Head lice treatment Flashcards
How long can lice survive with potential to reinfest?
55 hours
What other things/people must you be concerned about when you see a patient with head lice?
People they are in close contact with should be treated. Also, the patient’s bed linens, clothes, etc should be washed and such
Lice treatments are pediculicidal and ovicidal. What drug is both? What are the other drugs?
Malathion is both pediculicidal AND ovicidal. The rest of the head lice drugs are pediculicidal ONLY
Describe the timing of administration of the pediculicidal drugs
2 or 3 courses of treatment spaced 1 week apart
Describe the timing of administration of the pediculicidal/ovicidal drugs (malathion)
1 or 2 courses of treatment spaced 1 week apart
MOA of malathion
Lice metabolize it to malaoxon which inhibits Acetyl choline esterase –> paralysis
ADE of malathion
SLUDGEBBB Salivation Lacrimation Urination Defecation GI symptoms Emesis Bronchorrhea Bronchospasm Bradycardia
If you were to be stupid and eat malathion, how could you treat the symptoms?
Atropine and Pralidoxime
Goes without saying but administration of malathion is?
Topical.. Dont eat it!
List the head lice drugs
Malathion, Permethrin, Lindane, Ivermectin
Permethrin MOA
Binds voltage gated sodium channels on lice (not humans!) –> hyper excitability and paralysis
Permethrin ADE
Asthma exacerbation in pts allergic to ragweed
Why has efficacy waned for Permethrin?
Knock down resistance in louse sodium channels
Very very little Permethrin absorbs percutaneously into human skin. The little that does is harmless because?
It is quickly metabolized by ester hydrolysis
Lindane administration?
Shampoo
Lindane MOA
Not listed in Sweatman’s document. He just says that it is not often used, only when pts cannot tolerate or have failed first line therapy with safer medication
Lindane ADE
Seizures and death if you use if waaayyy too much. Rarely, seizures and death after one use
MOA for Lindane causing seizures in people?
Lindane is a CNS stimulant that blocks GABA action (similar to DTT)
BBW for Lindane?
Skin conditions and prematurity will increase systemic absorption.. Also, contraindicated in pts with seizure disorders
Ivermectin administration?
Oral or topical
Ivermectin MOA
Binds glutamate gated chloride ion channels in invertebrate nerve and muscle cells –> hyperexcitability and paralysis
Ivermectin ADE
- Worsens asthma
- Elevates liver enzymes
- Crosses BBB in children
Ivermectin contraindicated in what population?
Children (their BBB is not developed)