WHO Acute Hazard classification: Not listed

Mechanism of Action of Dicyclanil

The mechanism of action of dicyclanil has not been elucidated. It is certainly not a Chitin Synthesis Inhibitor like other insect growth regulators such as the benzoylureas. It seems to acts upon the molting process in a similar way as cyromazine, probably interfering with the process of chitin deposition.

Toxicity and Tolerance of Dicyclanil

• LD50 acute, rats, p.o. 520 mg/kg
• LD50 acute, rats, dermal, > 2000 mg/kg
• Sheep tolerate topically applied dicyclanil very well. At 3x the recommended dose o 42 mg/kg no toxic symptoms were recorded. At 10x the recommended dose no external symptoms were observed, but significant weight increases in liver and spleen were recorded.

Toxic Symptoms caused by Dicyclanil Poisoning

• In toxicity studies in rats the following symptoms were observed after heavy oral overdosing: piloerection (bristling of hairs), hunched posture and dyspnea (difficult breathing), ataxia (uncoordinated movements), reduced activity.
• In toxicity studies in dogs several symptoms were observed after heavy oral overdosing: tremor, vomit, dyspnea, slight apathy and ataxia (uncoordinated movements), weight loss, reduced food consumption, unusula raised tails and frequent shaking.

Dicyclanil Side Effects, Adverse Drug Reactions (ADRs) and Warnings

• As a general rule, ADRs following topical administration of dicyclanil at the recommended dose are very rare due to its low toxicity, the high safety margin and the excellent tolerance of sheep and goats.

Antidote and Treatment of Dicyclanil Intoxication

• There is no antidote for dicyclanil poisoning.
  
• Treatment consists in supportive and symptomatic measures.

Pharmacokinetics of Dicyclanil

• Topically administered dicyclanil is poorly absorbed through the skin of sheep (2% to 4%). The absorbed dicyclanil is partly metabolized and excreted through both urine (mainly metabolites) and feces (mainly unchanged dicyclanil).
• About 95% of the administered dose is excreted in the 7 days following treatment.

Environmental Toxicity of Dicyclanil

• Dicyclanil is slightly toxic to fish and moderately toxic to birds.
• Dicyclanil is highly toxic to Diptera and Siphonaptera, but only slightly hazardous for other arthropods.
• Dicyclanil is poorly photodegradable in aqueous environment, but it degrades rapidly (half-life ~20 days) in moist soil under aerobic conditions.
• Dicyclanil does not accumulate in soil or in the chain food.
• Correct use on sheep dicyclanil is unlikely to be directly detrimental for the environment.
• In Australia, it was concluded that dicyclanil scour residues from the wool industry were unlikely to be harmful for the environment.

Additional Information

Click here for a list and overview of all safety summaries of antiparasitic active ingredients in this site.

• Dicyclanil is an insect growth regulators (IGR) that belongs to the chemical class of the cyano-pyrimidines.
• Dicyclanil is not used in dogs or cats.
• Dicyclanil is not used in human medicines.
• Dicyclanil is not used in crop pesticides.
• Dicyclanil is not used in biocides for public or domestic hygiene.
• Click here for General safety of antiparasitics for domestic animals.
• Click here for General safety of antiparasitics for humans.
• Click here for General safety of antiparasitics for the environment.
• Click here for technical and commercial information on dicyclanil.