Benadryl can cause mild or serious side effects. The following list contains some of the key side effects that may occur while taking Benadryl. Zyrtec can be a good antihistamine for allergies and hives though it can cause sedation and fatigue in some people. These symptoms are usually milder than with the first generation antihistamines, but more pronounced than with medications such as Claritin or Allegra. The common cold will usually run its course within 7 to 14 days. There are many natural remedies and over the counter products that are compatible with breastfeeding. Symptoms Treated Runny Nose Headache Sinus Pressure/Congestion Aches/Pain Sneezing Itchy/Watery/Red Eyes Itching of Nose/Throat Active Ingredients Chlorpheniramine Maleate 2 mg (antihistamine) Doctors give trusted answers on uses, effects, side-effects, and cautions: Dr. Menchell on can i take claritin and dayquil: DayQuil contains PHENYLEPHRINE a DECONGESTION similar to SUDAPHED! Rapid heart beat and a number of other symptoms are possible! Hope this helps! Dr Z If you’ve ever turned down a happy hour invite because you’re on antibiotics, you probably know that alcohol and medication can be a bad, even dangerous combination. Target is a shopper’s paradise! The national retailer offers a vast and ever-changing inventory that includes brand-name groceries and personal care items, fashion, home furnishings, holiday décor and more. choose offers on the things you love. Knock 5-50% off the price of hundreds of items. Read about the differences among three common over-the-counter antihistamines, Claritin, Allegra, and Zyrtec, and which one may be right for you. Doctors give trusted answers on uses, effects, side-effects, and cautions: Dr. Chand on can i take singulair with benadryl: Antihistamine is safe even with 4x the average daily dose. The major side effects would be dry mouth and drowsiness ( the latter much less common if one uses the non-sedating type).