Eflornithine – Uses

Background

Eflornithine is a prescription drug indicated in the treatment of facial hirsutism (excessive hair growth). Eflornithine hydrochloride cream for topical application is intended for use in women suffering from facial hirsutism and is sold by Allergan, Inc. under the brand name Vaniqa. Eflornithine for injection against sleeping sickness was manufactured by Sanofi Aventis and sold under the brand name Ornidyl in the USA. It is now discontinued. Eflornithine is on the World Health Organization’s List of Essential Medicines.

Properties and Characteristics of Eflornithine

Drug class	Antiprotozoal
Brand Names	Vaniqa
Synonyms	alpha-difluoromethylornithine, DFMO, Eflornithine
Molecular Formula	C6H12F2N2O2
Molecular Weight	182.17 g/mol
IUPAC Names	2,5-diamino-2-(difluoromethyl)pentanoic acid
Structural formula of main components
Pure active ingredient	Eflornithine hydrochloride
Appearance	White to Off-White Solid
Melting Point	>210°C
Solubility	In water, 5.5X10+5 mg/L at 25 °C (est)
Excretion	Excreted unchanged in urine
Available as	Cream
Storage	Store at room temperature between 15 and 30 degrees C (59 and 86 degrees F).
Prescription	Prescription is required

What is eflornithine used for?

Eflornithine HCl cream is indicated for the reduction of unwanted facial hair in women. Over 20 million American women in the United States have excessive facial hair caused by the following factors:

• Genetic – hirsutism or hypertrichosis
• Menopause and the normal aging process
• Medical condition such as androgen excess disorder and polycystic ovarian syndrome
• Medications

Women with excessive facial hair often experience low self-esteem and embarrassment. Eflornithine HCl cream slows the rate of hair growth and is often used in combination with other hair removal techniques to maintain a hair-free complexion.

Eflornithine topical side effects

Get emergency medical help if you have signs of an allergic reaction: hives; difficult breathing; swelling of your face, lips, tongue, or throat.

Eflornithine may cause serious side effects. Stop using eflornithine and call your doctor at once if you have:

• Severe irritation of treated skin; or
• Redness or crusting around your hair follicles.

Common side effects of eflornithine topical may include:

• Temporary redness, rash, burning, stinging, itching, or tingling;
• Acne or red bumps on the skin;
• Skin dryness; or
• Headache.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects.

Mechanism of action

Eflornithine prevents hair growth by inhibiting the anagen phase of hair production. This occurs by eflornithine irreversibly binding (also called suicide inhibition) to ornithine decarboxylase (ODC) and physically preventing the natural substrate ornithine from accessing the active site.

Eflornithine interaction with other drugs

Eflornithine (Vaniqa) may interact with certain medications or supplements. Always let your doctor and pharmacist know about any other medications or supplements (including prescribed and over-the-counter medications, vitamins, and dietary or herbal supplements) that you are currently taking.

Although certain medicines should not be used together at all, in other cases two different medicines may be used together even if an interaction might occur. In these cases, your doctor may want to change the dose, or other precautions may be necessary. Tell your healthcare professional if you are taking any other prescription or nonprescription (over-the-counter [OTC]) medicine.

Dosing

The dose of this medicine will be different for different patients. Follow your doctor’s orders or the directions on the label. The following information includes only the average doses of this medicine. If your dose is different, do not change it unless your doctor tells you to do so.

The amount of medicine that you take depends on the strength of the medicine. Also, the number of doses you take each day, the time allowed between doses, and the length of time you take the medicine depend on the medical problem for which you are using the medicine.

For topical dosage form (cream):

For reduced rate of facial hair growth in women.

• Adults and children 12 years of age or older—Coat the problem areas on the face and nearby areas under the chin with the medicine two times a day with the second treatment coming at least eight hours after the first.
• Children under 12 years of age—Use and dose must be determined by your doctor.

Overdose

Overdosage information with Eflornithine is unavailable. Given the low percutaneous penetration of this drug, overdosage via the topical route is not expected. However, should very high topical doses (e.g., multiple tubes per day) or oral ingestion be encountered (a 30 g tube contains 4.2 g of eflornithine hydrochloride), the patient should be monitored, and appropriate supportive measures administered as necessary. (Note: Use of an intravenous formulation of eflornithine hydrochloride at high doses (400 mg/kg/day or approximately 24 g/day) for the treatment of Trypanosoma brucei gambiense infection (African sleeping sickness) has been associated with adverse events and laboratory abnormalities. Adverse events in this setting have included hair loss, facial swelling, seizures, hearing impairment, stomach upset, loss of appetite, headache, weakness and dizziness. A variety of hematological toxicities, including anemia, thrombocytopenia and leukopenia have also been observed, but these were usually reversible upon discontinuation of treatment.)

Warnings before consuming eflornithine

Warnings for special population

Pregnancy: Eflornithine is not recommended for use in pregnancy unless necessary. If you are pregnant, consult your doctor before using this medicine.

Breast-feeding: Eflornithine is not recommended for use in breastfeeding unless necessary. If you are breastfeeding, consult your doctor before using this medicine.

General warnings

Other medicines: Eflornithine may interact with certain medicines and cause side effects. Hence, it is advised to inform the doctor about all your current medicines, including any herbs and supplements, before beginning treatment with this medicine.

External use only: Eflornithine is recommended for external use only. Avoid contact with your eyes, mouth, mucous membranes, or open wounds. Rinse with water in the case of accidental contact with these areas.

Use in children: Eflornithine is not recommended for use in children less than 12 years of age as the safety and efficacy data are not available.