Calls for stronger warnings on iron infusion risks after woman's induced coma

A 46-year-old woman is calling for stronger warnings on the risks associated with iron infusions after a treatment left her in an induced coma with a condition that causes dangerously low phosphate levels in the blood.

Kate Russell said she was not warned about the potential risks of iron infusions and the 12 months since her admission to Toowoomba Hospital's intensive care unit (ICU) had been "devastating".

Diagnosis and treatment

Ms Russell said she was diagnosed with severe hypophosphataemia – dangerously low phosphate in the blood – which can occur after an iron infusion.

"[I had] countless specialist appointments and medications, as well as using up all my personal leave and having to give up parts of my role [as a teacher]," she said.

"It's taken a huge financial toll on my family."

Kate Russell says she was active before getting an iron infusion.

She said the only risk associated with an iron infusion she was told about was iron staining on her arm where the intravenous needle was inserted.

But Ms Russell said she started experiencing muscle weakness and heart palpitations after her treatment in October last year, and she continued to deteriorate for a month before she collapsed in a doctor's surgery and was rushed to hospital.

"I just could not continue to breathe, so they decided that they needed to take over my breathing and intubate me," she said.

She said when the cause of her illness was identified, she was given phosphate replacement therapy.

Rising cases of hypophosphataemia

Medical experts say hypophosphataemia is a complication that can occur with the use of ferric carboxymaltose, an intravenous iron preparation commonly administered in Australia.

Recent data shows it is becoming more common as iron infusions surge across Australia, particularly among women of reproductive age.

Bond University assistant professor and general practitioner Kieran Le Plastrier said several patients had presented to his practice feeling "generally unwell" after receiving iron infusions this year and blood tests had shown they all had low phosphate.

"They felt really, really terrible at a time when they're expecting to feel really great because we've done the iron infusion," he said.

Dr Le Plastrier said ferric carboxymaltose caused hypophosphataemia by preventing the breakdown of a hormone, which in turn signalled the kidneys to excrete more phosphate than usual.

"All versions of infusions can do it, but this particular product has a high rate because it blocks the conversion of certain cofactors in the gut and in the blood from being able to recycle and absorb phosphate," he said.

"Phosphate turns over every day; we excrete it in our kidneys and in our stool and this product can actually cause that to increase significantly."

US warning and Australian response

Last month, the US Food and Drug Administration (FDA) brought in its strongest safety warning, a boxed warning, for ferric carboxymaltose due to the risks of hypophosphataemia.

Royal Australian College of General Practitioners (RACGP) co-deputy chair Aadhil Aziz said Australian regulators should consider following the US to ensure patients and healthcare professionals were better informed about the potential risk.

"Having a warning doesn't mean that you don't do this," Dr Aziz said.

"It just means that you're paying more attention to the phosphate and I don't think that's a bad thing."

He said patients should discuss dietary changes or oral iron tablets with their regular doctor before opting for an iron infusion.

For patients who required intravenous iron, he said checking phosphate levels before treatment could also help identify potential risk factors.

"We want our Australian patients to be safe and by focusing on safety first, making sure that this doesn't happen and what can be prevented is prevented," Dr Aziz said.

Recovery and warning

Meanwhile, Ms Russell said it had taken her almost a year to recover, and she had only recently returned to work full-time as a physical education teacher.

She urged anyone thinking about getting iron infusions to do their research before getting the treatment.

"Look out for these symptoms post-iron infusion. If you experience it, go straight back to your GP," she said.

"I don't think anyone should have to experience this."