II. Indications
III. Contraindications
- Ragweed allergy (relative; may cross-react to Pyrethrins)
IV. Mechanism
- Pyrethrins are Insecticides extracted from chrysanthemums
- Pyrethroids are longer acting derivatives (Permethrin)
- RID is a combination of Pyrethrin and Piperonyl Butoxide
- Piperonyl Butoxide is a synthetic derivative of benzodioxole
- Piperonyl Butoxide is an Insecticide synergist that inhibits Insect microsomal enzyme detoxification activity
- Piperonyl Butoxide is toxic if ingested (Seizures, hepatotoxicity, nephrotoxicity, carcinogenic)
-
Pesticide Agents related to Pyrethrins
- Allethrin
- Cyfluthrin
- Cypermethrin
- Deltamethrin
- Dimethrin
- Fenothrin
- Fenvalerate
- Permethrin
- Remethrin
V. Background
- Advantages
- Available without a prescription
- Convenient (only 10 minute application)
- Disadvantages
- Does not kill all unhatched eggs
- Requires repeat application in 5-7 days
- Treatment failures are common
VI. Medications
- Pyrethrin with Piperonyl Butoxide (RID)
- Shampoo: 60, 120, 240 ml
VII. Dosing: Lice Treatment
VIII. Adverse Effects
- See Pyrethroid Toxicity
- Mechanism
- Nerve toxicity is rare in humans
- Minimal absorption and rapid hepatic metabolism
- Effects
- Allergic Reaction in 1-3%
- Nasal congestion
- Asthma exascerbation
- Topical effects
- Paresthesias (hands and face)
- Rare neurologic effects
- Allergic Reaction in 1-3%
IX. Safety
- Pregnancy Category C
- Unknown safety in Lactation
X. Resources
- Piperonyl Butoxide and Pyrethrum Extract Shampoo (DailyMed)