Amlexanox

Amlexanox is the active ingredient in a common topical treatment for recurrent aphthous ulcers of the mouth (canker sores),^[2] reducing both healing time^[3] and pain.^[4] Amlexanox 5% paste is well tolerated,^[5] and is typically applied four times per day directly on the ulcers.^[3] A 2011 review found it to be the most effective treatment of the eight treatments investigated for recurrent canker sores.^[6] It is also used to treat ulcers associated with Behçet disease.^[7]

In Japan, it is used to treat bronchial asthma, allergic rhinitis and conjunctivitis.^[8]

The drug is contraindicated in those with known allergies to it.^[3]

Amlexanox may cause a slightly painful stinging or burning sensation, nausea or diarrhea.^[3]

Its mechanism of action is not well-determined, but it might inhibit inflammation by inhibiting the release of histamine and leukotrienes.^[8] It has been shown to selectively inhibit TBK1 and IKK-ε, producing reversible weight loss and improved insulin sensitivity, reduced inflammation and attenuated hepatic steatosis without affecting food intake in obese mice.^[9] It produced a statistically significant reduction in glycated hemoglobin and fructosamine in obese patients with type 2 diabetes and nonalcoholic fatty liver disease^[10]

The chemical itself is an odorless, white to yellowish-white powder.^[8]

The 5% preparation for patient use is an adherent beige paste,^[3][8] and it is also available in some countries as a tablet that adheres to the ulcer in the mouth.^[4]

Amlexanox applied to an aphthous ulcer is largely absorbed through the gastrointestinal tract; an insignificant amount enters the bloodstream through the ulcer itself. After a single 100 mg dose, mean maximum serum concentration occurs 2.4 +/- 0.9 hours after application, with a half-life of elimination (through urine) of 3.5 +/- 1.1 hours. With multiple daily applications (four doses per day), steady state serum levels occur after one week, with no accumulation occurring after four weeks.^[8]

The patent for its use as a treatment for aphthous ulcers was issued in November 1994 to inventors Kakubhai R. Vora, Atul Khandwala and Charles G. Smith, and assigned to Chemex Pharmaceuticals, Inc.^[11]

A review found that, as of July 2011^[update], robust studies investigating its effectiveness alongside other canker sore treatments were still needed.^[12]

Because it is an inhibitor of the protein kinases TBK1 and IKK-ε,^[9] which are implicated in the etiology of type II diabetes and obesity,^[13] amlexanox may be a candidate for human clinical trials testing in relation to these diseases.^[9]