Skip to Content


Pronunciation: mal-ah-THIGH-ahn
Class: Pediculicide

Trade Names

- Lotion 0.5%


Inhibits cholinesterase activity.

Slideshow: Fighting the Fight: Fibromylagia Explained

Indications and Usage

Treatment of head lice ( Pediculus humanus capitis ) and their ova of the scalp hair.


Neonates and infants; hypersensitivity to any component of the product.

Dosage and Administration

Adults and Children 6 yr of age and older

Topical Apply lotion on dry hair in amount just sufficient to thoroughly wet the hair and scalp, paying particular attention to back of head and neck. Wash hands after application. Allow hair to dry normally, without use of electric heat source, and allow hair to remain uncovered. Shampoo hair after 8 to 12 h. Rinse and use a fine-toothed (nit) comb to remove dead lice and eggs. If lice are still present after 7 to 9 days, repeat with a second application.


Store lotion at controlled room temperature (68° to 77°F). Keep bottle tightly capped and away from heat and open flame.

Drug Interactions

None well documented.

Laboratory Test Interactions

None well documented.

Adverse Reactions


Irritation to skin and scalp.


Conjunctivitis caused by accidental contact with eyes.



Category B .


Undetermined; however, malathion is absorbed through the skin.


Safety and efficacy not established in children younger than 6 yr of age.

External use

Avoid contact with eyes; if accidentally placed in eye, flush immediately with water.


Because product contains alcohol, it should not be exposed to open flame or electric heat, including hair dryers and electric curlers; do not smoke while applying lotion or while hair is wet.



Severe respiratory distress.

Patient Information

  • Caution patient or caregiver that medication has potential for causing serious harm and not to exceed prescribed dose or apply more frequently than prescribed by health care provider. Advise patient or caregiver to not reapply unless specifically advised by health care provider.
  • Caution patient or caregiver to avoid contact with eyes and that if accidental eye contact occurs to immediately flush the eyes with water to remove medication. Advise patient or caregiver to notify health care provider if eye irritation or sensitivity follows exposure to the eyes.
  • Caution patient or caregiver that medication may be toxic if swallowed and to seek medical care immediately in case of accidental ingestion.
  • Teach patient or caregiver proper technique for applying lotion: apply lotion on dry hair in amount just sufficient to thoroughly wet hair and scalp; wash hands after applying lotion; allow hair to dry naturally; after 8 to 12 h (eg, overnight) shampoo hair; rinse and use fine-toothed (nit) comb to remove dead lice and eggs.
  • Caution patient or caregiver that lotion is flammable and not to smoke while applying lotion or expose treated hair to open flames or electric heat sources (eg, hair dryer, electric curler) until hair is dry.
  • Advise patient or caregiver that slight stinging sensations may be noted following application but that this is expected and should not be bothersome.
  • Advise patient or caregiver that if skin irritation occurs to wash scalp and hair immediately. If irritation clears, lotion may be reapplied. If irritation reoccurs, wash scalp and hair again and notify health care provider.

Copyright © 2009 Wolters Kluwer Health.

More about malathion topical

Consumer resources

Professional resources

Related treatment guides