Malathion

Malathion Brand Name– Ovide

What is Malathion

Malathion is an organophosphate insecticide used in dermatologic preparations worldwide for the treatment of ectoparasites, including Pediculus humanus capitis (human lice infestations of the hair and scalp).

Malathion is noted for its use as an aerial insecticide in heavily populated areas to control pests that are damaging to horticulture and to dilute mosquitoe populations.

Malathion is widely used in this manner due to relative safety to human, mammal, and bird populations versus other organophosphates or DDT. In medical use for the treatment of head lice, malathion exerts a rapid pediculocidal and niticidal action.

This is in contrast to other pediculocides, like pyrethrum and permethrin, which kill hatched lice, but have limited activity against lice ova (nits).

There is no evidence that malathion is clinically more effective than commonly available over-the-counter lice remedies; permethrin is often the preferred pediculocide due to its safety record and a >= 90% cure rate when proper use and nit-removal methods are employed. Malathion may be helpful in lice infestation resistant to permethrin or pyrethrins.

Resistance to malathion is rare but has been documented in Tasmania and the United Kingdom.

Malathion lotion (Ovide®) was originally approved by the FDA for the treatment of Pediculosis capitis in 1989. It was removed from the market (because of problems related to prolonged application time, flammability, and odor) and then re-introduced in 1999.

Malathion has been available in other countries for several years under various brand names, including Prioderm®, Derbac®, and Suleo-M®. Prioderm® is no longer available in Canada.

Indications

  • pediculosis
  • Pediculus capitis

Side Effects

  1. bronchospasm
  2. conjunctivitis
  3. contact dermatitis
  4. dyspnea
  5. lacrimation
  6. ocular irritation
  7. rash
  8. rhinorrhea
  9. skin irritation
  10. wheezing

Monitoring Parameters

  • laboratory monitoring not necessary

Contraindications

  • accidental exposure
  • asthma
  • breast-feeding
  • children
  • infants
  • neonates
  • ocular exposure
  • pregnancy
  • tobacco smoking

Interactions

There are no drug interactions associated with Malathion products.