Although patients receiving systemic corticosteroid therapy are more susceptible to secondary infection than patients not receiving corticosteroids, administration via the inhaled route minimizes this risk. Corticosteroid therapy can mask the symptoms of infection and should not be used in cases of bacterial, fungal, or viral infections that are not adequately controlled by anti-infective agents, except in life-threatening circumstances. Fluticasone; salmeterol should be avoided in patients with tuberculosis infections of the respiratory tract if possible. The incidence or course of acute bacterial or viral infection is probably minimally affected by inhaled corticosteroids in immunocompetent individuals; however, close monitoring of patients with immunosuppression is recommended if treatment with an inhaled corticosteroid is necessary.
Children and adolescents <16 years taking high doses of fluticasone propionate (typically ≥1000 micrograms/day) may be at particular risk of systemic effects. Systemic effects may occur, particularly at high doses prescribed for long periods. Possible systemic effects include Cushing's syndrome, Cushingoid features, adrenal suppression, acute adrenal crisis and growth retardation in children and adolescents and more rarely, a range of psychological or behavioural effects including psychomotor hyperactivity, sleep disorders, anxiety, depression or aggression. Consideration should be given to referring the child or adolescent to a paediatric respiratory specialist.
Histamine is a chemical that is responsible for many of the signs and symptoms of allergic reactions, for example, swelling of the lining of the nose, sneezing , and itchy eyes. Histamine is released from histamine-storing cells (mast cells) and then attaches to other cells that have receptors for histamine. The attachment of the histamine to the receptors causes the cells to be "activated," releasing other chemicals that produce the effects that we associate with allergy (for example, sneezing ). Fexofenadine blocks one type of receptor for histamine (the H1 receptor) and thus prevents activation of H1 receptor-containing cells by histamine. Unlike the first generation antihistamines, fexofenadine and other second-generation antihistamines do not readily enter the brain from the blood. Therefore, they cause less drowsiness and are called non-sedating antihistamines. Fexofenadine was approved by the FDA in July 1995.