ivermectin topical (Rx, OTC)

<1%

Conjunctivitis

Ocular hyperemia

Eye irritation

Dandruff

Dry skin

Skin burning sensation

Postmarketing Reports

Local adverse reactions: Contact dermatitis and allergic dermatitis

Contraindications

None

Cautions

To prevent ingestion, administer to children only with direct adult supervision

Not for oral, ophthalmic, or intravaginal use

Avoid contact with lips or eyes; wash hands following application

Topical lotion is for use on scalp and scalp hair only

Systemic absorption and potential for toxicity in infants <6 months may be increased due to higher surface area to body mass ration and immature skin barrier; not recommended for these patients

Pregnancy

There are no studies with use of in pregnant females

Insufficient data available on oral use to inform a drug-associated risk of adverse developmental outcomes, because either the timing of administration during gestation was not accurately ascertained or the administration occurred only during the second trimester

However, systemic exposure from topical use of ivermectin is much lower than that from oral use

Animal data

• Ivermectin induced adverse developmental outcomes when orally administered to pregnant mice, rats and rabbits during organogenesis only at or near doses that were maternally toxic to the pregnant females

Lactation

There is information available on the presence of ivermectin in human milk in 4 lactating women after a single 150 mcg/kg oral dose of ivermectin

However, there is insufficient information to determine the effects of ivermectin on the breastfed infant or the effects of ivermectin on milk production

Topical ivermectin systemic exposure is much lower than that for oral ivermectin

Furthermore, the amount of ivermectin present in human milk after topical application of ivermectin to lactating women has not been studied

Clinical considerations

• Advise a lactating woman to avoid accidental transfer of topical ivermectin to breast area where the infant might directly ingest the drug

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

Pediculicide derived from fermentation of a soil dwelling actinomycete, Streptomyces avermitilis

Causes parasite death by selective, high-affinity binding to glutamate-gated chloride channels located in invertebrate nerve and muscle cells; this results in increased cell membrane permeability to chloride ions with hyperpolarization of the nerve or muscle cells, and ultimately parasite paralysis and death

The mechanism by which ivermectin topical treats rosacea lesions is unknown

Absorption

Plasma levels following topical administration are much lower than those observed following PO administration

Peak plasma concentration: 0.24 ng/mL (topical); 30.6-46.6 ng/mL (PO)

AUC: 6.7 hr•ng/mL

Topical Administration

General instructions for lice

• Use lotion in context of an overall lice management program including hot-water washing or dry-cleaning of all recently worn clothing and linens
• Wash personal care items (eg, combs, brushes, hair clips)
• A fine tooth comb or nit comb may be used to remove dead lice and nits

Topical lotion

• For topical use only
• Avoid contact with eyes
• Inspect affected area by using magnifying glass in bright light to see lice and/or nits (eggs)
• Examine small sections of hair (1-2 inches wide) at a time
• Hair and scalp must be dry before applying product
• Apply product directly to dry hair and scalp
• Completely cover scalp and hair closest to scalp first, and then apply outwards towards ends of hair
• Use only amount needed to completely cover hair and scalp, up to 1 entire tube, and discard remaining
• Rub product throughout hair; completely cover entire head so that all lice and eggs are exposed to lotion
• Wait and rinse; allow product to stay on hair and scalp for 10 minutes after application
• Start timing after hair and scalp are completely covered with product
• After 10 minutes, rinse product completely from hair and scalp using only water
• After rinsing, dry and style as usual
• Wait 24 hours before applying shampoo
• Wash hands after applying product
• This is a single use product; discard tube after use
• Do not use again on same person and same lice infestation without talking to healthcare provider first; if infestation continues, see a doctor for other treatments
• After finishing treatment, check for lice after 1 week; consider treatment for those who have lice

Topical cream

• Apply cream to face, squeeze a pea-sized amount of cream from tube onto fingertip
• Apply to the affected areas of face once a day
• Use a pea-sized amount of cream for each area of face (forehead, chin, nose, each cheek) that is affected
• Spread cream smoothly and evenly in a thin layer
• Avoid contact with eyes and lips

Storage

Keep out of reach of children

Topical lotion

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

Topical cream

• Store at room temperature 20-25ºC (68-77ºF)