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Pronunciation
(per METH rin)
U.S. Brand Names
Generic Available
Yes: Excludes spray
Canadian Brand Names
Pharmacologic Category
Pharmacologic Category Synonyms
Use: Labeled Indications
Single-application treatment of infestation with Pediculus humanus capitis (head louse) and its nits or Sarcoptes scabiei (scabies); indicated for prophylactic use during epidemics of lice
Pregnancy Risk Factor
B
Lactation
Effect on infant unknown
Contraindications
Hypersensitivity to pyrethyroid, pyrethrin, chrysanthemums, or any component of the formulation; lotion is contraindicated for use in infants <2 months of age
Warnings/Precautions
Concerns related to adverse effects:
• Skin irritation: Treatment may temporarily exacerbate the symptoms of itching, redness, and swelling.
Special populations:
• Pregnancy: Use during pregnancy only if clearly needed.
Other warnings/precautions:
• Appropriate use: For external use only.
Adverse Reactions
1% to 10%:
Dermatologic: Pruritus, erythema, rash of the scalp
Local: Burning, stinging, tingling, numbness or scalp discomfort, edema
Drug Interactions
There are no known significant interactions.
Mechanism of Action
Inhibits sodium ion influx through nerve cell membrane channels in parasites resulting in delayed repolarization and thus paralysis and death of the pest
Pharmacodynamics/Kinetics
Absorption: <2%
Metabolism: Hepatic via ester hydrolysis to inactive metabolites
Excretion: Urine
Dosage
Topical:
Head lice: Children >2 months and Adults: After hair has been washed with shampoo, rinsed with water, and towel dried, apply a sufficient volume of topical liquid (lotion or cream rinse) to saturate the hair and scalp. Leave on hair for 10 minutes before rinsing off with water; remove remaining nits; may repeat in 1 week if lice or nits still present.
Scabies: Apply cream from head to toe; leave on for 8-14 hours before washing off with water; for infants, also apply on the hairline, neck, scalp, temple, and forehead; may reapply in 1 week if live mites appear
Permethrin 5% cream was shown to be safe and effective when applied to an infant <1 month of age with neonatal scabies; time of application was limited to 6 hours before rinsing with soap and water
Administration: Topical
Avoid contact with eyes and mucous membranes during application. Because scabies and lice are so contagious, use caution to avoid spreading or infecting oneself; wear gloves when applying
Cream rinse/lotion: Shake cream rinse well before using. Apply immediately after hair is shampooed, rinsed, and towel-dried. Apply enough to saturate hair and scalp (especially behind ears and on nape of neck). Leave on hair for 10 minutes before rinsing with water. Remove nits with fine-tooth comb. May repeat in 1 week if lice or nits are still present.
Cream: Apply from neck to toes. Bathe to remove drug after 8-14 hours. Repeat in 7 days if lice or nits are still present. Report if condition persists or infection occurs.
Patient Education
For external use only. Do not apply to face and avoid contact with eyes or mucous membrane. Clothing and bedding must be washed in hot water or dry cleaned to kill nits. May need to treat all members of household and all sexual contacts concurrently. Wash all combs and brushes with permethrin and thoroughly rinse. Breast-feeding precaution: Consult prescriber if breast-feeding.
Cream rinse/lotion: Apply immediately after hair is shampooed, rinsed, and towel-dried. Apply enough to saturate hair and scalp (especially behind ears and on nape of neck). Leave on hair for 10 minutes before rinsing with water. Remove nits with fine-tooth comb. May repeat in 1 week if lice or nits are still present.
Cream: Apply from neck to toes. Bathe to remove drug after 8-14 hours. Repeat in 7 days if lice or nits are still present. Report if condition persists or infection occurs.
Geriatric Considerations
Because of its minimal absorption, permethrin is a drug of choice and is preferred over lindane.
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
Nursing: Physical Assessment/Monitoring
Assess head, hair, and skin surfaces for presence of lice and nits. Assess knowledge/teach patient appropriate application and use and adverse symptoms to report.
Dosage Forms
Excipient information presented when available (limited, particularly for generics); consult specific product labeling.
Cream, topical (Acticin®, Elimite®): 5% (60 g) [contains coconut oil]
Lotion, topical: 1% (59 mL)
Liquid, topical [creme rinse formulation] (Nix®): 1% (60 mL) [contains isopropyl alcohol 20%]
Solution, spray [for bedding and furniture]:
A200® Lice: 0.5% (180 mL)
Nix®: 0.25% (148 mL)
Rid®: 0.5% (150 mL)
Pricing: U.S. (www.drugstore.com)
Cream (Acticin)
5% (60): $18.99
Cream (Elimite)
5% (60): $72.71
Lotion (Permethrin)
1% (59): $16.99
References
Dorman DC and Beasley VR, “Neurotoxicology of Pyrethrin and the Pyrethroid Insecticides,” Vet Hum Toxicol, 1991, 33(3):238-43.
“Drugs for Head Lice,” Med Lett Drugs Ther, 1997, 39(992):6-7.
“Drugs for Parasitic Infections,” Med Lett Drugs Ther, 1998, 40(1017):1-12.
He F, Wang S, Liu L, et al, “Clinical Manifestations and Diagnosis of Acute Pyrethroid Poisoning,” Arch Toxicol, 1989, 63(1):54-8.
Hogan DJ, Schachner L, Tanglertsampan C, “Diagnosis and Treatment of Childhood Scabies and Pediculosis,” Pediatr Clin North Am, 1991, 38(4):941-57.
Krowchuk DP, Tunnessen WW Jr, and Hurwitz S, “Pediatric Dermatology Update,” Pediatrics, 1992, 90(2 Pt 1):259-64.
Liu LX and Weller PF, “Antiparasitic Drugs,” N Engl J Med, 1996, 334(18):1178-84.
Quarterman MJ and Lesher JL, “Neonatal Scabies Treated With Permethrin 5% Cream,” Pediatr Dermatol, 1994, 11(3):264-6.
International Brand Names
Lexi-Comp.com
Last full review/revision April 2009
Content last modified April 2009
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