FDA adds a boxed warning to ferric carboxymaltose (Injectafer) for symptomatic low phosphate

Legal effect

What this establishes

• FDA approved labeling revisions adding a boxed warning for symptomatic hypophosphatemia with ferric carboxymaltose injection.
• FDA recommends checking serum phosphate before a repeat course in patients at risk of low phosphate or when a repeat course is planned within three months, correcting pre-existing hypophosphatemia before treatment, and considering permanent discontinuation for severe or persistent hypophosphatemia.
• FDA reports that symptomatic cases continued despite 2020 and 2023 warnings, and that Sentinel data show phosphate testing in fewer than 20% of administration episodes.
• Symptoms can include muscle weakness or pain, fatigue, tremor, confusion, seizures and arrhythmia; chronic severe hypophosphatemia can lead to osteomalacia and fractures.

What this does not establish

• A withdrawal or recall of the product.
• That other intravenous iron products carry the same boxed warning.
• Any change to the approved indications.

Why it matters

Low phosphate symptoms can look like the iron deficiency the infusion is treating. A boxed warning moves a known risk to the most prominent place on the label; whether practice changes depends on whether phosphate is actually checked.

Primary source

• FDA Drug Safety Communication, 1 September 2026

Related on this site

• Medication safety in fragmented systems
• Medication side effect, allergy or intolerance

Register: the record store · record id fda-injectafer-boxed-warning-2026-09-01.