Impaired renal & hepatic impairment. Montelukast: Eosinophilic conditions. Avoid aspirin or NSAIDs in patients w/ known aspirin sensitivity. Neuropsychiatric events in adults, adolescents, & childn. Levocetirizine: Patients w/ predisposing factors of urinary retention (eg, spinal cord lesion, prostatic hyperplasia). Patients w/ epilepsy & those w/ risk of convulsion. A wash-out period of 3 days is required before performing allergy skin tests. Pruritus may occur. Avoid concurrent use of alcohol.