Older (first-generation) over-the-counter and prescription antihistamines
Newer (second-generation) over-the-counter antihistamines
Newer (second-generation) prescription antihistamines
Antihistamines may be available as tablets, capsules, nasal
sprays, or liquids.
How It Works
Many symptoms of allergic rhinitis, such
as sneezing, itching, and runny nose, occur when your body releases a chemical
Antihistamine medicines block histamine and may reduce
Why It Is Used
You can use antihistamines to stop
or reduce sneezing, runny nose, and watery and itchy eyes caused by an
How Well It Works
All of these antihistamines work
equally well to relieve sneezing, itching, and runny nose.
- Antihistamines begin to provide relief in 30 minutes to 2
- Antihistamines dry up the runny nose caused by allergies, but
they usually do not clear up stuffiness.
All medicines have side effects. But many people don't feel the side effects, or they are able to deal with them. Ask your pharmacist about the side effects of each medicine you take. Side effects are also listed in the information that comes with your medicine.
Here are some important things to think about:
- Usually the benefits of the medicine are more important than any minor side effects.
- Side effects may go away after you take the medicine for a while.
- If side effects still bother you and you wonder if you should keep taking the medicine, call your doctor. He or she may be able to lower your dose or change your medicine. Do not suddenly quit taking your medicine unless your doctor tells you to.
Call911or other emergency services right away if you have:
- Trouble breathing.
- Swelling of your face, lips, tongue, or throat.
Call your doctor if you have:
- Fast or irregular heartbeat.
- Unusual bleeding or bruising.
- Belly pain.
- Unusual tiredness or weakness.
Common side effects of this medicine include:
- Dry mouth, nose, or throat.
- Stomach upset.
See Drug Reference for a full list of side effects. (Drug
Reference is not available in all systems.)
What To Think About
In general, antihistamines don't
relieve nasal congestion well. They are often combined with a decongestant in
one product. These medicines may not be safe for young children or for people who have certain health problems. Read and follow all instructions on the label.
Medicine is one of the many tools your doctor has to treat a health problem. Taking medicine as your doctor suggests will improve your health and may prevent future problems. If you don't take your medicines properly, you may be putting your health (and perhaps your life) at risk.
There are many reasons why people have trouble taking their medicine. But in most cases, there is something you can do. For suggestions on how to work around common problems, see the topic Taking Medicines as Prescribed.
Advice for women
If you are pregnant, breast-feeding, or planning to get pregnant, do not use any medicines unless your doctor tells you to. Some medicines can harm your baby. This includes prescription and over-the-counter medicines, vitamins, herbs, and supplements. And make sure that all your doctors know that you are pregnant, breast-feeding, or planning to get pregnant.
Follow-up care is a key part of your treatment and safety. Be sure to make and go to all appointments, and call your doctor if you are having problems. It's also a good idea to know your test results and keep a list of the medicines you take.
Complete the new medication information form (PDF)(What is a PDF document?) to help you understand this medication.
Primary Medical Reviewer
||E. Gregory Thompson, MD - Internal Medicine
Specialist Medical Reviewer
||Rohit K Katial, MD - Allergy and Immunology
Current as of
||March 12, 2014