Nitrofurazone sensitization

Laubstein and Niedergesass (1970) report on 24 patients with nitrofurazone sensitization. Except in one case continuation of the sensitization for 4 years could be demonstrated. The latency periods up to the manifestation of a contact allergy, were between a few weeks and 4 years. In epicutaneous tests with Nifucin, delayed reactions were seen relatively often. Group reactions against other nitrofuranes were not observed in patients sensitized by Nifucin. 

Nitrofurazone is a relatively safe topical agent. Skin sensitization has been reported. 

Nitrofurazone. S-Nitnv2-furaldchydc semicarbazont (Furacin) occurs as a lemon-yellow crystalline solid that i> sparingly soluble in water and practically insoluble in organic solvents. Nitrofurazonc is chemically stable, hut moderately light. sensitive. 

Radiosensitizing Agents - Agents which sensitize tumor cells to the lethal effects of ionizing radiation are being actively pursued. Two known radiosensitizers, metronidazole and nitrofurazone, were shown to be cytotoxic to Chinese hamster cells in the absence of radiation, but only under hypoxic conditions.82 The x-ray requirement for antitumor activity in a murine anaplastic carcinoma was reduced when metronidazole was administered orally before irradiation.83 RO-07-0582 (13), a compound... 

A recent survey by Eaton Laboratories indicates that sensitization to nitrofurazone occurs at a rate of about 1 -2 per cent. 

Neomycin, ethylenediamine, and thiabendazole have also been used as feed additives. Sulfacetamide, sulfamethazine, chlortetracycline, oxytetracycline, and bacitracin have been used as growth promoters for livestock [170]. Farmers have become allergic to both nitrofurazone and tylosin in animal feed, particularly feed for hogs. Spiramycin and tylosin were the most common sensitizers among antibiotics used by farmers in Denmark. 

However, there are reports of enzymatic nitro reduction by microsomal enzymes or by microorganisms where the reaction does not proceed in two-electron steps and where the first intermediate was described as the nitro radical anion (10, 31, 38). Peterson et al. (38) described the detection of two nitroreductases in Escherichia coli, one was oxygen-insensitive and catalyzed the two-electron-reduction of nitrofurazone, while the other one was oxygen-sensitive and catalyzed the formation of the nitrofurazone radical anion. The oxygen sensitivity of the latter reductase is due to the spontaneous reoxidation of the radical anion by molecular oxygen, which of course will play no role under anaerobic conditions. 

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