Generic Permethrin

Introduction

Permethrin is a synthetic pyrethroid insecticide used primarily as a topical antiparasitic agent. In Hong Kong it is employed for the treatment of scabies and head‑lice infestations, two common skin conditions that cause itching and discomfort. The product contains the active compound Permethrin and belongs to the skin‑care and antiparasitic medication groups. Beyond its antiparasitic action, permethrin can be applied to reduce the risk of secondary bacterial infection by eliminating the responsible parasites.

What is Permethrin?

Permethrin is a synthetic chemical that mimics natural pyrethrins derived from chrysanthemum flowers. It is classified as a topical antiparasitic agent and is marketed both as a generic product and under several brand names, including Nix (for pediculosis) and Elimite (for scabies).

Permethrin is the generic version of Nix and Elimite, containing the same active compound Permethrin. Our online pharmacy provides this generic alternative as a cost‑effective treatment option.

The drug is manufactured by a range of qualified pharmaceutical companies worldwide and is distributed in cream, lotion, and spray formulations. In Hong Kong, the Department of Health has approved permethrin for over‑the‑counter (OTC) use in specific concentrations for scabies (5 %) and head‑lice (1 %).

How Permethrin Works

Permethrin binds to voltage‑gated sodium channels on the neuronal membranes of insects and mites. This binding prolongs channel opening, causing persistent depolarisation of the nerve cell. The resulting hyperexcitation leads to paralysis and death of the parasite within minutes to a few hours after application.

Because human sodium channels are less sensitive to permethrin, systemic absorption through intact skin is minimal. The therapeutic effect therefore appears within 2–4 hours for scabies and within 24 hours for lice, with residual activity that prevents re‑infestation for up to 7 days. Clearance occurs primarily via hepatic metabolism and renal excretion of inactive metabolites.

Conditions Treated with Permethrin

• Scabies – a contagious infestation by Sarcoptes scabiei mite, presenting with intense nocturnal itching and characteristic burrow lesions. In Hong Kong, an estimated 1–2 % of the population experiences scabies annually, with higher rates in crowded housing. Permethrin 5 % cream eradicates the mite in >95 % of cases when applied as directed.
• Pediculosis capitis (head lice) – common among school‑age children and their families. The prevalence in Hong Kong schools is reported at 5–10 % during the school year. Permethrin 1 % lotion or spray kills lice and most nymphs, breaking the transmission cycle.

Both conditions are treated topically because permethrin acts directly on the parasites residing on the skin or hair shafts, providing rapid symptomatic relief and preventing secondary bacterial infections.

Who is Permethrin For?

• Individuals with confirmed scabies – adults or adolescents who have typical lesions or a positive microscopic examination.
• Children aged ≥2 months – the 1 % formulation is approved for infants ≥2 months, while the 5 % scabies cream is safe for children ≥6 months.
• Pregnant or breastfeeding women – topical permethrin is considered low risk; however, use should be limited to the prescribed area and under medical guidance.
• Patients who cannot tolerate oral antiparasitics – permethrin offers a non‑systemic alternative when oral ivermectin is contraindicated.

Permethrin is NOT appropriate for:

• Individuals with a known hypersensitivity to permethrin or other pyrethroids.
• Extensive skin erosions or open wounds, as absorption may increase.
• Patients with severe hepatic impairment, although data are limited, caution is advised.

Risks, Side Effects, and Interactions

Common

• Localised skin irritation (pruritus, erythema, burning) – typically resolves within 24 hours.
• Mild itching or warmth at the application site – may reflect a reaction to dying parasites.

Rare

• Contact dermatitis with vesicle formation – requires discontinuation and topical corticosteroid therapy.
• Transient photosensitivity – avoid direct sun exposure for 12 hours after application.

Serious

• Systemic allergic reaction (angio‑edema, urticaria, anaphylaxis) – extremely rare; seek emergency care if symptoms develop.
• Severe skin necrosis – reported only in cases of misuse on large areas or damaged skin.

Drug–drug interactions

• Permethrin has minimal systemic absorption; therefore, clinically significant interactions are rare.
• Caution when co‑applied with other topical agents (e.g., corticosteroids, antibacterials) that may alter skin permeability.

Practical Use: Dosing, Missed Dose, Overdose

• Scabies (5 % cream) – Apply a thin layer over the entire body from the neck down, including soles and scalp (if indicated). Leave on for 8–14 hours (overnight) then wash off. Repeat after 7 days to eliminate any newly hatched mites.
• Head lice (1 % lotion or spray) – Apply to dry hair, ensuring complete coverage of the scalp and hair shafts. Leave for 10 minutes, then rinse thoroughly. A second application after 7 days is recommended to kill any remaining nymphs.

Missed dose – If a dose is missed, apply as soon as remembered provided the recommended exposure window has not exceeded 24 hours. Do not double the dose.

Overdose – Accidental ingestion of a large amount of permethrin is unlikely to cause systemic toxicity due to poor oral absorption. Nevertheless, seek medical attention if ingestion occurs, especially in children. Induce vomiting only under professional guidance.

Practical precautions

• Do not apply to broken skin, open wounds, or mucous membranes.
• Avoid contact with eyes; wash immediately with water if exposure occurs.
• Alcohol or other volatile solvents should not be mixed with the preparation.
• No restriction on food or alcohol, as systemic exposure is negligible.

Buying Permethrin from Our Online Pharmacy

Permethrin can be purchased directly from our online pharmacy in Hong Kong. Our service offers:

• Affordable pricing – near manufacturer cost, making generic permethrin an economical alternative to brand‑name products.
• Verified quality – we source only from licensed overseas suppliers that meet international Good Manufacturing Practice (GMP) standards.
• Guaranteed delivery – discreet packaging with express shipping (≈7 days) or regular airmail (≈3 weeks).
• Online‑only access – for patients who face limited stock in local pharmacies or lack insurance coverage for OTC antiparasitics.

We operate as a pharmacy broker service, collaborating with overseas licensed pharmacies to bring authentic, high‑quality medication to Hong Kong while respecting patient privacy.

FAQ

• Is Permethrin available in both brand‑name and generic forms in Hong Kong?
  Yes. The drug is sold under brand names such as Nix and Elimite, as well as generic versions containing the same active compound. Generic permethrin is typically less expensive while offering equivalent efficacy.

• Does Permethrin require cold storage?
  No. Permethrin creams and lotions should be stored at room temperature (15–30 °C) away from direct sunlight, heat, and moisture. Refrigeration is not necessary and may affect the formulation.

• What packaging does Permethrin come in when ordered online?
  The medication is supplied in sealed, opaque tubes or bottles that protect the active ingredient from light exposure. Each package includes a patient information leaflet in English and Chinese.

• Can Permethrin be safely imported into Hong Kong for personal use?
  Personal import of OTC permethrin in quantities for self‑treatment is permitted under Hong Kong customs regulations, provided the product is for personal use and not for resale.

• Are there specific warnings for Asian populations regarding Permethrin?
  Current safety data do not indicate ethnic differences in tolerance. However, patients with known skin sensitivities should monitor for irritation, as skin reactivity can vary individually.

• Does the formulation differ between regions such as the US, EU, and Asia?
  Region‑specific formulations may vary in concentration (1 % for lice, 5 % for scabies) and excipients used for stability. All versions contain the same active compound, but packaging and labeling conform to local regulatory requirements.

• How long does the antiparasitic effect of Permethrin last after application?
  The residual activity can prevent re‑infestation for up to 7 days, which is why a second treatment is often scheduled at that interval to target any newly hatched parasites.

• Is it safe to use Permethrin while breastfeeding?
  Topical permethrin is considered low risk during breastfeeding because systemic absorption is minimal. Nevertheless, the treated area should be kept away from the infant’s skin to avoid direct contact.

• Can Permethrin be used on pets?
  Permethrin is toxic to cats and certain dog breeds; it should not be applied to animals. Veterinary‑specific formulations exist and must be used under professional guidance.

• What is the shelf‑life of Permethrin products?
  Unopened products typically retain full potency for 2–3 years when stored properly. Once opened, the product should be used within 12 months to ensure efficacy.

Glossary

Pyrethroid

A class of synthetic chemical compounds that act on the nervous system of insects, mimicking natural pyrethrins derived from chrysanthemum flowers.

Scabies mite

Sarcoptes scabiei – a microscopic arthropod that burrows into the stratum corneum of human skin, causing intense itching and characteristic burrow tracks.

Topical application

Administration of a medication directly onto the skin or hair surface, allowing localized effect with minimal systemic absorption.

⚠️ Disclaimer

The information provided about Permethrin is for general knowledge only. It does not replace professional medical consultation. All treatment decisions should be made under the supervision of a qualified healthcare provider. We assume all readers are responsible adults capable of making informed decisions about their health. Our online pharmacy offers access to Permethrin for individuals who may have limited availability through traditional pharmacies, prescription‑based insurance schemes, or who are seeking affordable generic alternatives. Always consult your doctor before starting, changing, or discontinuing any medication.