Zyrtec PI Page 1 of 8 Australia _____ J&J Pacific 3rd April 2014 1 of 8 Doctors give trusted answers on uses, effects, side-effects, and cautions: Dr. Khanna on benadryl zyrtec interaction: May not be a good idea. What are your symptoms sometimes a doctor may add steroids and other instructions to control severe allergic Rhinitis If your dog has allergies, you may have looked into giving him Apoquel to ease his symptoms. Discover side effects of Apoquel for dogs here! It is pretty obvious that Zyrtec for pet allergies is very feasible and beneficial for dogs as it is effective in relieving the frustrating symptoms of allergies. I started taking Zyrtec for seasonal allergies. After a month on this drug, I noticed a lump on my forehead. I initially dismissed it as acne. But it grew rapidly. Zyrtec is the brand name of cetirizine, an over-the-counter (OTC) antihistamine used to treat cold and allergy symptoms such as sneezing, itching, watery eyes, or runny nose. Yes, it is okay to use these two medications together. You should be aware that a moderate drug interaction can occur because both of these medications will depress your central nervous system. If you have an interaction, it will most likely cause reduced alertness, asthenia, or sleepiness. How to use Zyrtec. If you are taking the over-the-counter product to self-treat, read all directions on the product package before taking this medication. Zyrtec for Dogs: Each season has its pros and cons, but if you suffer from allergies, spring is probably your worst season. Sadly, our four-legged friends tend to get hit by allergies worse than we do. To combat these symptoms, humans and dogs alike turn to a common allergy medication: Zyrtec. Zyrtec is a human antihistamine medication that may be used for the treatment of mild to moderate itching associated with allergies in cats. Learn more about the use of Zyrtec in cats.