Transcript Treatment of Scabies: Permethrin vs. Ivermectin

Treatment of Scabies:
Permethrin vs. Ivermectin
A04
義大醫院
王柏欣, 陳奕峰, 詹子慶
Transmission of scabies
Mite Sarcoptes scabiei, skin to skin contact
 Typical vs atypical/crusted/keratotic
 2-6 weeks before symptoms are apparent
 During the incubation period the newly infested
healthcare worker could be a source of
transmission
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Prevention and Control
Recognize patient with symptoms and signs
 Skin scrapings
 Contact isolation precautions
 Personal protective equipment
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Pharmaceutical agents :
 Lindane: standard tx, but resistance
 Permethrin vs Ivermectin
Thinking Process
Inadequate treatment of scabies increase transmission of scabies
throughout hospitals
Find a more effective treatment among choices of medication
Permethrin vs Ivermectin
Search form evidence-based medicine database for answer
Ask an answerable question
Permethrin vs Ivermectin
Which is better for scabies
treatment?
PICO
Patient
Scabies infected patient
Intervention
Medical treatment with Permethrin
Comparison
Medical treatment with Ivermectin
Outcome
Prevention of scabies outbreak
Tracking Down the Best
Evidence
Cochrane Database of Systemic Reviews
 PubMed Library
 Clin-eguide
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Tracking down the best evidence
Database: Cochrane Database of Systemic Reviews
Key Word: scabies
Result:
[Review]
Interventions for treating scabies
M Strong, PW Johnstone
Cochrane Database of Systematic Reviews 2008 Issue 2
(Status: Edited)
Tracking down the best evidence
Database: Clin-eguide
Key Word: scabies
Result:
A comparative study of oral ivermectin and topical
permethrin cream in the treatment of scabies
Journal of the American Academy of
Dermatology - Volume 42, Issue 2 (February
2000) - Copyright © 2000 American Academy of
Dermatology, Inc.
Permethrin acts by disrupting the sodium
channel current
 Topical application ensures maximum
concentration of the drug in the skin
 Infrequently used because of its high cost
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Ivermectin bind selectively to GABA gated
chloride ion channels, which occur in nerve
and muscle cells
 not be effective against the younger stages
inside the egg because the nervous system
has not yet developed
 Additional doses needed
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Single application of permethrin was superior to
a single oral dose of ivermectin by 2 weeks
(P < .001).
Tracking down the best evidence
Database: PubMed
Key Word: scabies
Result:
2001 National Guideline on the Management of Scabies
 Evidence Base
 Medline search strategy
 Years covered 1966-1997
 Key terms - scabies/th, scabies/dt, lindane/tu,
permethrin/tu, malathion/tu.
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Permethrin 5% cream (level of evidence 1b, grade of
recommendation A)
Malathion 0.5% aqueous lotion (level of evidence 4, grade of
recommendation C)
These should be applied to the whole body from the neck
downwards, and washed off after 12 hours, usually overnight.
Itch may persist for several weeks.
Application of crotamiton cream may give symptomatic relief.
Antihistamines may also be helpful in relieving itch.
Potentially contaminated clothes and bedding should be washed at
high temperature (>50°C) if possible.
Mites separated from the human host die after 72 hours.
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Oral ivermectin in a dose of 200 mcg/kg in the
treatment of Norwegian scabies.
Ivermectin is not licensed for this purpose in the UK
There have been concerns about toxicity
Pregnancy and Breastfeeding
Permethrin is safe during pregnancy or breastfeeding
Thank you for listening!!