From the Guidelines
To use Nix cream for head lice, apply it to damp hair that has been shampooed with a nonconditioning shampoo and towel dried, leave it on for 10 minutes, and then rinse it off, with a repeat application in 7 to 10 days if live lice are seen. This treatment is based on the recommendation that 1% permethrin lotion is one of the drugs of choice for head lice, as stated in the study published in Pediatrics 1. The application process is crucial, as conditioners and silicone-based additives in shampoos can impair permethrin adherence to the hair shaft and reduce its residual effect.
Some key points to consider when using Nix cream for head lice include:
- Applying the cream to damp hair that has been shampooed with a nonconditioning shampoo and towel dried
- Leaving the cream on for 10 minutes before rinsing it off
- Repeating the application in 7 to 10 days if live lice are seen, as resistance to 1% permethrin has been reported, although the prevalence of this resistance is not known 1
- Being aware that permethrin leaves a residue on the hair designed to kill nymphs emerging from eggs not killed with the first application
- Considering the potential for side effects, such as pruritus, erythema, and edema, although permethrin is less allergenic than pyrethrins and does not cause allergic reactions in individuals with plant allergies 1.
It's also important to note that other treatments, such as pyrethrins plus piperonyl butoxide, lindane, and malathion, are available, but 1% permethrin lotion is currently recommended as one of the drugs of choice for head lice, as stated in the study published in American Family Physician 1.
From the FDA Drug Label
DOSAGE AND ADMINISTRATION Adults and children Thoroughly massage Permethrin Cream, 5% into the skin from the head to the soles of the feet. The cream should be removed by washing (shower or bath) after 8 to 14 hours. ONE APPLICATION IS GENERALLY CURATIVE. To use Nix cream, which contains permethrin, thoroughly massage the cream into the skin from the head to the soles of the feet.
- Apply a sufficient amount, usually 30 grams for an average adult.
- Leave the cream on for 8 to 14 hours before washing it off.
- One application is generally curative, but retreatment may be necessary if living mites are still present after 14 days 2.
From the Research
Nix Cream Instructions
- Nix cream is a treatment for scabies and lice, and its instructions can be inferred from the treatment guidelines for these conditions.
- According to the studies, permethrin 5% cream is a common treatment for scabies 3, 4, 5, 6.
- The typical instructions for using permethrin 5% cream for scabies are to apply the cream to the entire body, from the neck down, and leave it on for 8-14 hours before washing it off 4.
- For scabies, permethrin 5% cream is often repeated in 4-7 days to ensure that all mites are killed 4, 6.
- It is essential to note that Nix cream is not explicitly mentioned in the provided studies, but permethrin 5% cream is a common treatment for scabies and lice, and its instructions can be used as a reference.
- Environmental measures, such as washing and drying clothing and bedding, are also important to prevent recurrent infestation 3, 4.