Permethrin
Generic Details
Generic Name
Permethrin
Other Names
- Nix
- Elimite
- Acticin
- Lyclear
Drug Class
- Pyrethroid Insecticide
Chemical Formula
C21H20Cl2O3
Molecular Weight
391.29 g/mol
Mechanism of Action
- Acts on the nerve cell membrane to disrupt the sodium channel current
Indications
- Treatment of scabies
- Treatment of head lice infestations
Common Dosage Forms
- Topical cream
- Topical lotion
Typical Dosage
- Apply a thin layer to the affected skin and wash off after 8-14 hours for scabies
- Apply to dry hair and scalp for head lice and leave on for 10 minutes before rinsing
Pediatric Dosage
- Dosage may vary based on weight and age. Consult a healthcare provider.
Geriatric Dosage
- Dosage adjustment may be necessary. Consult a healthcare provider.
Side Effects
- Mild burning or stinging
- Itching
- Redness or swelling of the skin
Contraindications
- Hypersensitivity to permethrin or other synthetic pyrethroids
Pregnancy Category
- Category B - Animal studies have shown no risk, but human studies are inadequate
Lactation Safety
- Considered safe to use while breastfeeding when used topically according to instructions
Drug Interactions
- No significant drug interactions reported
Overdose Symptoms
- Dizziness
- Nausea
- Tingling or numbness
Antidote for Overdose
- No specific antidote. Supportive care is recommended.
Storage Conditions
- Store at room temperature away from moisture and heat.
Pharmacokinetics
- Absorption: Minimal systemic absorption after topical application
- Distribution: Not well understood
- Metabolism: Primarily hepatic
- Excretion: Mainly through feces
Precautions
- Avoid contact with eyes
- Avoid use in infants younger than 2 months without medical supervision
Warnings
- For external use only
- Do not ingest