Triprolidine should be used cautiously in patients with asthma, bronchitis, chronic obstructive pulmonary disease (COPD), or emphysema. Thickened bronchial secretions that aggravate these conditions my result from the anticholinergic activity of H1-antagonists. Triprolidine use may be possible in patients with these illnesses, particularly if thick bronchial secretions are not a primary component of the illness.