This medication is used to treat head lice, tiny insects that infest and irritate your scalp. Permethrin is also used to help avoid infestation in people who have close contact with someone who has head lice. It belongs to a class of drugs known as pyrethrins. Permethrin works by paralyzing and killing lice and their eggs (nits).
Apply this medication as soon as possible after it is prescribed. When treating head lice, apply this medication to the hair and scalp only. First wash hair with your regular shampoo, but do not use conditioner. Thoroughly rinse the shampoo out with water, and towel-dry hair. Shake this medication well before using. Cover your eyes with a towel while applying this medication. Completely cover the hair and scalp with the medicine (especially behind the ears and on the hairline at the neck). Avoid getting permethrin in your nose, ears, mouth, vagina, or eyes. If the medicine gets in any of these areas, flush with plenty of water. Do not use more medication than prescribed. Leave the medication on your hair for 10 minutes or as directed by your doctor, then rinse with warm water. Towel-dry your hair and comb out any tangles. A single permethrin treatment can help prevent lice from coming back for 14 days. If eyebrows or eyelashes are infested, do not apply this medication to those areas without first consulting your doctor.
Head lice lay small white eggs (nits) at the base of hair close to the scalp, especially on the hairline at the back of the neck and behind the ears. After treatment with this medication, the infected person should be checked by another person for lice and nits using a magnifying glass and bright light. To remove nits, use the special comb provided, and follow the instructions on the package. After combing, re-check the entire head every day for nits you might have missed. Remove any nits by combing, by hand using a disposable glove, or by cutting them out. If live lice are seen 7 days or more after treatment, a second treatment with permethrin or another drug may be needed.
Inform your doctor if your condition persists or worsens.
Scalp irritation, including itching, swelling, or redness may occur with head lice and temporarily worsen after treatment with permethrin. Mild burning, stinging, tingling, or numbness may also occur. If any of these effects persist or worsen, tell your doctor or pharmacist promptly.
Remember that your doctor has prescribed this medication because he or she has judged that the benefit to you is greater than the risk of side effects. Many people using this medication do not have serious side effects.
A very serious allergic reaction to this drug is rare. However, seek immediate medical attention if you notice any symptoms of a serious allergic reaction, including: rash, itching/swelling (especially of the face/tongue/throat), severe dizziness, trouble breathing.
This is not a complete list of possible side effects. If you notice other effects not listed above, contact your doctor or pharmacist.
In the US -
Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088 or at www.fda.gov/medwatch.
In Canada - Call your doctor for medical advice about side effects. You may report side effects to Health Canada at 1-866-234-2345.
Before using permethrin, tell your doctor or pharmacist if you are allergic to it; or if you have any other allergies. This product may contain inactive ingredients, which can cause allergic reactions or other problems. Talk to your pharmacist for more details.
Constant or forceful scratching of the skin/scalp may lead to a bacterial skin infection. Tell your doctor right away if you develop worsening redness or pus.
Tell your doctor if you are pregnant before using this medication.
Your doctor or pharmacist may already be aware of any possible drug interactions and may be monitoring you for them. Do not start, stop, or change the dosage of any medicine before checking with your doctor or pharmacist first.
Before using this medication, tell your doctor or pharmacist of all prescription and nonprescription/herbal products you may use.
Keep a list of all your medications with you, and share the list with your doctor and pharmacist.
This medicine may be harmful if swallowed. If someone has overdosed and has serious symptoms such as passing out or trouble breathing, call 911. Otherwise, call a poison control center right away. US residents can call their local poison control center at 1-800-222-1222. Canada residents can call a provincial poison control center.
One application is usually all that is needed. To avoid giving lice to another person or getting them again, all head wear, scarves, coats, and bed linens should be machine-washed with hot water and dried in a dryer (at high setting) for at least 20 minutes, dry cleaned, sealed in a plastic bag for 2 weeks, or sprayed with a disinfectant that kills lice. Brushes or combs should be soaked in hot water (hotter than 130 degrees F/54 degrees C) for 10 minutes, soaked in alcohol for 1 hour, or thrown away. Furniture and floors should be thoroughly vacuumed.
People who are in close contact with the infected person, such as members of the same household, should also be checked for lice and nits. Treatment may be considered to prevent infestation even if live lice are not found on them.
Store at room temperature between 59-77 degrees F (15-25 degrees C) away from light and moisture. Do not store in the bathroom. Keep all medicines away from children and pets.
Do not flush medications down the toilet or pour them into a drain unless instructed to do so. Properly discard this product when it is expired or no longer needed. Consult your pharmacist or local waste disposal company for more details about how to safely discard your product.Information last revised July 2016. Copyright(c) 2016 First Databank, Inc.
With WebMD's Medicine Cabinet, you can check interactions with drugs.Go to medicine cabinet