Pyrethrins and Piperonyl ButoxideU.S. Brand Names: A-200�(r) Maximum Strength [OTC]; Pronto�(r) [OTC]; Pyrinyl Plus�(r) [OTC]; RID�(r) Maximum Strength [OTC]; Tisit�(r) [OTC]; Tisit�(r) Blue Gel [OTC]
Synonyms: Piperonyl Butoxide and Pyrethrins
Generic Available: Yes: Shampoo
Canadian Brand Names: Pronto�(r) Lice Control; R & C™ II; R & C™ Shampoo/Conditioner; RID�(r) Mousse
Use: Treatment of Pediculus humanus infestations (head lice, body lice, pubic lice and their eggs)
Pregnancy Risk Factor: C
Contraindications: Hypersensitivity to pyrethrins, ragweed, chrysanthemums, or any component of the formulation
Warnings/Precautions: For external use only; do not use near the eye, in eyelashes or eyebrows. Avoid contact with mucosal tissues (nasal, oral, or genital).
Adverse Reactions: Frequency not defined. Dermatologic: Pruritus Local: Burning, stinging, irritation with repeat use
Drug Interactions: No data reported
Stability: Store at room temperature of 20°C to 25°C (68°F to 77°F); do not puncture or incinerate mousse container
Mechanism of Action: Pyrethrins are derived from flowers that belong to the chrysanthemum family. The mechanism of action on the neuronal membranes of lice is similar to that of DDT. Piperonyl butoxide is usually added to pyrethrin to enhance the product's activity by decreasing the metabolism of pyrethrins in arthropods.
Pharmacodynamics/Kinetics: Onset of action: ~30 minutes Absorption: Minimal Metabolism: Via ester hydrolysis and hydroxylation
Dosage: Application of pyrethrins: Topical products: Apply enough solution to completely wet infested area, including hair Allow to remain on area for 10 minutes Wash and rinse with large amounts of warm water. Use fine-toothed comb to remove lice and eggs from hair Shampoo hair to restore body and luster Treatment may be repeated if necessary once in a 24-hour period Repeat treatment in 7-10 days to kill newly hatched lice Note: Keep out of eyes when rinsing hair; protect eyes with a wash cloth or towel Solution for furniture, bedding: Spray on entire area to be treated; allow to dry before use. Intended for use on items which cannot be laundered or dry cleaned. Not for use on humans or animals.
Administration: For external use only; avoid touching eyes, mouth, or other mucous membranes.
Patient Education: For external use only; avoid touching eyes, mouth, or other mucous membranes; do not use in eyelashes or eyebrows; contact physician if irritation occurs or if condition does not improve in 2-3 days
Dental Health: Effects on Dental Treatment: No significant effects or complications reported
Dental Health: Vasoconstrictor/Local Anesthetic Precautions: No information available to require special precautions
Mental Health: Effects on Mental Status: None reported
Mental Health: Effects on Psychiatric Treatment: None reported
Dosage Forms: Foam, topical [mousse] (RID�(r)): Pyrethrum extract 0.33% and piperonyl butoxide 4% (156 g) Gel (Tisit�(r) Blue Gel): Pyrethrum extract 0.33% and piperonyl butoxide 3% (30 g) Liquid, topical (Tisit�(r)): Pyrethrum extract 0.33% and piperonyl butoxide 2% (60 mL, 120 mL) Shampoo: Pyrethrum extract 0.33% and piperonyl butoxide 4% (60 mL, 120 mL) A-200�(r) Maximum Strength: Pyrethrum extract 0.33% and piperonyl butoxide 4% (60 mL, 120 mL) [contains benzyl alcohol] Pronto�(r): Pyrethrum extract 0.33% and piperonyl butoxide 4% (60 mL, 120 mL) [contains benzyl alcohol; supplied with comb; also available with creme rinse or in a kit containing shampoo, creme rinse, comb, gloves and furniture spray] Pyrinyl Plus�(r): Pyrethrum extract 0.33% and piperonyl butoxide 4% (60 mL) RID�(r) Maximum Strength: Pyrethrum extract 0.33% and piperonyl butoxide 4% (60 mL, 120 mL, 240 mL) [also available in a kit containing shampoo, gel, and furniture spray] Tisit�(r): Pyrethrum extract 0.33% and piperonyl butoxide 3% (60 mL, 120 mL) [also available in a kit containing shampoo, comb, and furniture spray] Solution, spray [for furniture, garments, bedding; not for human or animal use] (Tisit�(r)): Pyrethrum extract 0.4% and piperonyl butoxide 2% (150 mL)
References: Coats JR, "Mechanisms of Toxic Action and Structure-Activity Relationships for Organochlorine and Synthetic Pyrethroids Insecticide,"Environ Health Perspect, 1990, 87:255-62. Culver CA, Malina JJ, and Talbert RL, "Probable Anaphylactoid Reaction to a Pyrethrin Pediculicide Shampoo,"Clin Pharm, 1988, 7(11):846-9. Dorman DC and Beasley VR, "Neurotoxicity of Pyrethrin and the Pyrethroid Insecticides,"Vet Hum Toxicol, 1991, 33(3):238-43. "Drugs for Parasitic Infections,"Med Lett Drugs Ther, 1998, 40(1017):1-12. Liu LX and Weller PF, "Antiparasitic Drugs,"N Engl J Med, 1996, 334(18):1178-84. Wax PM and Hoffman RS, "Fatality Associated With Inhalation of a Pyrethrin Shampoo,"J Toxicol Clin Toxicol, 1994, 32(4):457-60.
International Brand Names: Pronto�(r) Lice Control (CA); R & C™ II (CA); R & C™ Shampoo/Conditioner (CA); RID�(r) Mousse (CA)
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(pye RE thrins & pi PER oh nil byo TOKS ide)
