High Blood Pressure and Antihistamines

There has been an ongoing talk about antihistamines causing blood pressure to rise. This is simply not true. Antihistamines alone cannot affect blood pressure. However, patients taking antihistamines are also taking decongestants. This combination of medications will clear congestion and help in fast recovery from allergic reactions and cold, but can also cause an increase in blood pressure for people with existing high blood pressure.

In addition, while antihistamines do not have a direct effect on a person's blood pressure, they can have interactions with other drugs that a patient with high blood pressure may be taking. Antihistamines are known to interact with muscle relaxers and sedatives. Before you take any combination of medications, always tell your doctor about it. Ask your physician if you can take antihistamines while you are undergoing medication treatment for high blood pressure. Your doctor may find a way to prescribe blood pressure medication and antihistamines in dosages that can minimize side effects and complications. Normally, each drug should be taken hours apart. 

Just to be on the safe side, avoid taking any combined medication unless approved by a professional.