Chemistry
Lofexidine exists as a solid at room temperature, with a melting point of 127 degrees C. The pair of ortho chlorine (Cl−) atoms on the phenyl ring are necessary for lofexidines agonism at the α2a adrenergic receptor subtype; removal of either chlorine atom results in antagonism at the receptor. Comparison to clonidine
Lofexidine is structurally analogous to clonidine, another α2 adrenergic receptor agonist used for treatment of opioid withdrawal symptoms. A comparison of the two structures is shown at right. Both contain an imidazoline ring and a 2,6-dichlorinated phenyl ring. The differences in structure are shown in red, while the similarities are in black. In addition to the structural differences, administration of lofexidine to people who abuse opioids has been shown to be more effective for a longer duration, with fewer withdrawal symptoms than clonidine even after one day. However, clonidine is often preferred as it is substantially cheaper than lofexidine when purchased with a private (non-NHS) prescription. This factor is exacerbated by the considerable number of and quantities of medications prescribed to alleviate the constellation of withdrawal signs and symptoms. Additionally, clonidine has been shown to significantly lower blood pressure. Therefore, although similar to lofexidine, clonidine is most frequently prescribed to treat high blood pressure. Society and culture
Britannia Pharmaceuticals has licensed lofexidine to be sold by US WorldMeds for sale in North America. In the United Kingdom, the hydrochloride form, lofexidine HCl, has been licensed and sold since 1992 for opioid withdrawal relief in tablet form as BritLofex by Britannia Pharmaceuticals.
This indicates that the defective gene responsible for a disorder is located on an autosome (chromosomes 12 and 17 are autosomes), and only one copy of the defective gene is sufficient to cause the disorder, when inherited from a parent who has the disorder. Diagnosis
Differential diagnosis
It is often mistaken for leukoplakia.The differential diagnosis also includes hyperplastic candidiasis and frictional keratosis

Classification
The ICD-10 lists WSN under "other congenital malformations of mouth". It could be classified as a skin condition, or more precisely as a genodermatosis (a genetically determined skin disorder). Treatment
There is no treatment, but because this is a benign condition with no serious clinical complications, prognosis is excellent. See also
Oral melanosis
List of cutaneous conditions caused by mutations in keratins
Hereditary benign intraepithelial dyskeratosis

References
External links
White sponge nevus of cannon; Leukokeratosis, hereditary mucosal at NIHs Office of Rare Diseases