Piperonyl butoxide with pyrethrins is an ingredient found in medicines to kill lice. Poisoning occurs when someone swallows the product or too much of the product touches the skin.
This article is for information only. DO NOT use it to treat or manage an actual poison exposure. If you or someone you are with has an exposure, call the local emergency number (such as 911), or the local poison control center can be reached directly by calling the national toll-free Poison Help hotline (1-800-222-1222) from anywhere in the United States.
Poisonous Ingredient
The ingredients include:
- Piperonyl butoxide
- Pyrethrins
The poisonous ingredients may go by other names.
Where Found
In addition to head lice lotions or shampoos which contain piperonyl butoxide with pyrethrins and may be applied to humans as lotions or shampoos, there are more than 2,500 pesticide products that contain piperonyl butoxide with pyrethrins.
Examples of products that contain piperonyl butoxide with pyrethrins include:
- A-200
- Barc (also contains petroleum distillates)
- Lice-Enz Foam Kit
- Pronto
- Pyrinex (also contains petroleum distillates)
- Pyrinyl (also contains kerosene)
- Pyrinyl II
- R & C spray
- Rid (also contains petroleum distillates and benzyl alcohol)
- Tisit
- Tisit Blue (also contains petroleum distillates)
- Triple X Kit (also contains petroleum distillates)
Products with other names may also contain piperonyl butoxide with pyrethrins.
Symptoms
Symptoms of poisoning from these products include:
- Difficulty breathing, shortness of breath, wheezing.
- Eye irritation if it touches the eyes. There are reports of A-200 Pyrinate causing corneal erosions in children.
- Muscle weakness.
- Convulsions, tremors.
- Nausea and vomiting.
- Rash (allergic reaction).
- Salivating more than usual.
- Sneezing.
- Chest pain.
- Coma.
Home Care
Seek medical help right away. Do NOT make a person throw up unless poison control or a health care provider tells you to. If the chemical is in the eyes, flush with lots of water for at least 15 minutes.
Before Calling Emergency
Have this information ready:
- The person's age, weight, and condition
- Name of the product (ingredients and strength, if known)
- Time it was swallowed
- The amount swallowed
Poison Control
The local poison control center can be reached directly by calling the national toll-free Poison Help hotline (1-800-222-1222) from anywhere in the United States. This national hotline will let you talk to experts in poisoning. They will give you further instructions.
This is a free and confidential service. All local poison control centers in the United States use this national number. You should call if you have any questions about poisoning or poison prevention. It does NOT need to be an emergency. You can call for any reason, 24 hours a day, 7 days a week.
You can also get online poison help now at Poisonhelp.org. Just enter the product, poison, or medicine to get expert help.
What to Expect at the Emergency Room
If you go to the emergency room, take the container for the poison with you, if possible.
Your provider will measure and monitor your vital signs, including temperature, pulse, breathing rate, and blood pressure. Symptoms will be treated. The person may receive:
- Cleaning of exposed skin
- Washing and examination of eyes as needed
- Treatment of allergic reactions as needed
If the poison was swallowed, tests may include:
- Blood and urine tests
- Chest x-ray
- CT scan (advanced imaging) of the brain for neurologic symptoms
- Electrocardiogram (ECG), or heart tracing
Treatment may include:
- Activated charcoal
- Breathing support, including oxygen, tube through the mouth into the lungs, and breathing machine (ventilator)
- Fluids through a vein (IV)
- Laxative
- Medicines to treat symptoms
Outlook (Prognosis)
Most symptoms are seen in people who are allergic to pyrethrins. Piperonyl butoxide is not very toxic, but extreme exposures may result in more severe symptoms.
Alternative Names
Pyrethrins poisoning
References
Brandenburg MA, Lafave M, Butterwick DJ. Ranch and rodeo medicine. In: Auerbach PS, Cushing TA, Harris NS, eds. Auerbach's Wilderness Medicine. 7th ed. Philadelphia, PA: Elsevier; 2017:chap 37.
Meehan TJ. Approach to the poisoned patient. In: Walls RM, ed. Rosen's Emergency Medicine: Concepts and Clinical Practice. 10th ed. Philadelphia, PA: Elsevier; 2023:chap 135.
Theobald JL, Corcoran JN. Poisoning. In: Kliegman RM, St. Geme JW, Blum NJ, et al, eds. Nelson Textbook of Pediatrics. 22nd ed. Philadelphia, PA: Elsevier; 2025:chap 94.
Welker KL, Thompson TM. Pesticides. In: Walls RM, ed. Rosen's Emergency Medicine: Concepts and Clinical Practice. 10th ed. Philadelphia, PA: Elsevier; 2023:chap 152.
Review Date 7/1/2025
Updated by: Jesse Borke, MD, CPE, FAAEM, FACEP, Attending Physician at Kaiser Permanente, Orange County, CA. Also reviewed by David C. Dugdale, MD, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.