What drugs are used to kill rats? - briefly
Common rodenticides comprise anticoagulant baits—bromadiolone, brodifacoum, difenacoum—and acute poisons such as zinc phosphide and sodium fluoroacetate. They are supplied as bait formulations and subject to strict regulatory controls to limit exposure of non‑target wildlife.
What drugs are used to kill rats? - in detail
Rodent‑targeted pharmaceuticals fall into several chemical families, each with a distinct mode of action and regulatory profile.
Anticoagulant rodenticides block vitamin K recycling, causing fatal internal bleeding. First‑generation compounds such as warfarin require multiple feedings; second‑generation agents—bromadiolone, difenacoum, brodifacoum, and chlorophacinone—are effective after a single dose because of higher potency and longer half‑life. Typical bait concentrations range from 0.005 % to 0.025 % active ingredient, formulated in grain or wax blocks. Resistance to first‑generation agents has prompted widespread adoption of second‑generation formulations, though regulatory agencies limit their use to certified applicators in many jurisdictions.
Metal phosphides release phosphine gas when ingested, producing rapid systemic toxicity. Zinc phosphide is the most common, supplied as pellets or coated bait. Recommended loading is 0.05 %–0.1 % zinc phosphide, delivering lethal exposure within 24 hours. Use is restricted to outdoor environments because phosphine gas poses inhalation hazards to non‑target species and humans.
Cholecalciferol (vitamin D₃) induces hypercalcemia, leading to kidney failure and cardiac arrest. Commercial products contain 0.025 %–0.05 % cholecalciferol, requiring a single consumption to achieve mortality. This class is favored where secondary poisoning risk is low, as mammals metabolize excess calcium more efficiently than rodents.
Sodium fluoroacetate (1080) interferes with the citric‑acid cycle, causing cellular energy collapse. Formulations are typically 0.05 %–0.1 % in bait matrices. Due to its high toxicity to wildlife, 1080 is approved only in select regions and must be applied under strict containment protocols.
Additional agents include:
- Bromethalin – uncouples mitochondrial oxidative phosphorylation; lethal dose approximately 10 mg/kg; used in bait at 0.025 %–0.05 %.
- Diphenadione – second‑generation anticoagulant with prolonged activity; applied at 0.025 %–0.05 % in block baits.
- Aluminum phosphide – generates phosphine upon moisture exposure; employed mainly in grain storage; dosage 0.5 %–1 % in treated grain.
Safety measures mandate personal protective equipment, secure storage, and exclusion of non‑target animals. Disposal of unused bait follows hazardous‑waste guidelines. Monitoring for resistance, especially to anticoagulants, informs rotation of active ingredients to sustain efficacy.