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Hidden Hazards of Cold Medicines

You may get the relief you want, plus a few side effects you don't

Hidden Hazard Cold Medicine Sick Bottle Spoon

Stuart Bradford

Decongestants may cause your blood pressure to spike.

En español l Over-the-counter cold medications can help relieve that stuffy nose and scratchy throat, but sometimes they do more harm than good. "People think that because they can buy these remedies without a prescription, they're safe," says Leigh Ann Mike, a pharmacist on faculty at the University of Washington School of Pharmacy. "But that's not always true." Here are some of the hazards to look out for — and some ways to avoid them.

Acetaminophen and liver damage

If you use acetaminophen (such as Tylenol) to ease arthritis pain, pop an acetaminophen tablet to quell a headache and add a combination cold medication for sniffles, you've gone well over the maximum safe daily dose of 3,000 to 4,000 milligrams of this common pain reliever. Each year, about 78,000 people land in the emergency room for acetaminophen toxicity, which can lead to severe liver damage.

Initial symptoms — including nausea, vomiting, stomach pain and loss of appetite — are often vague and may mimic those of a cold. Later symptoms include dark urine and a pain on the upper right side of the body. If you suspect an acetaminophen overdose, seek immediate help.

Stay safe: Stay away from alcohol if you're taking acetaminophen. Take the lowest dose that brings relief, stick to the recommended timing and read labels carefully. Many medications contain acetaminophen, so you may be taking more than you realize.

Ibuprofen and ulcers, kidney problems

Ibuprofen (in Advil and Motrin) is a nonsteroidal anti-inflammatory drug (NSAID) that effectively relieves body aches, headaches and fever. It may cause a severe allergic reaction as well, especially in people allergic to aspirin, and can cause peptic ulcers and kidney damage with chronic use.

Ibuprofen may also increase the risk for a heart attack or stroke, especially if you already have heart disease or high blood pressure, you smoke, you have diabetes or you use it long-term.

Stay safe: Avoid alcoholic beverages if you take ibuprofen regularly. Call your doctor immediately if you develop bloody or black, tarry stools; if you experience changes in the frequency of urination; or if you have problems walking or with your vision or speech.

Decongestants and high blood pressure

Decongestants, such as Triaminic and Dimetapp Cold Drops, relieve nasal congestion by reducing swelling and constricting blood vessels in the nose, allowing you to breathe more easily. Unfortunately, decongestants have a dark side. They can cause blood pressure to spike and interfere with the effectiveness of prescription medications to control blood pressure.

Decongestant nasal sprays like Afrin Nasal Spray and Neo-Synephrine clear up a stuffy nose almost immediately and cause fewer side effects than decongestants taken by mouth. "But if you use sprays or drops for more than the recommended three days in a row maximum, the tissues lining your nose and sinuses can become dependent on them and you'll start using more and more in an effort to breathe easily again," says Boston University pulmonologist and allergist Frédéric Little.

If you experience shortness of breath, irregular or slow heartbeat or unusual nervousness, seek medical help immediately.

Stay safe: If you have a heart condition, high blood pressure, diabetes, glaucoma or an overactive thyroid, talk with your doctor before using a decongestant.

Antihistamines and falls

Short-acting antihistamines, such as Benadryl and Chlor-Trimeton, block the production of the compound histamine and can relieve the symptoms of a runny, itchy nose. The effects of short-acting antihistamines last for approximately four hours, notes Little. They also tend to make people sleepy, a side effect that can be helpful before bedtime.

However, that sleepiness "can be a problem for older adults who get up in the middle of the night," he says. Antihistamines can impair coordination, slow reaction time and affect judgment, increasing the risk of falls.

Longer-acting antihistamines such as Claritin, Zyrtec and Allegra are generally taken once a day and don't usually cause sleepiness. Although they're commonly used for allergies, they can also help ease the scratchy throat and runny nose that accompany a cold.

Stay safe: Talk to your doctor before using a short-acting antihistamine if you have glaucoma, an enlarged prostate, breathing problems, high blood pressure or heart disease. If you take a longer-acting antihistamine and develop hives or a rash or have difficulty breathing or swallowing, call your doctor immediately.

Combination meds and heart problems

New Zealand researchers recently found that over-the-counter cold remedies that combine acetaminophen with the decongestant phenylephrine (Contac Cold+Flu Non-Drowsy, Theraflu Daytime Severe Cold & Cough) can bring on serious side effects, including an irregular heartbeat, dangerously high blood pressure and tremors.

Stay safe: Consider treating only the symptoms that bother you by using a single-ingredient medication. If you opt for a combination, read the active ingredient list on the label to make sure that your other medications don't contain the same ingredients.

Nissa Simon is a freelance writer who lives in New Haven, Conn.

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