Description and Brand Names

Drug information provided by: Merative, Micromedex®

US Brand Name

  1. A200 Maximum Strength
  2. A200 Time-Tested Formula
  3. Lice-X
  4. Licide
  5. Medi-Lice Maximum Strength
  6. Pronto Maximum Strength
  7. Pyrinex
  8. Pyrinyl
  9. Rid
  10. Tisit

Descriptions


Medicine containing pyrethrins is used to treat head, body, and pubic lice infections. This medicine is absorbed by the lice and destroys them by acting on their nervous systems. It does not affect humans in this way. The piperonyl butoxide is included to make the pyrethrins more effective in killing the lice. This combination medicine is known as a pediculicide.

This medicine is available without a prescription.

This product is available in the following dosage forms:

  • Foam
  • Gel/Jelly
  • Liquid
  • Shampoo

Before Using

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 this medicine, the following should be considered:

Allergies

Tell your doctor if you have ever had any unusual or allergic reaction to this medicine 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.

Pediatric

Although there is no specific information comparing use of pyrethrins and piperonyl butoxide combination in children with use in other age groups, this medicine is not expected to cause different side effects or problems in children than it does in adults.

Geriatric

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. Although there is no specific information comparing use of pyrethrins and piperonyl butoxide combination medicine in the elderly with use in other age groups, this medicine is not expected to cause different side effects or problems in older people than it does in younger adults.

Breastfeeding

There are no adequate studies in women for determining infant risk when using this medication during breastfeeding. Weigh the potential benefits against the potential risks before taking this medication while breastfeeding.

Drug Interactions

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.

Other Interactions

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 this medicine. Make sure you tell your doctor if you have any other medical problems, especially:

  • Inflammation of the skin (severe)—Use of pyrethrins and piperonyl butoxide combination may make the condition worse

Proper Use

Pyrethrins and piperonyl butoxide combination medicine usually comes with patient directions. Read them carefully before using this medicine.

Use this medicine only as directed. Do not use more of it and do not use it more often than recommended on the label. To do so may increase the chance of absorption through the skin and the chance of side effects.

Keep pyrethrins and piperonyl butoxide combination medicine away from the mouth and do not inhale it. This medicine is harmful if swallowed or inhaled.

To lessen the chance of inhaling this medicine, apply it in a well-ventilated room (for example, one with free flowing air or with a fan turned on).

Keep this medicine away from the eyes and other mucous membranes, such as the inside of the nose, mouth, or vagina, because it may cause irritation. If you accidentally get some in your eyes, flush them thoroughly with water at once.

Do not apply this medicine to the eyelashes or eyebrows . If they become infected with lice, check with your doctor.

To use the gel or solution form of this medicine:

  • Apply enough medicine to thoroughly wet the dry hair and scalp or skin. Allow the medicine to remain on the affected areas for exactly 10 minutes.
  • Then, thoroughly wash the affected areas with warm water and soap or regular shampoo. Rinse thoroughly and dry with a clean towel.

To use the shampoo form of this medicine:

  • Apply enough medicine to thoroughly wet the dry hair and scalp or skin. Allow the medicine to remain on the affected areas for exactly 10 minutes.
  • Then use a small amount of water and work shampoo into the hair and scalp or skin until a lather forms. Rinse thoroughly and dry with a clean towel.

After rinsing and drying, use a nit removal comb (special fine-toothed comb, usually included with this medicine) to remove the dead lice and eggs (nits) from hair.

Immediately after using this medicine, wash your hands to remove any medicine that may be on them.

This medicine should be used again in 7 to 10 days after the first treatment in order to kill any newly hatched lice.

Lice can easily move from one person to another by close body contact. This can happen also by direct contact with such things as clothing, hats, scarves, bedding, towels, washcloths, hairbrushes and combs, or the hair of infected persons. Therefore, all members of your household should be examined for lice and receive treatment if they are found to be infected.

To use this medicine for pubic (crab) lice:

  • Your sexual partner may also need to be treated, since the infection may spread to persons in close contact. If your partner is not being treated or if you have any questions about this, check with your doctor.

Dosing

The dose of this medicine 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 this medicine. 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 (gel, solution shampoo, and topical solution):
    • For head, body, or pubic lice:
      • Adults and children—Use one time, then repeat one time in seven to ten days.

Storage

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

To prevent reinfection or spreading of the infection to other people, good health habits are also required. These include the following:

  • For head lice
    • 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 a 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.
  • For body lice
    • Machine wash all clothing, 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 a plastic bag for 2 weeks.
    • Clean the house or room by thoroughly vacuuming upholstered furniture, rugs, and floors.
  • For pubic lice
    • Machine wash all clothing (especially underwear), 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 a plastic bag for 2 weeks.
    • Scrub toilet seats frequently.

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.

Check with your doctor as soon as possible if any of the following side effects occur:

Less common or rare

  1. Skin irritation not present before use of this medicine
  2. skin rash or infection
  3. sneezing (sudden attacks of)
  4. stuffy or runny nose
  5. wheezing or difficulty in breathing

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.

Portions of this document last updated: Feb. 01, 2024

Original article: https://www.mayoclinic.org/es-es/drugs-supplements/pyrethrum-extract-and-piperonyl-butoxide-topical-route/description/drg-20068537