Products
Malathion was commercially available as Cream Shampoo (Prioderm, 10 mg/g). It was approved in many countries in 1978. It was discontinued from sale on September 1, 2019. The drug was stored in a refrigerator.
Structure and properties
Malathion (C10H19O6PS2, Mr = 330.4 g/mol) is a racemate and belongs to the group of organic phosphoric acid esters (organophosphates). It exists as a clear, colorless to slightly yellowish liquid that is difficult to mix with water. It solidifies at about 3°C. Malathion can be translated as “bad sulfur.”
Effects
Malathion (ATC P03AX03) has insecticidal properties and kills aphids, eggs, and mites. It is a cholinesterase inhibitor and causes irreversible inhibition of insect acetylcholinesterase. It is metabolized in the louse to the active inhibitor malaoxon.
Indications
For the treatment of infestation with head lice or pubic lice.
Application
According to the package insert.
Contraindications
- Hypersensitivity
- In the United States, malathion is contraindicated in infants and young children.
- Contact with the eyes should be avoided. If the drug accidentally gets into the eyes, it should be rinsed immediately with water.
- Let hair air dry, do not use a hair dryer or any other heat source.
Full precautions can be found in the drug label.
Interactions
Interactions with other insecticides have been described.
Adverse effects
Occasional adverse effects include contact dermatitis, skin and eye irritation, and hair loss.
