House dust mite extracts consists mainly of polypeptides and proteins that are not subject to liver metabolism or interaction with CYP enzymes.

Allergen extract, house dust mite. Contains polypeptides and proteins.

Allergen extracts containing house dust mite are used in allergy immunotherapy, to desensitize people that have an allergy to house dust mite. It is administered as a sublingual tablet (sublingual immunotherapy, SLIT). It may be used continuously for up to 3 years for long term efficacy (SPC).

Upon sublingual administration allergen is presumably taken up by dendritic cells of the oral mucosa and presented to other cells of the immune system. The allergen molecules not taken up by antigen-presenting cells are believed to undergo enzymatic hydrolysis during passage through the gastrointestinal tract. There is no evidence suggesting that intact allergen enters the systemic circulation after sublingual administration and there are no reports that SLIT affects renal or hepatic function (Canonica 2016). No pharmacokinetic studies in animals or clinical studies have been conducted (EMEA, SPC).