eflornithine

Action and Spectrum

Actions and Spectrum:  

Actions:  

Eflornithine acts through the inhibition of the ornithine decarboxylase enzyme that is crucial to hair growth. Eflornithine interferes with this enzyme’s function, thereby making it difficult for hair to grow; there will be limited formation of hair cells.

Eflornithine is being effective only in treatment of hirsutism. It is not used in treating other conditions. 

Drug Interaction

Adverse Reaction

Frequency defined   

1-10%  

Seizures (8%)  

Diarrhea  

Vomiting   

Hearing impairment  

Dizziness  

Eosinophilia  

Alopecia  

<1%  

Weakness  

Abdominal pain  

Headache  

Facial edema  

Anorexia  

>10%  

Leukopenia (37%)  

Thrombocytopenia (14%)  

Anemia (55%) 

Black Box Warning

Black Box Warning  

None  

Contraindication / Caution

Contraindication/Caution:  

Contraindication:  

Allergy to eflornithine cream 

Caution  

Only for external use 

History of skin allergy and sensitivity 

Pregnancy and lactation 

Pregnancy / Lactation

Pregnancy & breastfeeding: 

Pregnancy category: C   

Lactation: No data is available regarding the excretion of drugs in breast milk.  

Pregnancy category:  

Category A: well-controlled and satisfactory studies show no risk to the fetus in the first or later trimester.  

Category B: There was no evidence of risk to the fetus in animal studies, and there were not enough studies on pregnant women.  

 Category C: There was evidence of risk of adverse effects in animal reproduction studies, and no adequate evidence in human studies must take care of potential risks in pregnant women.   

 Category D: Adequate data with sufficient evidence of human fetal risk from various platforms, but despite the potential risk, and used only in emergency cases for potential benefits.   

Category X: Drugs listed in this category outweigh the risks over benefits. Hence, these categories of drugs need to be avoided by pregnant women.  

Category N: No data for the drug under this category is available.  

Pharmacology

Pharmacology:  

The overall action of eflornithine is to inhibit the activity of the ornithine decarboxylase enzyme, which is essential for the formation of polyamines, since hair cells and other cells require polyamines, eflornithine works by reducing the rate of hair growth through the inhibition of ornithine decarboxylase in hair follicles cells and changing their rate of division. 

Pharmacodynamics:  

Eflornithine is effective and safe in the treatment of hirsutism since it has selective effect on hair growth and has no side effects on other cell types. It does not contact with the body androgens or hormones consequently and has no hormonal impacts.
 

Pharmacokinetics:  

Absorption 

Clinical data revealed that less than 2% of the eflornithine was systemically absorbed through the skin. 

Since the liver goes through first-pass metabolism and metabolizes a huge amount of the drug, eflornithine has a poor bioavailability. 

Distribution 

In the treated area, eflornithine deposits primarily in the skin and the hair follicle. 

It does not cross the blood-brain barrier and is, therefore, not deposited in the organs, specifically the brain. 

Metabolism 

Eflornithine is a major substrate of the liver’s ornithine decarboxylase enzyme to a greater extent. 

The primary metabolite responsible for the pharmacological effects of eflornithine is difluoromethylornithine. 

Excretion and elimination 

Most of the eflornithine and its metabolites are found to be cleared out from the body through urine while a minimal amount is expelled through feces. 

The half-life of the drug is eight hours. 

Adminstartion

Administration:  

The drug is administered topically. 

Patient Information Leaflet

Patient information leaflet  

Generic Name: eflornithine 

Why do we use eflornithine?  

Eflornithine was developed for the management of hirsutism, a condition in which women experience hair growth in certain areas of the body, such as the face or thighs, normally linked to male-pattern hair growth.
The prescribed medication inhibits the growth of hair on the treated area of skin thereby reducing the visibility of hair.