Allergy Agents

These flashcards cover key vocabulary related to allergy agents, including histamines, antihistamines, and associated clinical considerations.

Histamines

Chemical mediators in immune and inflammation responses, found in most body tissues.

H1 receptor

A receptor associated with the allergic response.

Mast cells

Cells that synthesize and store histamines, released during immediate hypersensitivity reactions and cellular injury.

Edema

Increased permeability of capillaries caused by H1 receptor stimulation.

Antihistamines

Drugs that compete for H1 receptor sites, decreasing the allergic response.

First Generation Antihistamines

Includes diphenhydramine and chlorpheniramine, which are associated with higher sedation.

Second Generation Antihistamines

Examples include fexofenadine and loratadine, preferred for allergies due to non-sedating properties and once daily dosing.

Intranasal corticosteroids

Medications that inhibit inflammatory cytokine release and block hypersensitivity responses.

Cromolyn

A mast cell stabilizer used for allergic rhinitis that prevents the release of broncho-constrictive substances.

Adverse Effects of Antihistamines

Can include sedation, anticholinergic effects, such as dry mouth and urinary retention.

Nursing Considerations for Antihistamines

Monitor for increased sedation and advise against driving while sedated.

Epistaxis

A potential adverse effect of intranasal corticosteroids, indicating a nosebleed.

Vasoconstriction

A reaction can happen during H1 receptor stimulation affecting smooth muscle.