How does Zyrtec-D interact with other medications or food?

Cetirizine and pseudoephedrine have a negative interaction with MAO inhibitor drugs such as isocarboxazid, phenelzine, rasagiline, selegiline, or tranylcypromine. Do not take the medication if you have used an MAO inhibitor drug within the previous two weeks. Other medications that may cause a negative interaction with cetirizine and pseudoephedrine include ephedrine, methylphenidate, methyldopa, guanethidine, reserpine, propranolol, some anti-anxiety drugs, antihistamines that cause drowsiness, anti-seizure medications, sleep medications, tranquilizers, muscle relaxants, narcotic pain relievers, and some psychiatric drugs. Many over-the-counter cold medications contain pseudoephedrine. Using these medications along with cetirizine and pseudoephedrine can cause an overdose of the latter medication. Cetirizine and pseudoephedrine do not have any known interactions with food.