There are different types of antihistamines, and some are better than others depending on your age, health and other medications you take.
Older formulas work, but beware of side effects and bad interactions
Doctors often refer to the first type of antihistamines that were on the market as “first-generation.” They are great at treating allergy symptoms. Unfortunately, in some people, they can result in side effects like anxiety, confusion, feeling sleepy, blurred vision, reduced mental alertness, urinary retention and constipation. These effects are more common for anyone taking certain antidepressant medications.1
Ingredients to look for include brompheniramine, chlorpheniramine, dimenhydrinate, diphenhydramine and doxylamine.2 Ask a pharmacist to help you compare products and read the labels if the print is too small. Some of the brand names for these products include Actifed Cold, Benadryl, Vicks NyQuil and Tylenol Cold and Cough Nighttime.2
The labels should also include warnings that people with certain medical conditions should not take first-generation antihistamines.2 Ask your doctor before use if you have:
- trouble urinating (from an enlarged prostate gland)
- breathing problems, such as asthma, emphysema, or chronic bronchitis
- thyroid disease
- heart disease
- high blood pressure
New formulations have fewer side effects, but you still need to be cautious
So-called “second-generation” antihistamines have fewer side effects and can be taken fewer times during the day. Again, ask your pharmacist to help you compare products. Ingredients in these products include loratadine, cetirizine and fexofenadine.2 In the pharmacy, the brand names include Claritin, Zyrtec and Allegra.2
There is still a potential for negative effects with certain illnesses. Talk to your doctor before taking a second-generation antihistamine if you have kidney or liver disease.2
Medicines that treat multiple cold, flu and allergy symptoms include these second-generation antihistamines. When possible, only take medicines that treat your current symptoms.
Ask your doctor and the pharmacist
You should always consult your doctor before taking a new medication. Ask about potential side effects and interactions with drugs you already take. See if there are alternatives that would be better for you, and only take the medication as directed.
If you have additional questions at the pharmacy, the pharmacist can help you read labels, compare products and make recommendations.
1 American Academy of Allergy Asthma & Immunology: Medications and older adults. https://www.aaaai.org/conditions-and-treatments/library/allergy-library/medications-and-older-adults. Accessed on April 9, 2019.
2 FamilyDoctor.org. Antihistamines: Understanding Your OTC Options. https://familydoctor.org/antihistamines-understanding-your-otc-options/. Accessed on April 9, 2019.
About Wayne Rawlins, MD, MBA
Dr. Wayne Rawlins, vice president and chief medical officer at ConnectiCare, is a former member of the National Vaccine Advisory Committee, where he worked with the U.S. Department of Health and Human Services to advise and make recommendations on national vaccine policy.