NITROFURAZONE
Clinical safety rating: caution
Comprehensive clinical and safety monograph for NITROFURAZONE (NITROFURAZONE).
Nitrofurazone is a nitrofuran antibacterial agent that acts by inhibiting bacterial DNA synthesis and repair through reductive activation of the nitrofuran group. It disrupts bacterial enzymes involved in carbohydrate metabolism and inhibits acetylcoenzyme A formation.
| Metabolism | Nitrofurazone is metabolized primarily via reduction of the nitro group, leading to reactive intermediates. Metabolic pathways involve flavin-containing enzymes, including NADPH-dependent reductases. |
| Excretion | Renal: ~80% (glomerular filtration and tubular secretion); Fecal: ~10% (biliary excretion); Hepatic metabolism: ~10%. |
| Half-life | 0.3–0.5 hours (rapid metabolism and excretion; clinically short duration requires frequent dosing for local infections). |
| Protein binding | ~40% bound to plasma proteins (albumin). |
| Volume of Distribution | 0.3–0.5 L/kg (limited extravascular distribution due to rapid clearance; high tissue concentrations not achieved). |
| Bioavailability | Topical: not applicable (local application with minimal systemic absorption <1% through intact skin). |
| Onset of Action | Topical: 20–30 minutes for antimicrobial effect on wound surfaces; systemic absorption negligible for local use. |
| Duration of Action | Topical: 4–6 hours (requires reapplication to maintain bactericidal concentrations in wound exudate). |
Nitrofurazone is not systemically administered; it is used topically. For topical application, apply a thin layer to the affected area 1-2 times daily, as directed by a physician.
| Dosage form | SOLUTION |
| Renal impairment | No systemic absorption with topical use; no renal adjustment required. |
| Liver impairment | No systemic absorption with topical use; no hepatic adjustment required. |
| Pediatric use | Pediatric dosing: topical application similar to adults; apply a thin layer to affected area 1-2 times daily. Safety and efficacy in children under 2 years not established. |
| Geriatric use | Geriatric dosing: no specific adjustments required; use same topical dosing as adults. Caution in elderly due to potential for increased skin sensitivity. |
| 1st trimester | Consult provider |
| 2nd trimester | Consult provider |
| 3rd trimester | Consult provider |
Clinical note
Comprehensive clinical and safety monograph for NITROFURAZONE (NITROFURAZONE).
| Breastfeeding | Nitrofurazone is excreted into breast milk. The M/P ratio is not well established. Due to potential for hemolytic anemia in G6PD-deficient infants and possible carcinogenicity, use is contraindicated during breastfeeding. |
| Teratogenic Risk | Nitrofurazone is contraindicated in pregnancy due to evidence of fetal harm. In animal studies, it caused embryotoxicity, fetal malformations, and growth retardation. First trimester: High risk of teratogenicity; avoid use. Second and third trimesters: Fetal toxicity, including CNS and skeletal anomalies. No adequate human studies; risk outweighs potential benefit. |
■ FDA Black Box Warning
Nitrofurazone is not approved for use in food-producing animals due to carcinogenicity concerns. In humans, topical use has been associated with potential carcinogenic risk, but no FDA black box warning is issued for human use.
| Serious Effects |
["Hypersensitivity to nitrofurazone or any component of the formulation","Use in food-producing animals (FDA prohibition)"]
| Precautions | ["Potential for allergic contact dermatitis","Carcinogenicity and mutagenicity concerns based on animal studies","Not for use in food-producing animals","Avoid prolonged use on large body surface areas","May cause bacterial resistance with prolonged use"] |
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| Fetal Monitoring | If accidental exposure during pregnancy, perform detailed fetal ultrasound for congenital anomalies. Monitor maternal CBC, renal function, and hepatic enzymes. Observe neonate for hemolysis, especially if G6PD deficiency. No routine monitoring recommended due to contraindication. |
| Fertility Effects | Nitrofurazone suppresses spermatogenesis in animal studies, causing reversible infertility in males. Effects on female fertility are unknown due to lack of data. Ovarian toxicity has been observed in animal models. |