Generic
Permethrin 5% Topical
47 brands available in the market
At a glance
Permethrin 5% Topical is an antiparasitic medication used for the treatment of scabies and crab lice infestations (Pediculosis). It causes paralysis and death of the pests by inhibiting sodium ion influx through nerve cell membrane channels.
Description
Permethrin is a pyrethroid that 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 and paralysis of the pests are the consequences of this disturbance. Less than 0.5% is absorbed over 48 hours and it is rapidly metabolized in the liver and excreted in urine.
Indications
- Scabies
- Pediculosis (crab lice infestations)
Therapeutic class
Parasiticidal preparations
Pharmacological class
Topical Scabicidal (Pyrethroid)
Pharmacology
Permethrin is a pyrethroid that disrupts sodium channel current on the nerve cell membrane, causing delayed repolarization and paralysis of the parasite. It is minimally absorbed through the skin (<0.5% over 48 hours) and rapidly metabolized in the liver, excreted primarily in urine.
Mechanism of action
Causes parasite paralysis and death by disrupting sodium channels on nerve cell membranes.
Dosage
Adult Dose (Topical):
- Scabies (30 gm tube): Full tube; apply to skin surfaces from neck to toes; wash off after 8-14 hours; may reapply in 7 days
- Pediculosis: Apply to washed hair and leave on for 10 minutes before rinsing with water; may reapply in 7 days
Pediatric Dose (Topical):
- >12 years: Full tube
- 6-12 years: Up to ½ tube
- 1-5 years: Up to ¼ tube
- 2 months-1 year: Up to ⅛ tube
- Less than 2 months: Dose not established
Administration
- For external use only
- Skin should be clean, cool, and dry before application; do not have a hot shower or bath before applying
- Apply cream to the whole body from the neck down, rubbing lightly into the skin until the cream disappears
- Babies under 2 years: Apply to face, neck, ears, and scalp as well, avoiding area around eyes and mouth
- Leave cream on for at least 8 hours (maximum 14 hours) before washing off
- If necessary, reapply after 7 days
Missed dose
If you miss a dose, consult your doctor.
Side effects
Common Side Effects:
- Skin burning
- Stinging or tingling sensation
- Erythema
- Edema
- Eczema
- Rash
- Pruritus
Precautions & warnings
- Scabies infestation is often accompanied by pruritus, edema, and erythema; treatment may temporarily exacerbate these conditions
- Avoid contact with eyes; if the cream gets in the eyes, flush with water immediately
- If the condition persists after 14 days of treatment, the doctor may suggest another treatment
- Use in pregnancy only under medical advice
Contraindications
- Known hypersensitivity to any component of pyrethroids or permethrin
Drug interactions
- Corticosteroids: Should be withheld prior to permethrin treatment (risk of exacerbating scabies infestation by reducing immune response to the mite)
Food interactions
Not food-related (topical use).
Use in pregnancy
Use in Pregnancy: Generally considered safe during pregnancy; animal studies have shown low or no adverse effects; limited human studies available.
Pregnancy Category: B — always consult a doctor before taking during pregnancy.
Use in lactation
Use in Lactation: Probably safe during breastfeeding; limited human data suggests no significant risk to the baby.
Pediatric use
Dose not established in children under 2 months.
Geriatric use
Caution required in elderly patients; consult your doctor.
Renal / hepatic impairment
Caution required in kidney and liver disease; consult your doctor.
Overdose effects
No overdose information available; consult your doctor if overused.
Storage conditions
Store in a cool, dry place, away from light; keep out of reach of children.
Chemical structure
Permethrin 5% Topical