<prompt> Which of the following H1 blocker has high anticholinergic activityCetirizineChlorpheneramineFexofenadineAstemizole  <response>: Cetirizine and fexofenadine did not antagonize cholinergic responses. Chlorphenamine, also known as chlorpheniramine, is an antihistamine used to treat the symptoms of allergic conditions such as allergic rhinitis. It is taken by mouth. Onset is within 6 hours and effects last for about a day. Refer kDT 7e p164 