Generic Vaniqa

Pharmacodynamics

No studies have been made on examining the inhibition of the enzyme ornithine decarboxylase (ODC) in human skin by making use of topical Vaniqa Eflornithine. On the other hand, studies have been made on the inhibition of ODC activity in skin using oral eflornithine. It is assumed that this medication irrevocably inhibits skin ODC activity. This enzyme is necessary in the synthesis of polyamines. Animal data specifies that inhibition of ornithine decarboxylase holds back cell division and synthetic functions, which distress the rate of hair growth. Vaniqa Eflornithine hydrochloride Cream, 13.9% has been revealed to hinder the rate of hair growth in non-clinical and clinical studies.

Pharmacokinetics

Women using Vaniqa Eflornithine cream 13.9% for removal of unwanted facial hair absorbs showed < 1% percutaneous absorption of eflornithine of the radioactive dose, following either single or multiple doses under conditions of clinical use. This clinical trial was followed by shaving within 2 hours before radiolabeled dose usage besides other forms of cutting or plucking and tweezing to remove facial hair.

An open-label, multiple-dose study was made on ten women with excessive facial hair. They were administered two 0.5 g single doses of [14C]-labeled eflornithine HCl 13.9% (w/w) cream (periods A and C) separated by twice-daily application of 0.5 g unlabeled eflornithine HCl 13.9% cream for 7 days (period B).

Examination of radioactivity excreted in urine and feces revealed that percutaneous absorption was smallest. Comparison with urinary excretion of eflornithine in period A suggested that most of absorbed eflornithine was emitted in urine without being metabolized. Radioactivity was not found in blood or plasma, but eflornithine concentrations had peak concentrations of 4.96 ng/ml in period A and 10.44 ng/ml in period C. Eflornithine was abolished from plasma with a mean terminal half-life of 11 hours (first application) and 8 hours (final application). After 4 days of twice-daily topical treatment trough plasma concentrations was observed in a steady state (4.61-5.50 ng/ml), and multiple dosing had no clear effect on disposition kinetics. The study showed a low degree of percutaneous absorption and low systemic exposure to eflornithine. This identified Vaniqa Eflornithine HCl 13.9% cream suitable to use.

Mechanism of Action

The work of Vaniqa Eflornithine is to inhibit the enzyme ornithine decarboxylase (ODC). ODC is the rate-limiting enzyme in the biosynthesis of putrescine, spermine, and spermidine, the major polyamines in nucleated cells. Polyamines are required for the production of DNA, RNA, and proteins and are, consequently, necessary for cell growth and differentiation. While many microorganisms and higher plants can produce polyamines from alternate biochemical pathways, all mammalian cells rely on ornithine decarboxylase to generate polyamines. This medication inhibits ODC and quickly depletes animal cells of putrescine and spermidine; the concentration of spermine remains the same or may even increase. Rapidly dividing cells appear to be most susceptible to the effects of eflornithine. Topically, the inhibition of ODC in the skin results in a decreased rate of hair growth.