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ANTIPARASITIC PRODUCTS, INSECTICIDES AND REPELLENTS › ECTOPARASITICIDES, INCL. SCABICIDES, INSECTICIDES AND REPELLENTS › INSECTICIDES AND REPELLENTS › Pyrethrines
tetramethrin
P03BA04
Forms & Strengths
- Topical liquid (various concentrations, typically 0.2% - 2%)
- Aerosol sprays and combination insecticidal formulations
- Shampoos and powders for veterinary and human ectoparasite use
Adult Dosing
- Topical application: Apply sufficient volume of formulation to cover affected skin/hair areas infested with lice, fleas, or ticks
- Leave on for specified duration (usually 10 minutes) per product labeling, then rinse thoroughly
- Repeat application after 7-10 days if re-infestation or persistence is observed
Pediatric Dosing
- Children >2 years: Apply topical formulation sparingly to infested areas following specific product labeling directions
- Avoid use in infants <2 years unless explicitly directed by a physician due to potential systemic absorption risks
- Rinse thoroughly and avoid contact with eyes and mucous membranes
Indications
- Eradication of head lice (Pediculus humanus capitis)
- Treatment of pubic lice (Pthirus pubis)
- Control of ectoparasite infestations such as fleas and ticks in household or veterinary settings
Mechanism of Action
- Type I synthetic pyrethroid insecticide
- Interferes with sodium ion channel gating in the nerve membranes of insects
- Causes prolonged repetitive discharges and paralysis ('knockdown effect'), leading to insect death
Contraindications
- Hypersensitivity to tetramethrin, other pyrethroids, or pyrethrins
- Application on broken, inflamed, or infected skin
- Direct application to eyes, mucous membranes, or urethral meatus
Adverse Reactions
- Local skin irritation, burning, stinging, or erythema at application site
- Contact dermatitis or allergic skin reactions
- Transient paresthesia (tingling or numbness) of the skin
- Ocular irritation if accidental contact with eyes occurs
Drug Interactions
- Potential synergistic toxicity with other neurotoxic insecticides (e.g., organophosphates, carbamates)
- Enhanced skin absorption when used concomitantly with topical penetration enhancers or oily vehicles
Curated Content: Needs Vetting Before Put to Clinical Use