Furacin, a topical antibacterial ointment containing nitrofurazone, was pulled from the market because animal studies revealed it caused cancer. The FDA first flagged safety concerns about nitrofurazone in 1971 after new evidence showed the drug produced tumors in laboratory animals. What followed was a decades-long regulatory process that gradually removed nitrofurazone products from human use in the United States.
The Cancer Evidence That Triggered the Ban
When nitrofurazone was originally approved, it was not known to be carcinogenic. That changed when long-term feeding studies in rats and mice revealed a clear pattern of tumor growth. In two-year studies, female rats given nitrofurazone developed mammary gland tumors at dramatically higher rates than control animals. Male rats showed increases in skin tumors, tumors of the tissue lining the testes, and preputial gland tumors. Female mice developed ovarian tumors, including benign mixed tumors and granulosa cell tumors, at rates far exceeding the control groups.
Later research clarified why nitrofurazone was so dangerous. The drug’s breakdown products cause oxidative damage to DNA, specifically targeting a hotspot on the p53 gene, one of the body’s most important tumor-suppressing genes. Nitrofurazone also promotes cell proliferation, which accelerates the progression from initial DNA damage to full-blown cancer. In other words, it both starts the cancer process and speeds it along.
How the FDA Phased It Out
The FDA didn’t pull Furacin overnight. The agency began the withdrawal process in 1971, issuing formal notices that nitrofurazone and several related nitrofuran drugs had newly identified cancer risks. Rather than holding immediate hearings, the FDA worked with drug manufacturers to gather more data. By 1976, the agency issued updated notices concluding definitively that nitrofurazone was carcinogenic.
Even then, the FDA made a distinction between different nitrofurazone products. Oral nitrofurazone preparations were targeted first. The agency concluded there was “a lack of proof of safety” for these products, especially given that alternative drugs with less risk were already available. But Furacin Soluble Dressing, the topical ointment applied to burns and skin wounds, was initially allowed to remain on the market under restricted labeling. The FDA judged that for topical use, the benefits of preventing wound infection still outweighed the cancer risk, since far less of the drug would be absorbed through the skin compared to swallowing it.
Over time, however, as safer alternatives became widely available and regulatory standards tightened, the topical formulation lost its justification for continued sale. The original manufacturer was Norwich Pharmacal Company, a division of Morton-Norwich Products based in Norwich, New York.
International Restrictions
The concern about nitrofurazone was not limited to the United States. Multiple countries restricted or banned the drug. Armenia withdrew nitrofurazone tablets in 2006 and limited the compound to external application only, citing evidence of mutagenicity and carcinogenicity. The United Nations maintains nitrofurazone on its consolidated list of products that have been banned, withdrawn, or severely restricted by governments worldwide. In some countries, topical preparations containing nitrofurazone remained available longer than oral forms, following a similar pattern to the FDA’s phased approach, but restrictions have continued to spread.
Veterinary Use Restrictions
Nitrofurazone ointment has remained available in veterinary medicine, but with significant limitations. The FDA restricts its use to dogs, cats, and horses only. Federal law explicitly prohibits using nitrofurazone in food-producing animals like cattle, pigs, and poultry. Even horses treated with nitrofurazone cannot be sent to slaughter for human consumption. These restrictions exist because nitrofurazone residues in meat could expose consumers to the same carcinogenic compounds found in the animal studies.
What Replaced Furacin
Before its discontinuation, Furacin was widely used to prevent infection in burn wounds and skin grafts. It had broad antibacterial activity and was easy to apply, though it was notably ineffective against Pseudomonas, a common and dangerous wound-infecting bacterium. Several alternatives have taken its place in burn care.
- Silver sulfadiazine cream became the most common replacement. It covers a broad antibacterial spectrum, working against both Staphylococcus aureus and Pseudomonas. The tradeoff is that it forms a slough layer over wounds that makes it harder to assess how deep a burn goes, and it can’t be used indefinitely.
- Mafenide acetate solution offers broad antibacterial coverage and penetrates burn tissue effectively, making it useful for deeper wounds.
- Enzyme alginogels provide antibacterial protection while keeping the wound environment moist, and they come in formulations suited to different wound moisture levels.
The shift away from Furacin was ultimately straightforward: once these alternatives proved effective and didn’t carry cancer risk, there was no compelling reason to keep a carcinogenic drug on the market, even one that had been a staple of burn care for decades.