than 17,000 Kiwis since it came on the market five years ago - and problems for people with irregular heart patterns puts GPs in a dilemma. While they can check a patient's blood pressure and family medical history, and even carry out at ECG, long QT syndrome may still not be diagnosed. For most people the risks of the drug remain unchanged.

Auckland cardiologist and arrhythmia (heart rhythm) specialist Dr Jonathan Skinner, co-author of the report, said long QT syndrome was an "occult killer" and could lie dormant for years.

"Your first presentation can be death, although usually there is a warning such as a near-miss drowning or collapse during or immediately following exercise."

As a result, people could be taking Reductil without realising they had the syndrome. The risks of side-effects worsened if the user was taking a second medication, such as an anti-depressant.

Sibutramine was withdrawn from the Italian market in 2002 for three months after it was connected to two deaths from heart problems, and 50 other cases with adverse side-effects. It was reinstated on the market after the risk-benefit ratio was considered favourable.

Though the number of people likely to be long QT syndrome sufferers is low - somewhere between one in 1000 and one in 4000 - as the use of Reductil increases so does the risk of a user suffering heart problems.

"The problem is if you don't know you have this condition, how can you safely take it?" Dr Skinner said.

He praised the IMMP for its work in linking the diet pill with long QT syndrome. "The report was sent in and they went at it like a terrier after a bone."

Praise also came from Christchurch GPs and Otago School of Medicine researchers Dr Les Toop and Dr Dee Mangin. "It's a real feather in the cap for the IMMP," Dr Toop said.

"Yet again they've been the first in the world to pick up these connections, and they have done it several times."

Dr Mangin and Dr Toop have an interest in direct-to-consumer advertising and are wary of new drugs on the market being pushed to the public. Billboards advertising Reductil appeared in shopping malls and bus shelters, and there had been ads in women's magazines, encouraging consumers to ask their GPs for the drug, Dr Mangin said.

"This diet pill is pushed as a pharmaceutical solution to weight problems which could be solved by diet and lifestyle modifications," she said.

Medsafe spokesman Stewart Jessamine said the drug's manufacturer, Abbott Australasia, had been asked to add specific warnings about long QT syndrome to the drug's data sheet.