Q: I'm finding that so many over-the-counter medications warn against taking them if you have high blood pressure. Can you tell me why and what medications I should avoid?
A: It's funny, isn't it? We often assume that just because a medication is available without a prescription that it must somehow be safer than prescription medications. But the reality is that all drugs can have harmful side effects. Even aspirin can increase the risk of stomach bleeding, and acetaminophen (Tylenol) can contribute to liver damage.
Thus, the decision to use a specific medication should always depend on a complete understanding of its potential risks and benefits.
You are correct. Several over-the-counter (OTC) medications can contribute to high blood pressure. Others could interact with your high blood pressure medication, making it less effective. The OTC medications to watch out for include:
Pain relievers. Non-aspirin, nonsteroidal anti-inflammatories (NSAIDs) such as ibuprofen (Motrin) and naproxen (Alleve) can increase blood pressure even if you're already taking an anti-hypertensive medication. They appear to constrict blood vessels and increase the amount of sodium your body holds onto, both of which can cause high blood pressure. Chronic use of high-dose NSAIDs also causes kidney damage, which raises blood pressure.
Oral contraceptives. Birth control pills that contain estrogen can cause high blood pressure in about 5 percent of women who take them. That's why women with a history of high blood pressure or other risk factors for high blood pressure such as smoking are usually warned not to take estrogen-based contraceptives. Progestin-only pills are a contraceptive option for women with high blood pressure.
Antihistamines and decongestants. Products containing either of these ingredients (think Benadryl and Sudafed) can increase blood pressure and interact with your blood pressure medications. Check labels of allergy, flu and cold preparations, most of which contain one or both.
Weight-loss preparation. Many of these products contain antihistamines and other substances like caffeine that can increase blood pressure.