Doctors cut cancer drug that can cause deadly heart disease

The drug ondansetron is used to relieve nausea associated with chemotherapy treatment, but evidence suggests that it can trigger cardiac arrhythmia – an irregular heartbeat that can be fatal.

Scotland’s chief pharmaceutical officer, Bill Scott, has issued a warning to Scottish health boards and doses prescribed to patients have been cut in half.

The drug, also known by the brand name “Zofran”, was the subject of a warning by United States authorities a year ago.

The makers, GlaxoSmithKline, were told to carry out checks on the drug and report back.

Having received the results of the study, the US Food and Drug Administration (FDA) has now said that the recommended dose should be slashed from 32mg to 16mg.

The study found a firm link between high doses of ondansetron, which is taken by drip or in tablet form, and changes in the electrical activity of the heart.

These changes can lead to  an irregular heartbeat which  can kill patients undergoing chemotherapy.

Labour health spokeswoman Jackie Baillie said: “This will be very concerning to those receiving treatment for cancer – not to mention those who have been treated in the past.

“It is essential that we have an investigation into what the consequences of this dose being used for so long are, and whether it has caused anyone in Scotland any harm. We also need to know if there has been a problem for some time, and if so, did the government know?”

The Scottish Conservatives also called for an inquiry into the history of the findings.  A spokesman said: “Patients  affected by this decision will naturally be concerned and it is imperative they are given as much information and support as possible from medical staff.

“The Scottish Government has duty to reveal as soon as possible how many people have been put at risk.”

The FDA said on its website: “Preliminary results from a recently completed clinical study suggest that a 32mg single intravenous dose of ondansetron may affect the electrical activity of the heart, which could pre-dispose patients to develop an abnormal and potentially fatal heart rhythm known as ‘Torsades de Pointes’. “FDA will evaluate the final study results when available, and will work with GSK to explore an alternative single dose regimen that is both safe and effective. A Scottish Government spokesperson said: “Advice was issued about reducing the recommended dose of this drug. This was followed up immediately by the Scottish Government who issued guidance to pharmacists and GPs to ensure they were aware.