Medications

Products used to kill scabies mites are called scabicides. No “over-the-counter” (non-prescription) products have been tested and approved to treat human scabies.

The following medications for the treatment of scabies are available only by prescription.

Classic scabies: one or more of the following may be used

1. Permethrin cream 5% Brand name product: Elimite* Permethrin is approved by the US Food and Drug Administration (FDA) for the treatment of scabies in persons who are at least 2 months of age. Permethrin is a synthetic pyrethroid similar to naturally occurring pyrethrins which are extracts from the chrysanthemum flower. Permethrin is safe and effective when used as directed. Permethrin kills the scabies mite and eggs. Permethrin is the drug of choice for the treatment of scabies. Two (or more) applications, each about a week apart, may be necessary to eliminate all mites. Children aged 2 months or older can be treated with permethrin.
2. Crotamiton lotion 10% and Crotamiton cream 10% Brand name products: Eurax*; Crotan* Crotamiton is approved by the US Food and Drug Administration (FDA) for the treatment of scabies in adults; it is considered safe when used as directed. Crotamiton is not FDA-approved for use in children. Frequent treatment failure has been reported with crotamiton.
3. Sulfur (5%-10%) ointment (multiple brand names) Sulfur in an ointment base (petrolatum) is safe for topical use in children, including infants under 2 months of age. The odor and cosmetic quality may make it unpleasant to use (CITE KARTHIKEYAN 2007).
4. Lindane lotion 1% Brand name products: None available Lindane is an organochloride. Although FDA-approved for the treatment of scabies, lindane is not recommended as a first-line therapy. Overuse, misuse, or accidentally swallowing lindane can be toxic to the brain and other parts of the nervous system; its use should be restricted to patients who have failed treatment with or cannot tolerate other medications that pose less risk. Lindane should not be used to treat premature infants, persons with a seizure disorder, women who are pregnant or breast-feeding, persons who have very irritated skin or sores where the lindane will be applied, infants, children, the elderly, and persons who weigh less than 110 pounds.
5. Ivermectin Brand name product: Stromectol* Ivermectin is an oral antiparasitic agent approved for the treatment of worm infestations. Evidence suggests that oral ivermectin may be a safe and effective treatment for scabies; however, ivermectin is not FDA-approved for this use. Oral ivermectin should be considered for patients who have failed treatment with or who cannot tolerate FDA-approved topical medications for the treatment of scabies. If used for classic scabies, two doses of oral ivermectin (200µg/kg/dose) should be taken with food, each approximately one week apart. The safety of ivermectin in children weighing less than 15 kg and in pregnant women has not been established.
   Note that although ivermectin guidelines recommend taking on an empty stomach, scabies experts recommend taking with a meal to increase bioavailability (CITE NEJM Currie article).

Crusted scabies: both oral and topical agents should be used

1. Ivermectin Brand name product: Stromectol* Ivermectin is an oral antiparasitic agent approved for the treatment of worm infestations. Evidence suggests that oral ivermectin may be a safe and effective treatment for scabies; however, ivermectin is not FDA-approved for this use. The safety of ivermectin in children weighing less than 15 kg and in pregnant women has not been established.
   For crusted scabies, ivermectin should be administered together with a topical agent. Oral ivermectin (200µg/kg/dose) should be taken with food. Depending on infection severity, ivermectin should be taken in three doses (approximately days 1, 2, and 8), five doses (approximately days 1, 2, 8, 9, and 15), or seven doses (approximately days 1, 2, 8, 9, 15, 22, and 29).
2. Permethrin cream 5% Brand name product: Elimite Permethrin is approved by the US Food and Drug Administration (FDA) for the treatment of scabies in persons who are at least 2 months of age. Permethrin is a synthetic pyrethroid similar to naturally occurring pyrethrins which are extracts from the chrysanthemum flower. Permethrin is safe and effective when used as directed. Permethrin kills the scabies mite and eggs. Permethrin is the drug of choice for the treatment of scabies. Topical permethrin should be administered every 2-3 days for 1-2 weeks to treat crusted scabies.
3. Benzyl benzoate 25% (with or without tea tree oil) Benzyl benzoate may be used as an alternative topical agent to permethrin. However, this agent may cause immediate skin irritation. Lower concentrations may be used in children (10% or 12.5%).
4. Keratolytic cream A topical keratolytic cream may also be used to help reduce the crusting of the skin and aid in the absorption of the topical permethrin or benzyl benzoate.

References:

Currie B, McCarthy J. Permethrin and ivermectin for scabies. N Engl J Med 2010; 362:717–725. Karthikeyan, K. Scabies in children. Arch Dis Child Educ Pract Ed 2007;92:ep65-ep69 doi:10.1136/adc.2005.073825

Pasay C, Mounsey K, Stevenson G, et al. Acaricidal activity of eugenol based compounds against scabies mites. PLoS One 2010; 5:e12079.

Strong M, Johnstone PW. Interventions for treating scabies (update). Cochrane Database Syst Rev 2010:CD000320.

Sharma R, Singal A. Topical permethrin and oral ivermectin in the management of scabies: A prospective, randomized, double blind, controlled study. Indian J Dermatol Venereol Leprol 2011; 77:581–586.

Currie B, Davis J. Crusted (Norwegian) Scabies Grading Scale and Treatment Planpdf icon. Department of Health and Families. Northern Territory Government. 2012.