Pyrethrins and Piperonyl Butoxide



A-200® Maximum Strength [OTC]; Pronto®[OTC]; Pyrinyl Plus®[OTC]; RID® Maximum Strength [OTC]; Tisit®[OTC]; Tisit® Blue Gel [OTC]







Pyrethrins and Piperonyl Butoxide

(PI re thrins & pi PER oh nil byoo TOX ide)

U.S. Brand Names
A-200® Maximum Strength [OTC]; Pronto®[OTC]; Pyrinyl Plus®[OTC]; RID® Maximum Strength [OTC]; Tisit®[OTC]; Tisit® Blue Gel [OTC]
Canadian Brand Names
Pronto® Lice Control; R & C™ II; R & C™ Shampoo/Conditioner; RID® Mousse
Pharmacologic Category
Antiparasitic Agent, Topical; Pediculocide; Shampoo, Pediculocide
Reasons not to take this medicine
  • If you have an allergy to pyrethrins, piperonyl butoxide, ragweed, chrysanthemums or any other part of this medicine.
  • Tell healthcare provider if you are allergic to any medicine. Make sure to tell about the allergy and how it affected you. This includes telling about rash; hives; itching; shortness of breath; wheezing; cough; swelling of face, lips, tongue, or throat; or any other symptoms involved.
What is this medicine used for?
  • This medicine is used to treat lice.
How does it work?
  • Pyrethrins and piperonyl butoxide injure the insects and treat the infection.
How is it best taken?
  • Spray:
  • Do not use on people or animals.
  • For use on non-washable items only.
  • Spray on infested area and let dry completely.
  • Vacuum rugs and carpets. Throw away vacuum cleaner bags after use.
  • All other forms:
  • Do not take this medicine by mouth. For skin only. Keep out of mouth, nose, and eyes (may burn).
  • Wash hands before and after use.
  • Clean affected area before use. Make sure to dry well.
  • Wash all bedding, towels, and recently worn clothes in hot water or have them dry cleaned.
  • Cream, oil, and shampoo:
  • Shake well before use.
  • Do not wet hair or affected area with water before applying.
  • Apply just enough to lightly coat hair or affected area.
  • Work into hair and scalp or affected area gently.
  • Leave on for 10 minutes.
  • Leave affected area uncovered while medicine is on.
  • After 10 minutes, apply a small amount of warm water and soap or regular shampoo to hair and lather.
  • Rinse completely.
  • Wash hands.
  • Dry with a towel.
  • Use special nit comb or tweezers to remove dead nits (lice eggs) from hair.
  • Foam:
  • Shake well before use.
  • Do not wet hair or affected area with water before applying.
  • Apply just enough to lightly coat hair or affected area.
  • Work into hair and scalp or affected area gently.
  • Leave on for 10 minutes.
  • Leave affected area uncovered while medicine is on.
  • After 10 minutes, apply a small amount of warm water and soap or regular shampoo.
  • Wash hands.
  • Dry with a towel.
  • Use special nit comb or tweezers to remove dead nits (lice eggs) from hair.
  • Gel and liquid:
  • Do not wet hair or affected area with water before applying.
  • Apply just enough to lightly coat hair or affected area.
  • Work into hair and scalp or affected area gently.
  • Leave on for 10 minutes.
  • Leave affected area uncovered while medicine is on.
  • After 10 minutes, apply a small amount of warm water and soap or regular shampoo.
  • Wash hands.
  • Dry with a towel.
  • Use special nit comb or tweezers to remove dead nits (lice eggs) from hair.
What do I do if I miss a dose? (does not apply to patients in the hospital)
  • Do not use a double dose or extra doses.
What are the precautions when taking this medicine?
  • Follow instructions for use carefully.
  • Check medicines with healthcare provider. This medicine may not mix well with other medicines.
  • Tell healthcare provider if you are pregnant or plan on getting pregnant.
  • Tell healthcare provider if you are breast-feeding.
What are some possible side effects of this medicine?
  • Scalp irritation.
  • Skin irritation.
  • Short-term discomfort after use.
What should I monitor?
  • Change in condition being treated. Is it better, worse, or about the same?
Reasons to call healthcare provider immediately
  • If you suspect an overdose, call your local poison control center immediately or dial 911.
  • Signs of a life-threatening reaction. These include wheezing; chest tightness; fever; itching; bad cough; blue skin color; fits; or swelling of face, lips, tongue, or throat.
  • Difficulty breathing.
  • Severe skin irritation.
  • Any rash.
  • No improvement in condition or feeling worse.
How should I store this medicine?
  • Store at room temperature.
  • Protect foam from heat.
General statements
  • If you have a life-threatening allergy, wear an allergy identification bracelet at all times.
  • Do not share your medicine with others and do not take anyone else's medicine.
  • Keep all medicine out of the reach of children and pets.
  • Keep a list of all your medicines (prescription, natural products, supplements, vitamins, over-the-counter) with you. Give this list to healthcare provider (doctor, nurse, nurse practitioner, pharmacist, physician assistant).
  • Talk with healthcare provider before starting any new medicine, including over-the-counter, natural products, or vitamins.
Brand Names: