Cypermethrin-d5

Cypermethrin-d₅ is intended for use as an internal standard for the quantification of cypermethrin by GC- or LC-MS. Cypermethrin is a type II pyrethroid insecticide.^1,2,3,4 It prolongs opening of sodium channels resulting in membrane depolarization and a conductance block of the insect nervous system, and point mutations in sodium channels induce cypermethrin-resistance in house flies, cockroaches, and mosquitos.³ Cypermethrin (1-1.5 mg) reduces survival of ticks (H. anatolicum) in vitro in a concentration-dependent manner.² Topical administration of cypermethrin reduces the number of ticks on infested cattle. Cypermethrin (5 and 10 ppm) reduces survival of lice (D. ovis) in sheep fleece and prevents re-infestation in contact-challenged sheep for 7 and 19 weeks, respectively.¹ It induces developmental neurotoxicities in zebrafish, increasing mortality and edema and inducing body-axis curvature when used at concentrations ranging from 50 to 200 μg/L.⁵ Cypermethrin (15 mg/kg twice weekly for 24 weeks) also induces Parkinson's disease-like neurodegeneration in rats, decreasing locomotor activity, dopamine production, and the number of tyrosine droxylase positive (TH⁺) neurons in the substantia nigra.⁴ Formulations containing cypermethrin have been used in the control of insects in agriculture and on commercial and residential premises.