Patients w/ predisposing factors of urinary retention eg, spinal cord lesion, prostatic hyperplasia. Consider 3-day wash-out period before performing allergy skin tests. Not to be taken by patients w/ galactose intolerance, Lapp lactase deficiency or glucose-galactose malabsorption. Concurrent use w/ alcohol. May affect ability to drive & use machines. Moderate to severe renal impairment. Pregnancy & lactation. Not recommended in childn <6 yr. Elderly.