PYRETHRINS

Availability

0.18%, 0.2%, 0.3% liquid; 0.3% gel; 0.3% shampoo

Action

Pediculicide solution that contains active chemicals in deodorized kerosene. Acts as a contact poison affecting the parasite's nervous system, causing paralysis and death.

Therapeutic Effect

Controls head lice, pubic (crab) lice, and body lice and their eggs (nits).

Uses

External treatment of Pediculus humanus infestations.

Contraindications

Sensitivity to solution components; skin infections and abrasions; pregnancy (category C), lactation.

Cautious Use

Ragweed-sensitized patient, infants, children.

Route & Dosage

Administration

• Apply enough solution to completely wet infested area, including hair. Allow to remain on area for 10 min.
• Wash and rinse with large amounts of warm water.
• Use fine-toothed comb to remove lice and eggs from hair.
• Shampoo hair to restore body and luster.
• Repeat treatment once in 24 h if necessary.
• Repeat treatment in 7–10 d to kill newly hatched lice.
• Do not apply to eyebrows or eyelashes without consulting physician.
• Flush eyes with copious amounts of warm water if accidental contact occurs.

Adverse Effects (≥1%)

Nursing Implications

Patient & Family Education

• Do not swallow, inhale, or allow pyrethrins to contact mucosal surfaces or the eyes.
• Discontinue use and consult physician if treated area becomes irritated.
• Examine each family member carefully; if infested, treat immediately to prevent spread or reinfestation of previously treated patient.
• Dry clean, boil, or otherwise treat contaminated clothing. Sterilize (soak in pyrethrins) comb and brushes used by patient.
• Do not share combs, brushes, or other headgear with another person.

Common adverse effects in italic, life-threatening effects underlined; generic names in bold; classifications in SMALL CAPS; Canadian drug name; Prototype drug