Concomitant use of Pseudoephedrine, guaiphenasine & triprolidine with sympathomimetic agents such as decongestants, tricyclic antidepressants, appetite suppressants and amphetamine-like psychostimulants or with monoamine oxidase inhibitors which interfere with the catabolism of sympathomimetic amines may occasionally cause a rise in blood pressure. Because of its pseudoephedrine content, Pseudoephedrine, guaiphenasine & triprolidine partially reverse the hypotensive action of drugs which interfere with sympathetic activity including guanethidine, methyldopa, alpha-adrenergic blocking agents.