Anti-parasitic Drugs

Natural extract of chrysanthemum; neurotoxic to lice (not ovicidal)

Contraindicated (CI) if allergy to chrysanthemums

Synthetic pyrethrin; disables nerve cell Na⁺ transport channels in parasites → resulting in paralysis

Pediculicidal and ovicidal

2 strengths: 1% (OTC), 5% (Rx)

CI: allergy to chrysanthemums

Chlorinated hydrocarbon; blocks neural transmission by interfering with GABA → respiratory/muscular paralysis in parasites

Used for scabies, pubic lice, head lice, and body lice

SE: ICD, CNS symptoms (i.e., seizures)

Organophosphate cholinesterase inhibitor

Flammable; used in scabies, head lice

Blocks glutamate-gated chloride channels → paralysis of parasite

Used for strongyloidiasis, onchocerciasis, Norwegian scabies

Scabicide; unknown mechanism

SE: contact dermatitis

Precipitated sulfur (6%)

Unclear mechanism of action

Treatment for scabies in pregnant women and infants < 2 years of age

Inhibits fumarate reductase
(helminth-specific enzyme)

Used in cutaneous larva migrans
SE: dizziness, drowsiness, jaundice

Pentavalent antimonial; unclear mechanism

Treatment for leishmaniasis
SE: pancreatitis, hepatitis, renal failure, prolong QT interval

Inhibits protozoal DNA/RNA/phosopholipid/ protein synthesis

Used for trypanosomiasis and leishmaniasis

Diethylcarbamazine
(DEC)

Piperazine derivative, unknown mechanism

{Mazzotti reaction patient with onchocerciasis treated with DEC → fever, hypotension, tachycardia}

Used for filariasis, onchocerciasis