May cause CNS depression, which may impair physical or mental abilities. Concurrent use with psychotropics may produce additive sedation. Use with caution in history of asthma, cardiovascular disease (including hypertension and ischemic heart disease), increased intraocular pressure, prostatic hyperplasia and/or genitourinary obstruction, pyloroduodenal obstruction (including stenotic peptic ulcer) or thyroid dysfunction. Effects may be potentiated when used with other sedative drugs or ethanol. Use with caution in the elderly (may be more sensitive to adverse effects). Antihistamines may cause paradoxal excitation in young children.