Intravenous iron dispensing among Australian women of reproductive age has risen 17-fold since 2013, alongside an escalation in expenditure to more than $82 million a year and striking variation in prescribing across the country.
One in 20 Australian women aged 18 to 44 years was dispensed intravenous iron in 2024, prompting researchers to call for closer examination of whether rapidly increasing use is delivering appropriate, equitable, and high-value care.
A national population-based study found intravenous iron dispensing increased from 0.3 per 100 women in 2013 to 5.0 per 100 in 2024.
Estimated medication expenditure rose from $1.1 million to $82.3 million over the same period, with the Australian government covering 90.8% of costs in 2024.
“Underlying reasons for increasing use of intravenous iron among Australian women of reproductive age are likely multifaceted,” the researchers wrote.
“Increasing awareness of the impact of iron deficiency with or without anaemia at the clinical level coupled with the challenges, both physical and financial, of treating iron deficiency with oral iron from a patient’s perspective.
“At the same time, rapid increases in dispensing of intravenous iron and the associated escalation in costs coupled with high levels of observed treatment variation do raise questions about whether intravenous iron is being prescribed appropriately and in a cost-effective manner.”
Published in the Internal Medicine Journal, the Flinders University-led study also revealed marked variation according to age, state and territory, concession status, and prescriber type.
Iron deficiency disproportionately affects women of reproductive age, commonly because of menstrual blood loss, postpartum haemorrhage, and increased iron requirements during pregnancy and lactation.
It has been associated with impaired cognitive and physical performance and poorer quality of life, while iron deficiency anaemia in pregnancy has been linked with preterm birth, low birth weight, and reduced infant iron stores.
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Oral iron is generally first-line therapy, but adherence can be limited by nausea, abdominal pain, and constipation, while correction of anaemia and replenishment of iron stores can take time.
Intravenous iron may be preferred when oral therapy is poorly tolerated or when rapid replacement is required, including late in pregnancy or before surgery.
Researchers analysed the 10% Pharmaceutical Benefits Scheme dataset from 2013 to 2024, including all women aged 18 to 44 with an intravenous iron dispensing claim.
Four preparations were available through the PBS during the study period: iron polymaltose, iron sucrose, ferric carboxymaltose, and ferric derisomaltose. Ferric carboxymaltose was first available through the PBS in June 2014 and ferric derisomaltose in February 2019.
The researchers identified 165,516 prescriptions dispensed to 102,244 women in the dataset, corresponding to an estimated 1.66 million prescriptions nationally.
Ferric carboxymaltose drove much of the growth. It accounted for 39.6% of intravenous iron dispensings in 2014, increasing to 93.9% by 2024.
Use increased across every age group, although rates were higher among women aged 30 and older. There was also more than three-fold variation between states and territories, with Western Australia consistently recording the highest dispensing prevalence.
GPs played an increasingly prominent role, accounting for more than 60% of dispensed prescriptions in 2024. Ferric carboxymaltose accounted for 98.2% of dispensings among women’s health specialists compared with 91.1% among GPs.
Dosing patterns also changed dramatically. Overall, 87.2% of women received a dispensed treatment dose of 1000-1499mg. In 2013, 89.3% of treatment episodes involved at least 2000mg, compared with fewer than 5% in 2024.
Prescriber differences were evident, with women prescribed intravenous iron by GPs more likely to receive at least 1500mg than those treated by women’s health specialists, at 13.1% versus 4.5%.
The study also raised questions about repeat dosing. Of 149,413 women receiving ferric carboxymaltose or ferric derisomaltose, 24.7% were issued a repeat prescription, but just 7.5% of those women had the repeat dispensed.
The researchers said this could indicate that the underlying cause of iron deficiency had been addressed, removing the need for another infusion, or alternatively could represent undertreatment.
They said the substantial shift towards lower doses might also reflect earlier intravenous treatment of milder iron deficiency anaemia or increasing identification and treatment of iron deficiency without anaemia.
The rapid increase in intravenous iron use nevertheless raised questions about cost-effectiveness, according to the authors.
They said growing awareness of iron deficiency and the challenges of treating it with oral iron could help explain increasing intravenous treatment. But escalating expenditure combined with high levels of practice variation raised questions about whether intravenous iron was always being prescribed appropriately.
Equity was another concern. The proportion of women receiving intravenous iron who held a concession card declined from 30.9% in 2013 to 17.2% in 2024. Ferric carboxymaltose use was also lower among concession card holders than other women, at 88.3% versus 93.8%.
Although intravenous iron medicines are subsidised through the PBS, there is no specific MBS item covering administration costs, meaning these costs may be absorbed by public health services or passed on to women treated in the community.
The authors said this could contribute to inequitable access and argued that assessments of value should consider patient time, productivity losses, and patient-reported experiences, alongside medication and administration costs.
Safety also required consideration, with potential adverse effects of intravenous iron including hypophosphataemia, skin staining, and anaphylaxis.
The researchers cited a meta-analysis estimating hypophosphataemia in 47% of ferric carboxymaltose users compared with 4% of ferric derisomaltose users. Although often asymptomatic, severe hypophosphataemia can cause fatigue, weakness and myalgia, while repeated administration has been associated with osteomalacia and fractures.
The study could not determine individual clinical indications because PBS data did not contain information on haemoglobin or iron status, or whether treatment occurred during pregnancy. Intravenous iron administered to public hospital inpatients was also not captured, meaning total Australian use was likely underestimated.
“Underlying causes and consequences of differences in intravenous iron utilisation warrant further evaluation in order to ensure the provision of optimal and high-value clinical care,” the researchers concluded.
