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Medically reviewed by Last updated on Oct 17, 2020.


(SPIN oh sad)

Index Terms

  • NatrOVA

Dosage Forms

Excipient information presented when available (limited, particularly for generics); consult specific product labeling.

Suspension, External:

Natroba: 0.9% (120 mL) [contains benzyl alcohol, cetearyl alcohol, fd&c yellow #6 (sunset yellow), isopropyl alcohol, propylene glycol]

Generic: 0.9% (120 mL)

Brand Names: U.S.

  • Natroba

Pharmacologic Category

  • Antiparasitic Agent, Topical
  • Pediculocide


Insect paralysis and death is caused by central nervous system excitation and involuntary muscle contractions. Spinosad is thought to be both pediculicidal and ovicidal (Stough, 2009).


Not absorbed topically (<3 ng/mL in a pediatric patient plasma sampling study); absorption of the benzyl alcohol was not analyzed in this study.

Use: Labeled Indications

Head lice: Topical treatment of head lice (Pediculosis capitis) infestation in adults and children ≥6 months of age


There are no contraindications listed in the manufacturer’s labeling

Dosing: Adult

Head lice: Topical: Apply sufficient amount to cover dry scalp and completely cover dry hair; 120 mL may be necessary depending on the length of hair. If live lice are seen 7 days after first treatment, repeat with second application.

Dosing: Geriatric

Refer to adult dosing.

Dosing: Pediatric

Head lice: Infants ≥6 months, Children, and Adolescents: Topical: Suspension: Apply sufficient amount to cover dry scalp and completely cover dry hair (maximum single application dose: 120 mL); leave on for 10 minutes and then rinse out with warm water. If live lice are seen 7 days after first treatment, repeat with second application.


Topical suspension; for external use only. Shake bottle well. Apply to dry scalp and rub gently until the scalp is thoroughly moistened, then apply to dry hair; completely covering scalp and hair. Wash hands after application. Leave on for 10 minutes (start timing treatment after the scalp and hair have been completely covered). The hair should then be rinsed thoroughly with warm water. Shampoo may be used immediately after the product is completely rinsed off. If live lice are seen 7 days after the first treatment, repeat with second application. Avoid contact with the eyes. Nit combing is not required, although a fine-tooth comb may be used to remove treated lice and nits.

Spinosad should be a portion of a whole lice removal program, which should include washing or dry cleaning all clothing, hats, bedding and towels recently worn or used by the patient and washing combs, brushes, and hair accessories in hot water.


Store at 25°C (77°F); excursions permitted between 15°C to 30°C (59°F to 86°F).

Drug Interactions

There are no known significant interactions.

Adverse Reactions

The following adverse drug reactions and incidences are derived from product labeling unless otherwise specified.

1% to 10%: Dermatologic: Application site erythema (3%), erythema of eyelid (2%), application site irritation (1%)

<1%, postmarketing, and/or case reports: Alopecia, application site reactions (dryness, exfoliation), dry skin


Dosage form specific issues:

• Benzyl alcohol and derivatives: Some dosage forms may contain benzyl alcohol; large amounts of benzyl alcohol (≥99 mg/kg/day) have been associated with a potentially fatal toxicity (“gasping syndrome”) in neonates; the “gasping syndrome” consists of metabolic acidosis, respiratory distress, gasping respirations, CNS dysfunction (including convulsions, intracranial hemorrhage), hypotension, and cardiovascular collapse (AAP ["Inactive" 1997]; CDC, 1982); some data suggests that benzoate displaces bilirubin from protein binding sites (Ahlfors, 2001); avoid or use dosage forms containing benzyl alcohol with caution in neonates. See manufacturer’s labeling.

Other warnings/precautions:

• Appropriate use: For topical use on scalp and scalp hair only; not for oral, ophthalmic, or intravaginal use. Avoid contact with eyes. Wash hands after application. Should be used as a part of an overall lice management program.

Monitoring Parameters

Monitor scalp for lice

Pregnancy Risk Factor B Pregnancy Considerations

Adverse events were not observed in animal reproduction studies. The amount of spinosad absorbed systemically following topical administration is expected to be <3 ng/mL. Human studies did not assess the absorption of benzyl alcohol, an ingredient in the product.

Patient Education

What is this drug used for?

• It is used to treat head lice.

WARNING/CAUTION: Even though it may be rare, some people may have very bad and sometimes deadly side effects when taking a drug. Tell your doctor or get medical help right away if you have any of the following signs or symptoms that may be related to a very bad side effect:

• Eye irritation

• Skin irritation

• Signs of an allergic reaction, like rash; hives; itching; red, swollen, blistered, or peeling skin with or without fever; wheezing; tightness in the chest or throat; trouble breathing, swallowing, or talking; unusual hoarseness; or swelling of the mouth, face, lips, tongue, or throat.

Note: This is not a comprehensive list of all side effects. Talk to your doctor if you have questions.

Consumer Information Use and Disclaimer: This information should not be used to decide whether or not to take this medicine or any other medicine. Only the healthcare provider has the knowledge and training to decide which medicines are right for a specific patient. This information does not endorse any medicine as safe, effective, or approved for treating any patient or health condition. This is only a limited summary of general information about the medicine's uses from the patient education leaflet and is not intended to be comprehensive. This limited summary does NOT include all information available about the possible uses, directions, warnings, precautions, interactions, adverse effects, or risks that may apply to this medicine. This information is not intended to provide medical advice, diagnosis or treatment and does not replace information you receive from the healthcare provider. For a more detailed summary of information about the risks and benefits of using this medicine, please speak with your healthcare provider and review the entire patient education leaflet.

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.