Spinosad 0.9% Topical Suspension Availability
Spinosad 0.9% topical suspension is FDA-approved and available in the United States as a prescription medication for the treatment of head lice (pediculosis capitis) in patients aged 4 years and older. 1
Regulatory Status and Indications
Spinosad 0.9% suspension received FDA approval in 2011 for head lice treatment and is marketed as a prescription-only topical pediculicide in the US 2, 3
In 2021, the FDA expanded approval to include scabies treatment, making it the first single-dose topical scabicide approved for classical scabies in patients older than 4 years 4
The medication is specifically indicated for pediculosis capitis (head lice infestation) and scabies, particularly for cases resistant to over-the-counter permethrin products 1
Clinical Efficacy Evidence
Spinosad demonstrates superior efficacy compared to permethrin 1%, with 84.6-86.7% of patients lice-free 14 days after treatment versus only 42.9-44.9% with permethrin (p < 0.001) 5
Most patients require only a single application of spinosad without nit combing, whereas permethrin typically requires two treatments with mandatory nit combing 3, 5
The medication is both pediculicidal and ovicidal, killing both live lice and eggs (nits), which contributes to its single-dose effectiveness 2, 6
Mechanism and Safety Profile
Spinosad works by interfering with nicotinic acetylcholine receptors in insects, causing neuronal excitation and paralysis through neuromuscular fatigue 2, 6
Systemic absorption is not detectable after topical application, making it safe for use in children aged 4 years and older 2
The most common adverse events are mild to moderate, including application-site erythema and ocular irritation, with no serious adverse events reported in clinical trials 2, 3, 5
Practical Considerations
Spinosad is effective against permethrin-resistant lice populations, addressing a major limitation of over-the-counter treatments 1, 2
The medication does not require nit combing, improving patient adherence and convenience compared to permethrin-based treatments 3, 5
For lice resistant to all topical agents, oral ivermectin remains an alternative option for patients weighing over 15 kg 1
Note: Availability may vary by country. The evidence provided specifically confirms FDA approval and availability in the United States. For availability in other locations, consult local regulatory authorities and pharmacy networks.