Spinosad

Pronunciation: SPIN-oh-sad
Class: Pediculicide

Trade Names

Natroba
- Suspension, topical 0.9%

Pharmacology

Causes neuronal excitation in insects. After periods of hyperexcitation, lice become paralyzed and die.

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Pharmacokinetics

Absorption

After a single topical application, plasma levels of spinosad were below the limit of quantitation (3 ng/mL).

Indications and Usage

Treatment of head lice infestation.

Contraindications

None well documented.

Dosage and Administration

Topical Apply sufficient spinosad suspension to cover dry scalp, then apply to dry hair. Depending on hair length, apply up to 120 mL (1 bottle) to adequately cover scalp and hair. Leave on for 10 min, then thoroughly rinse off with warm water. If live lice are seen 7 days after the first treatment, a second treatment should be applied.

General Advice

• For topical use only; not for oral, ophthalmic, or intravaginal use.
• Avoid contact with eyes.
• Shake bottle well before use.

Storage/Stability

Store between 59° and 86°F.

Drug Interactions

None well documented.

Adverse Reactions

EENT

Ocular erythema (2%).

Local

Application-site erythema (3%); application-site irritation (1%).

Precautions

Pregnancy

Category B .

Lactation

Spinosad is not systemically absorbed and, therefore, will not be present in human milk. Benzyl alcohol, however, may be systemically absorbed. A breast-feeding woman may choose to pump and discard breast milk for 8 hours after use to avoid infant ingestion of benzyl alcohol.

Children

Safety and efficacy are not established in children younger than 4 y of age. Not recommended in children younger than 6 mo of age because of the potential for increased systemic absorption because of a high ratio of skin surface area to body mass and the potential for an immature skin barrier.

Benzyl alcohol

Contains benzyl alcohol, which has been associated with serious adverse reactions (eg, “gasping syndrome”) and death in neonates and low–birth-weight infants.

Overdosage

Symptoms

None well documented.

Patient Information

• Instruct patients to shake bottle well immediately prior to use.
• Advise patients to use only on dry scalp and hair, not to swallow, and to avoid contact with eyes. If suspension gets in or near the eyes, instruct patients to rinse thoroughly with water.
• Teach patient or caregiver the proper technique for applying suspension: apply suspension on dry scalp and hair in an amount just sufficient to adequately cover hair and scalp; leave on for 10 min and then thoroughly rinse with warm water.
• Instruct patients to wash hands after applying suspension.
• Advise that use on children should only be under direct supervision of an adult.
• Advise pregnant or breast-feeding women to consult a health care provider before use.

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