ENGOV

Mepyramine is a first generation antihistamine, targeting the H1 receptor. However, it rapidly permeates the brain and so often causes drowsiness as a side effect. Mepyramine is a histamine H1 receptor inverse agonist. It binds to a G protein-coupled form of the receptor and promotes a G protein-coupled inactive state of the H1 receptor that interferes with the Gq/11-mediated signaling. Mepyramine competes with histamine for binding at H1-receptor sites on the effector cell surface, resulting in suppression of histaminic edema, flare, and pruritus. The sedative properties of mepyramine occur at the subcortical level of the CNS. It has mild hypnotic properties and some local anesthetic action and is used for allergies (including skin eruptions) both parenterally and locally. It is a common ingredient of cold remedies.

Aluminium hydroxide is a slow-acting antacid. It is used to provide symptomatic relief in gastric hyperacidity. In addition, the antipeptic and demulcent activity of aluminium hydroxide helps to protect inflamed gastric mucosa against further irritation by gastric secretions.

Acetylsalicylic acid combines significant advantages such as strong anti-pyretic, analgesic and anti-inflammatory action, that is the measure of comparison with all the newer NSAIDs.

Caffeine is structurally related to the methylxanthines theophylline and theobromine. Caffeine’s main action is as a CNS stimulant.