Pharmacodynamics<unk>  is a selective peripheral H1 receptor antagonist. Blockage prevents the activation of the H1 receptors by histamine, preventing the symptoms associated with allergies from occurring.<unk>  does not readily cross the blood–brain barrier, so is less likely to cause drowsiness in comparison to other antihistamines that readily cross that barrier (i.e. first-generation antihistamines such as diphenhydramine). In general,<unk>  takes about an hour to take effect, though this may be affected by the choice of dosage form and the presence of certain foods.<unk>  also exhibits no anticholinergic, antidopaminergic, alpha 1-adrenergic, or beta-adrenergic receptor-blocking effects. Pharmacokinetics * Absorption: After oral application, maximum plasma concentrations are reached after 2–3 hours.<unk>  should not be taken with a high-fat meal, as mean concentrations of<unk>  in the bloodstream are seen to be reduced from 20–60% depending on form of medication (tablet, ODT, or suspension). * Distribution:<unk>  is 60–70% bound to plasma proteins, mostly albumin. * Metabolism:<unk>  is a substrate of CYP3A4, but only about 5% is metabolized by the liver, indicating that hepatic metabolism is relatively minor in clearance from the body. * Elimination: Most of the substance is eliminated unchanged via the feces (80%) and urine (11–12%).
Fexofenadine
Ecallantide
Cetirizine
Terfenadine
Anakinra
Budesonide
Mibolerone
Ciclopirox