Inhibits response to allergy skin tests; a wash-out period (of 3 days) is required before the test. Rare hereditary problems of galactose intolerance, Lapp lactase deficiency or glucose-galactose malabsorption; contains lactose monohydrate. Concurrent intake of alcohol. Pregnancy & lactation. Not recommended in childn <6 yr; use a paed formulation of levocetirizine. Levocetirizine: Patients w/ predisposing factors of urinary retention (eg, spinal cord lesion, prostatic hyperplasia); epilepsy & patients at risk of convulsion. Pruritus. Montelukast: Never use oral dosage form to treat acute asthma attacks. Use a short-acting inhaled β-agonist if an acute attack occurs. Do not substitute abruptly for inhaled or oral corticosteroids. Do not alter treatment w/ the need for patients w/ aspirin-sensitive asthma to avoid taking aspirin & other NSAIDs. Neuropsychiatric events in adults, adolescents, & childn.