If you or someone you care about is taking the injectable Injectafer to treat iron deficiency, you should be aware of the drug’s side effects. Although American Regent (formerly known as Luitpold Pharmaceuticals), the maker of Injectafer, informs patients about mild side effects, clinical studies have linked the drug to serious and potentially deadly outcomes from taking it.

The Risk of Hypophosphatemia

In 2016, the PLoS One medical journal featured a study of the effects of ferric carboxymaltose (FCM), which is the type of iron used in Injectafer, and iron isomaltoside 1000 (IIM), another form of iron supplement. Researchers established a link between FCM treatments and “a high risk of developing severe and prolonged hypophosphatemia” (HPP)—a risk that necessitates monitoring. The study also concluded that the risk of hypophosphatemia is “substantially lower with IIM.”

The risk of HPP from taking Injectafer increases in people with high-risk conditions, including:

  • Hyperparathyroidism
  • Vitamin D deficiency
  • Drugs that affect the ability of kidneys to eliminate medication from the body
  • Digestive conditions that interfere with the absorption of phosphate or fat-soluble vitamins

The Dangers of HPP

According to Merck Manual, HPP is an adult serum phosphate level of less than 2.5 mg/dL. Phosphate is essential to the human body’s ability to build and repair teeth and bones, as well as to the normal functioning of nerves, and to making muscles contract. When phosphate levels drop, as they do with HPP, the body suffers in these various functions.

In severe cases of the condition, patients can experience breathing difficulties, muscle weakness, anorexia, rhabdomyolysis (muscle damage), and osteomalacia (bone softening) The condition might also prompt neuromuscular disturbances, such as seizures, progress encephalopathy, coma, and death.

Other Common Injectafer Side Effects

Some side effects of taking Injectafer commonly occur in people who take the drug, according to Medical News Today. These include:

  • Dizziness
  • Constipation
  • Nausea
  • Vomiting
  • Headache
  • Low blood pressure
  • High blood pressure
  • Altered sense of taste
  • Flushing
  • Darkening of skin at injection site

The duration of these effects varies from one patient to the next. Generally, they last only a few days or weeks.

The serious side effects of taking Injectafer include HPP (as we have already discussed); severe high blood pressure; and allergic reaction.

What Has Been the Response to These Symptoms?

In February 2020, Injectafer’s warning label was beefed up to warn patients and medical professionals of the risk for symptomatic hypophosphatemia. Prior to this update, the drug’s label discussed only asymptomatic HPP.

The U.S. Food and Drug Administration (FDA) has not initiated a recall of Injectafer, however, patients who suffered HPP from their injections of the drug are taking legal action against the drug’s makers. According to these lawsuits, Luitpold Pharmaceuticals and other companies misrepresented the efficacy and safety of Injectafer.

Sara Stephens is a freelance writer who has developed a hefty portfolio of work across several industries, with a strong emphasis on law, technology, and marketing. Her work has appeared in the New York Times, as well as various technology and consumer publications, both print and online. Sara also works as a freelance book editor, having developed and edited manuscripts for bestselling and novice authors alike, and as a verbal strategist for a Miami branding consultancy.