Amlexanox (trade name Aphthasol) is an anti-inflammatory

antiallergic An allergen is a type of antigen that produces an abnormally vigorous immune response in which the immune system fights off a perceived threat that would otherwise be harmless to the body. Such reactions are called allergies. In technical terms ...

immunomodulator used to treat recurrent aphthous ulcers (canker sores), and (in Japan) several inflammatory conditions. This drug has been discontinued in the U.S.

Medical uses

Amlexanox is the active ingredient in a common topical treatment for recurrent

aphthous ulcers Aphthous stomatitis, or recurrent aphthous stomatitis (RAS), is a common condition characterized by the repeated formation of benign and non-contagious mouth ulcers (aphthae) in otherwise healthy individuals. The informal term ''canker sore'' i ...

of the mouth (canker sores), reducing both healing time and pain. Amlexanox 5% paste is well tolerated, and is typically applied four times per day directly on the ulcers. A 2011 review found it to be the most effective treatment of the eight treatments investigated for recurrent canker sores. It is also used to treat ulcers associated with

Behçet disease Behçet is a Turkish name and may refer to: Given name * Behçet Cantürk, Turkish mob boss * Behçet Necatigil, Turkish author and poet * Behçet Uz, Turkish politician and doctor Surname * Hulusi Behçet, Turkish dermatologist and scientist Ot ...

. In Japan, it is used to treat

bronchial asthma Asthma is a long-term inflammatory disease of the airways of the lungs. It is characterized by variable and recurring symptoms, reversible airflow obstruction, and easily triggered bronchospasms. Symptoms include episodes of wheezing, coug ...

, allergic rhinitis and

conjunctivitis Conjunctivitis, also known as pink eye, is inflammation of the conjunctiva, outermost layer of the white part of the eye and the inner surface of the eyelid. It makes the eye appear pink or reddish. Pain, burning, scratchiness, or itchiness may ...

Contraindications

The drug is contraindicated in those with known allergies to it.

Adverse effects

Amlexanox may cause a slightly painful stinging or burning sensation, nausea or diarrhea.

Mechanism of action

Its mechanism of action is not well-determined, but it might inhibit inflammation by inhibiting the release of

histamine Histamine is an organic nitrogenous compound involved in local immune responses, as well as regulating physiological functions in the gut and acting as a neurotransmitter for the brain, spinal cord, and uterus. Since histamine was discovered in ...

and leukotrienes. 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. It produced a statistically significant reduction in

glycated hemoglobin Glycated hemoglobin, also known as HbA1c, glycohemoglobin, hemoglobin A1c, A1C, is a form of hemoglobin (Hb) that is chemically linked to a sugar. Most monosaccharides, including glucose, galactose and fructose, spontaneously (i.e. non-enzymatic ...

and

fructosamine Fructosamines are compounds that result from glycation reactions between a sugar (such as fructose or glucose) and a primary amine, followed by isomerization via the Amadori rearrangement. Biologically, fructosamines are recognized by fructosamin ...

in obese patients with

type 2 diabetes Type 2 diabetes, formerly known as adult-onset diabetes, is a form of diabetes mellitus that is characterized by high blood sugar, insulin resistance, and relative lack of insulin. Common symptoms include increased thirst, frequent urination, ...

and

nonalcoholic fatty liver disease Non-alcoholic fatty liver disease (NAFLD), also known as metabolic (dysfunction) associated fatty liver disease (MAFLD), is excessive fat build-up in the liver without another clear cause such as alcohol use. There are two types; non-alcoholic f ...

Chemistry

The chemical itself is an odorless, white to yellowish-white powder. The 5% preparation for patient use is an adherent beige paste, and it is also available in some countries as a tablet that adheres to the ulcer in the mouth.

Pharmacokinetics

Amlexanox applied to an aphthous ulcer is largely absorbed through the

gastrointestinal tract The gastrointestinal tract (GI tract, digestive tract, alimentary canal) is the tract or passageway of the digestive system that leads from the mouth to the anus. The GI tract contains all the major organ (biology), organs of the digestive syste ...

; 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.

History

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.

Society and culture

Economics

A 2011 review found a one-week supply of amlexanox 5% paste to cost $30.

Research

A review found that, , robust studies investigating its effectiveness alongside other canker sore treatments were still needed. Because it is an

inhibitor Inhibitor or inhibition may refer to: In biology * Enzyme inhibitor, a substance that binds to an enzyme and decreases the enzyme's activity * Reuptake inhibitor, a substance that increases neurotransmission by blocking the reuptake of a neurotra ...

of the protein kinases TBK1 and IKK-ε, which are implicated in the

etiology Etiology (pronounced ; alternatively: aetiology or ætiology) is the study of causation or origination. The word is derived from the Greek (''aitiología'') "giving a reason for" (, ''aitía'', "cause"); and ('' -logía''). More completely, e ...

type II diabetes Type 2 diabetes, formerly known as adult-onset diabetes, is a form of diabetes mellitus that is characterized by high blood sugar, insulin resistance, and relative lack of insulin. Common symptoms include increased thirst, frequent urination, ...

and

obesity Obesity is a medical condition, sometimes considered a disease, in which excess body fat has accumulated to such an extent that it may negatively affect health. People are classified as obese when their body mass index (BMI)—a person's we ...

, amlexanox may be a candidate for human clinical trials testing in relation to these diseases.

Synthesis

References

{{Drugs for obstructive airway diseases Anti-inflammatory agents Leukotriene antagonists Carboxylic acids Isopropyl compounds