Lice and Scabies

Question 1

Permethrin cream 5%

Answer 1

Lice and Scabies
INDICATIONS
Scabies
• Kills scabies mite and eggs.
• Drug of choice for the treatment of scabies.
• Synthetic pyrethroid similar to naturally occurring pyrethrins which are extracts from the *chrysanthemum flower.

Question 2

Ivermectin

Answer 2

Lice and Scabies
INDICATIONS
Scabies
• 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.
• Effective in the treatment of *crusted scabies (Norwegian)
- usually taken PLUS PERMETHRIN

Question 3

Permethrin lotion1%

Answer 3

Lice and Scabies
INDICATIONS
Lice
• Permethrin = synthetic pyrethroid similar to naturally occurring pyrethrins.
o Permethrin lotion 1% is approved by FDA for the treatment of head lice.
o Kills live lice but *not unhatched eggs. Permethrin may continue to kill newly hatched lice for several days after treatment. A *second treatment often is necessary on *DAY 9 to kill any newly hatched lice before they can produce new eggs.
o Approved for use on children 2+ mo
Treatment Days
o 1) Day 0 + Day 7 + Days 13-15
o 2) Day 0 + Day 9

Question 4

Spinosad

Answer 4

Lice and Scabies
INDICATIONS
Lice
Ovicidal treatment 
• Use of a nit-comb is *not essential, but it is recommended in patients being treated with spinosad to remove dead lice and nits.

Question 5

Pyrethrins + piperonyl butoxide

Answer 5

Lice and Scabies
INDICATIONS
Lice
• Pyrethrins = naturally occurring pyrethroid extracts from *chrysanthemum flower.
o Can only kill live lice, *not unhatched eggs (nits). A *second treatment is recommended on *DAY 9 to kill any newly hatched lice before they can produce new eggs.
o Should not be used by persons who are *allergic to chrysanthemums or ragweed.
o Approved for use on children 2+ yo
- concern for pyrethroid resistance
MOA
- works synergistically w/ pyrethrins by inhibiting microsomal enzymes in the louse, preventing pyrethrin catabolism, thereby extending their action

Question 6

Lindane shampoo 1%

Answer 6

Lice and Scabies
INDICATIONS
Lice
• Lindane = organochloride
• American Academy of Pediatrics (AAP) *no longer recommends it as a pediculocide. 
ADE
• Significant percut absorption
• CNS effects including seizures