NATROBA

Clinical safety rating: caution

Comprehensive clinical and safety monograph for NATROBA (NATROBA).

How it works

Natroba is a pediculicide that inhibits neuronal depolarization by binding to and blocking voltage-gated sodium channels in the nervous system of lice, leading to paralysis and death of the parasite.

What the body does with it

Metabolism	Primarily metabolized by cytochrome P450 (CYP) enzymes, with minor contributions from other pathways.
Excretion	Primarily fecal (approximately 90% of absorbed dose) with minor renal elimination (<10% as unchanged drug).
Half-life	Terminal elimination half-life is approximately 10–12 hours in patients with normal hepatic function; prolonged in severe hepatic impairment.
Protein binding	≥95% bound to plasma proteins, primarily albumin.
Volume of Distribution	Approximately 1.5–2.5 L/kg, indicating extensive tissue distribution.
Bioavailability	Oral: approximately 10–15% due to extensive first-pass metabolism; topical: minimal systemic absorption (<5%).
Onset of Action	Oral: Anthelmintic effect begins within 12–24 hours after a single dose; topical: onset of lice eradication occurs within 24 hours.
Duration of Action	Oral: Single dose provides sustained scabicidal effect for 7–14 days; topical: liceicidal activity persists for up to 7 days after a single 10-minute application.

Classification & Brands

Dosing & administration

Apply a single, 10-minute application of the lotion (0.5% w/w ivermectin) to dry hair and scalp in an amount sufficient to thoroughly coat the hair and scalp (up to 1 tube for adults); rinse off with water after 10 minutes.

Dosage form	SUSPENSION
Renal impairment	No dose adjustment required; ivermectin is extensively metabolized and minimal renal excretion; safety in severe renal impairment not established.
Liver impairment	No specific Child-Pugh based adjustments; use with caution in severe hepatic impairment due to increased systemic exposure risk.
Pediatric use	Apply a single, 10-minute application of the lotion (0.5% w/w ivermectin) to dry hair and scalp in an amount sufficient to thoroughly coat the hair and scalp; for children aged 6 months and older, use up to 1 tube (60 g) as a single application.
Geriatric use	No specific dose adjustment; apply as for adults but ensure adequate coverage with caution due to potential thinner scalp skin and comorbidities.

Use during pregnancy

1st trimester	Consult provider
2nd trimester	Consult provider
3rd trimester	Consult provider

Clinical note

Comprehensive clinical and safety monograph for NATROBA (NATROBA).

Breastfeeding	Ivermectin is excreted in human milk in low concentrations. M/P ratio not specifically reported for topical formulation. After oral ivermectin, milk concentrations are approximately 2% of maternal serum. Topical application minimizes systemic absorption, but caution advised. Not recommended in nursing mothers unless clinically necessary.
Teratogenic Risk	FDA Pregnancy Category C. In animal studies, ivermectin (active ingredient in Natroba) was teratogenic at maternal toxic doses. No adequate human studies in pregnant women. Risk cannot be ruled out; use only if benefit outweighs potential fetal risk. First trimester: avoid unless essential. Second/third trimester: limited data, consider risk.

Warnings & precautions

■ FDA Black Box Warning

None.

Side Effect Profile

Serious Effects

Absolute Contraindications

["Hypersensitivity to spinosad or any component of the formulation"]

Clinical Precautions

Precautions

["Avoid contact with eyes; if contact occurs, flush with water immediately.","Do not use in patients with known hypersensitivity to spinosad or any component of the formulation.","Not for oral use; for topical application only.","Use caution in patients with broken or inflamed skin, as increased systemic absorption may occur.","Safety and efficacy in infants under 6 months of age have not been established."]

Clinical Tips & Counseling

Drug interactions

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NATROBA

Clinical safety rating: caution

Comprehensive clinical and safety monograph for NATROBA (NATROBA).

How it works

Natroba is a pediculicide that inhibits neuronal depolarization by binding to and blocking voltage-gated sodium channels in the nervous system of lice, leading to paralysis and death of the parasite.

What the body does with it

Metabolism	Primarily metabolized by cytochrome P450 (CYP) enzymes, with minor contributions from other pathways.
Excretion	Primarily fecal (approximately 90% of absorbed dose) with minor renal elimination (<10% as unchanged drug).
Half-life	Terminal elimination half-life is approximately 10–12 hours in patients with normal hepatic function; prolonged in severe hepatic impairment.
Protein binding	≥95% bound to plasma proteins, primarily albumin.
Volume of Distribution	Approximately 1.5–2.5 L/kg, indicating extensive tissue distribution.
Bioavailability	Oral: approximately 10–15% due to extensive first-pass metabolism; topical: minimal systemic absorption (<5%).
Onset of Action	Oral: Anthelmintic effect begins within 12–24 hours after a single dose; topical: onset of lice eradication occurs within 24 hours.
Duration of Action	Oral: Single dose provides sustained scabicidal effect for 7–14 days; topical: liceicidal activity persists for up to 7 days after a single 10-minute application.

Classification & Brands

Dosing & administration

Dosage form	SUSPENSION
Renal impairment	No dose adjustment required; ivermectin is extensively metabolized and minimal renal excretion; safety in severe renal impairment not established.
Liver impairment	No specific Child-Pugh based adjustments; use with caution in severe hepatic impairment due to increased systemic exposure risk.
Pediatric use	Apply a single, 10-minute application of the lotion (0.5% w/w ivermectin) to dry hair and scalp in an amount sufficient to thoroughly coat the hair and scalp; for children aged 6 months and older, use up to 1 tube (60 g) as a single application.
Geriatric use	No specific dose adjustment; apply as for adults but ensure adequate coverage with caution due to potential thinner scalp skin and comorbidities.

Use during pregnancy

1st trimester	Consult provider
2nd trimester	Consult provider
3rd trimester	Consult provider

Clinical note

Comprehensive clinical and safety monograph for NATROBA (NATROBA).

Breastfeeding	Ivermectin is excreted in human milk in low concentrations. M/P ratio not specifically reported for topical formulation. After oral ivermectin, milk concentrations are approximately 2% of maternal serum. Topical application minimizes systemic absorption, but caution advised. Not recommended in nursing mothers unless clinically necessary.
Teratogenic Risk	FDA Pregnancy Category C. In animal studies, ivermectin (active ingredient in Natroba) was teratogenic at maternal toxic doses. No adequate human studies in pregnant women. Risk cannot be ruled out; use only if benefit outweighs potential fetal risk. First trimester: avoid unless essential. Second/third trimester: limited data, consider risk.

Warnings & precautions

■ FDA Black Box Warning

None.

Side Effect Profile

Serious Effects

Absolute Contraindications

["Hypersensitivity to spinosad or any component of the formulation"]

Clinical Precautions

Precautions

Clinical Tips & Counseling

Drug interactions

Loading safety data…