Medically reviewed by Drugs.com. Last updated on Jan 23, 2022.
Commonly used brand name(s)
In the U.S.
- Nix Creme Rinse
- Nix Dermal Cream
- Nix Lice Killing Creme Rinse
Available Dosage Forms:
Therapeutic Class: Pediculicide
Chemical Class: Pyrethroid
Uses for permethrin
Permethrin 1% lotion is used to treat head lice infections. It acts by destroying both the lice and their eggs. The 5% cream is used to treat scabies infections by destroying the mites which cause scabies.
Before using permethrin
In deciding to use a medicine, the risks of taking the medicine must be weighed against the good it will do. This is a decision you and your doctor will make. For permethrin, the following should be considered:
Tell your doctor if you have ever had any unusual or allergic reaction to permethrin or any other medicines. Also tell your health care professional if you have any other types of allergies, such as to foods, dyes, preservatives, or animals. For non-prescription products, read the label or package ingredients carefully.
Studies on permethrin have been done only in adult patients, and there is no specific information comparing use of topical permethrin in children with use in other age groups.
Many medicines have not been studied specifically in older people. Therefore, it may not be known whether they work exactly the same way they do in younger adults or if they cause different side effects or problems in older people. There is no specific information comparing use of topical permethrin in the elderly with use in other age groups.
Studies in women suggest that this medication poses minimal risk to the infant when used during breastfeeding.
Interactions with medicines
Although certain medicines should not be used together at all, in other cases two different medicines may be used together even if an interaction might occur. In these cases, your doctor may want to change the dose, or other precautions may be necessary. Tell your healthcare professional if you are taking any other prescription or nonprescription (over-the-counter [OTC]) medicine.
Interactions with food/tobacco/alcohol
Certain medicines should not be used at or around the time of eating food or eating certain types of food since interactions may occur. Using alcohol or tobacco with certain medicines may also cause interactions to occur. Discuss with your healthcare professional the use of your medicine with food, alcohol, or tobacco.
Other medical problems
The presence of other medical problems may affect the use of permethrin. Make sure you tell your doctor if you have any other medical problems, especially:
The presence of other medical problems may affect the use of topical permethrin. Make sure you tell your doctor if you have other medical problems, especially:
- Severe inflammation of the scalp—Use of permethrin may make the condition worse
Proper use of permethrin
Keep permethrin away from the eyes. If you accidentally get some in your eyes, flush them thoroughly with water at once.
Permethrin lotion which is used to treat lice, comes in a container that holds only one treatment. Use as much of the medicine as you need and discard any remaining lotion properly.
For the treatment of head lice (1% lotion):
- Shampoo the hair and scalp using regular shampoo.
- Thoroughly rinse and towel dry the hair and scalp.
- Allow hair to air dry for a few minutes.
- Shake the permethrin lotion well before applying.
- Thoroughly wet the hair and scalp with the permethrin lotion. Be sure to cover the areas behind the ears and on the back of the neck also. Allow the lotion to remain in place for 10 minutes.
- Then, rinse the hair and scalp thoroughly and dry with a clean towel.
- When the hair is dry, you may want to comb the hair with a fine-toothed comb to remove any remaining nits (eggs) or nit shells.
Head lice can be easily transferred from one person to another by direct contact with clothing, hats, scarves, bedding, towels, washcloths, hairbrushes and combs, or hairs from infected persons. Therefore, all members of your household should be examined for head lice and should receive treatment if they are found to be infected. If you have any questions about this, check with your doctor.
For the treatment of scabies (5% cream):
- Read package directions carefully before using.
- Thoroughly wash and dry skin.
- Massage the cream into the skin from the head to the soles of the feet, paying special attention to creases in the skin, hands, feet, between fingers and toes, underarms, and groin.
- Scabies rarely infests the scalp of adults, although the hairline, neck, side of the head, and forehead may be infested in older people and in infants. Infants should be treated on the scalp, side of the head, and forehead.
- Leave the permethrin cream on the skin for 8 to 14 hours.
- Wash off by taking a shower or bath.
- Change into clean clothes.
- After treatment, itching may continue for up to 4 weeks.
The dose of permethrin will be different for different patients. Follow your doctor's orders or the directions on the label. The following information includes only the average doses of permethrin. If your dose is different, do not change it unless your doctor tells you to do so.
The amount of medicine that you take depends on the strength of the medicine. Also, the number of doses you take each day, the time allowed between doses, and the length of time you take the medicine depend on the medical problem for which you are using the medicine.
- For topical dosage forms (cream and lotion):
- For head lice:
- Adults and children 2 years of age and older—Apply to the hair and scalp one time.
- Children up to 2 years of age—Use and dose must be determined by your doctor.
- For scabies:
- Adults and children 2 months of age and older—Apply to the skin one time.
- Children up to 2 months of age—Use and dose must be determined by your doctor.
- For head lice:
Store the medicine in a closed container at room temperature, away from heat, moisture, and direct light. Keep from freezing.
Keep out of the reach of children.
Do not keep outdated medicine or medicine no longer needed.
Precautions while using permethrin
To prevent reinfection or spreading of the infection to other people, good health habits are required. These include the following:
- Machine wash all clothing (including hats, scarves, and coats), bedding, towels, and washcloths in very hot water and dry them by using the hot cycle of a dryer for at least 20 minutes. Clothing or bedding that cannot be washed should be dry cleaned or sealed in an airtight plastic bag for 2 weeks.
- Shampoo all wigs and hairpieces.
- Wash all hairbrushes and combs in very hot soapy water (above 130 °F) for 5 to 10 minutes and do not share them with other people.
- Clean the house or room by thoroughly vacuuming upholstered furniture, rugs, and floors.
- Wash all toys in very hot soapy water (above 130 °F) for 5 to 10 minutes or seal in an airtight plastic bag for 2 weeks. This is especially important for stuffed toys used on the bed.
Permethrin side effects
Along with its needed effects, a medicine may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.
Some side effects may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects. Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:
Less common or rare
- Burning, itching, numbness, rash, redness, stinging, swelling, or tingling of the scalp
Other side effects not listed may also occur in some patients. If you notice any other effects, check with your healthcare professional.
Call your doctor for medical advice about side effects. You may report side effects to the FDA at 1-800-FDA-1088.
Frequently asked questions
More about permethrin topical
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- Drug class: topical anti-infectives
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