abametapir (Discontinued)

1-10%

Erythema (4%)

Rash (3.2%)

Scalp erythema/edema (3.2%)

Skin burning sensation (2.6%)

Vomiting (1.7%)

Contact dermatitis (1.7%)

Scalp pruritus (1.4%)

Eye irritation (1.2-1.7%)

Hair color changes (1%)

Contraindications

None

Cautions

Lotion contains benzyl alcohol; systemic exposure to benzyl alcohol has been associated with serious and fatal adverse reactions including gasping syndrome in neonates and low-birth-weight infants

Safety and effectiveness have not been established in pediatric patients aged <6 months

Use is not recommended in pediatric patients aged <6 months because of the potential for increased systemic absorption

In order to prevent accidental ingestion in pediatric patients, only administer under direct supervision of an adult

Ingestion of benzyl alcohol in large quantities may result in gastrointestinal (eg, nausea, vomiting, diarrhea) and CNS (eg, headache, ataxia, convulsions, coma) adverse reactions; serious adverse reactions may include respiratory depression and death; if accidentally swallowed, advise to call Poison Control Center at 1-800-222-1222

Drug interaction overview

• In vitro studies suggest potential for abametapir to inhibit CYP3A4, CYP2B6, and CYP1A2 enzymes following a single application
• Coadministration with substrates of these enzymes may lead to increased systemic concentrations of the interacting drugs
• Avoid administration of drugs that are substrates of CYP3A4, CYP2B6, or CYP1A2 within 2 weeks after abametapir application
• If this is not feasible, avoid abametapir use

Pregnancy

No data are available on use in pregnant females to evaluate for drug-associated risk of major birth defects, miscarriage, or adverse maternal or fetal outcomes

Animal data

• In embryofetal development studies conducted with oral administration of abametapir during organogenesis, no evidence of fetal harm or malformations, independent of maternal toxicity, were observed in pregnant rats and rabbits at doses that produced exposures up to 50 times and equivalent to the maximum recommended human dose in rats and rabbits, respectively
• Highest dose evaluated in rabbits was limited due to maternal toxicity associated with the vehicle used in the study

Lactation

No data are available regarding presence in human milk, effects on breastfed infants, or on milk production

Pregnancy Categories

A: Generally acceptable. Controlled studies in pregnant women show no evidence of fetal risk.

B: May be acceptable. Either animal studies show no risk but human studies not available or animal studies showed minor risks and human studies done and showed no risk.

C: Use with caution if benefits outweigh risks. Animal studies show risk and human studies not available or neither animal nor human studies done.

D: Use in LIFE-THREATENING emergencies when no safer drug available. Positive evidence of human fetal risk.

X: Do not use in pregnancy. Risks involved outweigh potential benefits. Safer alternatives exist.

NA: Information not available.

Mechanism of Action

• Metalloproteinase inhibitor
• Metalloproteinases have a role in physiological processes critical to egg development and survival of lice

Absorption

Peak plasma time: 0.57-1.54 hr

Peak plasma concentration

• 6 months to <1 year: 228-418 ng/mL
• 1 to <2 years: 147-209 ng/mL
• 2 to <3 years: 160-206 ng/mL
• 3 to 17 years: 52-121 ng/mL

AUC

• 6 months to <1 year: 688-1057 ng⋅hr/mL
• 1 to <2 years: 406-446 ng⋅hr/mL
• 2 to <3 years: 602-633 ng⋅hr/mL
• 3 to 17 years: 194-330 ng⋅hr/mL

Distribution

Protein bound

• Abametapir: 91.3-92.3%
• Abametapir carboxyl (metabolite): 96-97.5%

Metabolism

Extensively metabolized, primarily by CYP1A2 to a mono-hydroxylated metabolite (abametapir hydroxyl) and further to a mono-carboxylated metabolite (abametapir carboxyl)

Elimination

Excretion of abametapir and its human metabolites was not examined

Half-life (adults): 21 hr; ~71 hr or longer (abametapir carboxyl)

Topical Administration

Topical use only

Not for oral, ophthalmic, or intravaginal use

Treatment involves a single application

Shake well before use

Apply to dry hair in an amount (up to the full content of one bottle) sufficient to thoroughly coat the hair and scalp

Massage into the scalp and throughout the hair

Avoid contact with eyes

Leave on the hair and scalp for 10 min and then rinse off with warm water

Wash hands after application; shampoo hair any time after the treatment

Discard any unused product; do not flush contents down sink or toilet

Storage

Store upright at room temperature, 20-25ºC (68-77ºF); excursions permitted to 15-30ºC (59-86ºF)

Do not refrigerate or freeze