Side Effects of Taking an Antihistamine
As with any medication, over the counter or prescribed by a doctor, side effects are possible. Not everyone will always see the same side effects from the same medication, and some never experience any side effects at all. Even with over the counter medications, your doctor should have a list of every medication you take to be sure that you will not have any adverse reactions due to a medication that is already present in your system.
Some common side effects of antihistamine drugs are as follows: drowsiness, headache, dizziness, upset stomach, dry mouth, loss of appetite, vision changes or double vision, irritability, confusion, constipation and difficulty urinating. Drinking alcohol while taking an antihistamine can cause the side effects experienced to become worse. If experienced, these side effects should only last for the duration of time you are taking this medication. If the side effects are prolonged, or become bothersome to you, you should contact a doctor right away. While everyone may experience at least one of these side effects, they are more likely to occur in small children and the elderly.
The use of antihistamines (OTC or prescribed by a doctor) is generally safe. However, people who have glaucoma, asthma, chronic bronchitis, and emphysema, trouble urinating due to an enlarged prostate, heart disease, thyroid problems, high blood pressure, or a person currently taking other medication should not use an antihistamine without first consulting with a doctor and going over all of their personal potential side effects and options for other medications.