Professional Information
Eflornithine (Topical)
VA CLASSIFICATION
Primary: DE900
Note: For a listing of dosage forms and brand names by country availability, see Dosage Forms section(s).
Category:
Enzyme inhibitor (topical) —
Indications
Accepted
Reduction of facial hair—Eflornithine hydrochloride is indicated in the reduction of unwanted facial hair in women.{01}
—Use of eflornithine should be limited to the face and adjacent involved areas under the chin. Safety and efficacy of use on other areas of the body have not been established.{01}
Pharmacology/Pharmacokinetics
Physicochemical characteristics:
Molecular weight—
236.65{01}
Mechanism of action/Effect:
Topical eflornithine hydrochloride theoretically reduces the rate of hair growth by irreversibly inhibiting the enzyme ornithine decarboxylase (ODC), an enzyme that facilitates cell division in hair follicles.{01}
Absorption:
Percutaneous absorption is less than 1% of the radioactive dose, applied either as a single or multiple dose.{01}
Biotransformation:
No metabolism of eflornithine occurs following percutaneous administration.{01}
Half-life:
Plasma, steady state—8 hours.{01}
Time to peak concentration:
Time to steady-state concentration: Within 4 days of twice-daily application.{01}
Peak plasma concentration
Steady state—10 nanograms per mL of anhydrous free base of eflornithine hydrochloride.{01}
Elimination:
Renal; unchanged.{01}
Precautions to Consider
Carcinogenicity/Tumorigenicity
An equal incidence rate of skin tumors was found in hairless albino mice treated topically with eflornithine at doses up to 600 mg per kg of body weight (mg/kg) (19 times the maximum recommended human dose [MRHD] base on body surface area [BSA]) and in untreated-control group. No evidence of carcinogenicity was found in a 2-year study in which CD-1 mice were given eflornithine in doses up to 600 mg/kg per day (950 times the MRHD based on area under the plasma concentration–time curve (AUC).{01}
Mutagenicity
Eflornithine did not show mutagenic effects in the Ames reverse-mutation assay or clastogenicity in primary human lymphocytes. In a dermal micronucleus assay, no evidence of genotoxicity was presented in rates administered eflornithine at doses up to 900 mg/kg (58 times the MRHD based on BSA).{01}
Pregnancy/Reproduction
Fertility—
A study in which rats were administered 625 mg per kg (40 times the recommended human dose) or more of eflornithine in drinking water found that fertility index values decreased.{01}No adverse effects on fertility were noted in another study which dosed rats with 450 mg per kg (29 times the recommended human dose) of eflornithine.{01}
Pregnancy—
Adequate and well-controlled studies in humans have not been done. However, in clinical trials, 19 pregnancies occurred while patients were using eflornithine. Of the 19 pregnancies, there were 9 healthy infants, 4 spontaneous abortions, 5 induced/elective abortions, and 1 case of Down's syndrome in an infant born to a 35–year-old.{01} Reduced numbers of live fetuses, decreased fetal weights, and delayed ossification and viscera development were all associated with eflornithine doses ranging from 225 to 450 mg per kg (15 and 29 times the recommended human dose) in rats. Although these doses were administered topically, no steps were taken to prevent ingestion of the drug.{01} A conflicting study, that took measures to prevent ingestion, failed to observe adverse effects on the fetus after the same dosing schedule.{01} Similarly, rabbits suffered from many adverse effects including, maternal deaths, abortions, increased fetal reabsorptions, and reduced fetal weight, when doses of 300 mg per kg per day (39 times the recommended human dose) were not combined with measures to prevent ingestion. At lower, more controllable doses of eflornithine, 90 mg per kg (11 times the recommended human dose), rabbits did not exhibit any of the previously mentioned side effects.{01}
FDA Pregnancy Category C.{01}
Breast-feeding
It is not known whether eflornithine is distributed into breast milk.{01} Problems in humans have not been documented.
Pediatrics
No information is available on the relationship of age to the effects of eflornithine in children under 12 years of age.{01} Safety and efficacy have not been established.
Geriatrics
Appropriate studies performed to date have not demonstrated geriatrics-specific problems that would limit the usefulness of eflornithine in the elderly.{01}
Medical considerations/Contraindications
The medical considerations/contraindications included have been selected on the basis of their potential clinical significance (reasons given in parentheses where appropriate)— not necessarily inclusive (» = major clinical significance).
Except under special circumstances, this medication should not be used when the following medical problems exist:
Hypersensitivity to eflornithine hydrochloride or any of its components{01}
Risk-benefit should be considered when the following medical problem exists
Broken or abraded skin{01} (transient burning or stinging may occur if applied to these areas){01}
Side/Adverse Effects
The following side/adverse effects have been selected on the basis of their potential clinical significance (possible signs and symptoms in parentheses where appropriate)—not necessarily inclusive:
Those indicating need for medical attention only if they continue or are bothersome
Incidence more frequent
Acne{01}
Stinging skin{01}
{01}
Incidence less frequent or rare
Burning or bleeding skin{01}
cheilitis {01}(chapped, red, or swollen lips)
contact dermatitis {01}
erythema {01}(skin redness)
Folliculitis {01}(hair bumps)
herpes simplex {01}
numbness {01}
tingling skin {01}
rash {01}
rosacea{01} (chronic acne)
swelling of the lips {01}
Overdose
For more information on the management of overdose or unintentional ingestion, contact a poison control center (see Poison Control Center Listing).
Treatment of overdose
Due to the low percutaneous penetration of eflornithine, it is extremely unlikely that an overdose would occur after topical administration. {01}
Supportive care—Patients in whom intentional overdose is confirmed or suspected should be referred for psychiatric evaluation.
Patient Consultation
As an aid to patient consultation, refer to Advice for the Patient, Eflornithine (Topical).
In providing consultation, consider emphasizing the following selected information (» = major clinical significance):
Before using this medication
Conditions affecting use, especially:
Hypersensitivity to eflornithine or any of its components
Proper use of this medication
Importance of reading the patient information sheet.
Using on the face and adjacent involved areas under the chin only. Avoiding getting the medication in eyes, nose, or mouth. Rinsing thoroughly with water and contacting the physician if the medicine gets in the eyes
Continuing usage of hair removal techniques with the medication. Applying the medication at least five minutes after hair removal. Applying cosmetics or sunscreen after the medication dries
» Not washing treated areas for at least 4 hours after application of medication
» Proper dosing
Using as soon as possible; not using if almost time for next dose; Do not double doses.
Proper storage
Precautions while using this medication
If skin irritation or intolerance develops, reduce the frequency of application. If irritation persists, discontinue use of the medication
If no improvement is seen after six months of treatment, discontinue usage
If condition worsens with treatment, stop usage
General Dosing Information
Note: Onset of improvement was seen after as little as 4–8 weeks of treatment in the 24–week clinical trials. Hair removal techniques should be used as needed in conjunction with the treatment of eflornithine; and eflornithine should be applied at least 5 minutes after hair removal. The condition may return to pretreatment levels 8 weeks after treatment stopped.{01}
Cosmetics or sunscreens maybe applied over treated areas after cream has dried.{01}
Topical eflornithine is used on the face and adjacent involved areas under the chin. It is for external use only. Do not apply eflornithine to abraded or broken skin; transient stinging or burning may occur.{01}
Do not wash treated areas for at least 4 hours.{01}
Topical Dosage Forms
EFLORNITHINE HYDROCHLORIDE CREAM
Usual adult and adolescent dose
Facial hair reduction
Topical, apply a thin layer of eflornithine to affected areas of the face and adjacent involved areas under the chin two times a day at least eight hours apart or as directed by a physician.{01}
Usual Pediatric Dose
Facial hair reduction
Children up to 12 years of age: Safety and efficacy have not been established.
Children 12 years of age and over: See Usual adult and adolescent dose{01}
Usual Geriatric Dose
See Usual adult and adolescent dose .
Strength(s) usually available
U.S.—
139 mg per gram (13.9%) (Rx) [Vaniqa{01} (Ceteareth–20,) ( cetearyl alcohol ) ( dimethicone) ( glyceryl stearate) ( methylparaben) ( mineral oil) ( PEG–100 stearate) ( phenoxyethanol) ( propylparaben) ( stearyl alcohol and water)]
Packaging and storage:
Store at 25 °C (77 °F), excursions permitted to 15°C–30°C (59°F–86°F). Protect from freezing{01}.
Auxiliary labeling:
• For external use only{01}.
Revised: 10/30/2000
References
- Product Information: Vaniqa™, eflornithine. Bristol–Myers Squibb Company, Princeton, NJ, (PI issued 7/2000) reviewed 10/2000.
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