Permethrin

Indications

Permethrin cream is indicated for the treatment of scabies and crab lice infestations (Pediculosis). Scabies can affect everyone in the family. If one is infected, all family members must be treated together.

Pharmacology

Permethrin cream contains Permethrin, a pyrethroid, which is a topical scabicidal agent for the treatment of infestation with Sarcoptes Scabiei (scabies). It acts on the nerve cell membrane to disrupt the sodium channel current by which the polarization of the membrane is regulated. Delayed repolarization & paralysis of the pests are the consequences of this disturbance.

Pharmacokinetics: The only approved route of administration is the topical route and there are few human data available on systemic exposure or kinetics following permethrin application to the skin. Some presystemic metabolism occurs in skin. Less than 0.5% of applied permethrin is absorbed during the first 48 hours. Absorbed permethrin is rapidly metabolized by ester hydrolysis, most likely in the liver and the products are excreted primarily in the urine.

Dosage And Administration

Recommended duration of Treatment:

  • Adults and children over 12 years: a full tube
  • Children aged 6-12 years: up to 1⁄2 of a tube
  • Children aged 1-5 years: up to  ¼ of a tube
  • Children aged 2 months to 1 year: up to ⅛ of a tube
  • Children Less then 2 month: dose is not established

 

Administration

Before application of Permethrin cream the skin should be clean, cool and dry. Do not have a hot shower or bath before applying.

For adults and children over 2 years: Apply the cream to the whole body from the neck down, rubbing lightly into the skin until the cream disappears. It is important to include all skin surfaces, such as between the fingers and toes, under the nails and on the soles of the feet.

For babies under 2 years: Apply to the face, neck, ears and scalp as well, only avoiding the area immediately around the eyes and mouth.

Leave cream on for at least 8 hours, before washing off. Reapply to any area that may be washed during the 8h treatment time (such as after washing the hands). If necessary, permethrin cream should be used again after 7 days as per the advice of the doctor.

Interaction

The treatment of eczemodous like reactions with corticosteroids should be withheld prior to treatment with permethrin, as there is a risk of exacerbating the scabies infestation by reducing the immune response to the mite.

Contraindications

Permethrin is contraindicated in patients with known hypersensitivity to any component of pyrethroids or permethrin. Nursing staff who routinely apply permethrin may wear globes to avoid any possible irritation to the hands.

Side Effects

In Scabies patients, skin discomfort, usually described as burning, stinging or tingling occurs in a few individuals soon after the cream is applied. Others transient signs and symptoms of irritation including enythema, edema, eczema, rash and puritis.

Pregnancy And Lactation

In the absence of specific studies in pregnant women, its use in pregnancy should only follow medical advice. It is not known whether permethrin is excreted in human milk so it should not be used in nursing mothers.

Precautions And Warnings

Scabies infestation is often accompanied by pruritus, edema & erythema. Treatment with permethrin may temporarily exacerbate these conditions. Patients should be advised to avoid contact with eyes during application & to flash with water immediately if the cream gets in the eyes.

Therapeutic Class

Parasiticidal preparations.

Storage Conditions

Store in a cool, dry place, away from light & keep out of the reach of children...

Available Brand Names