Dealing with your cough cough

Dealing with your cough cough
FACULTY OF HARVARD MEDICAL SCHOOL
01/03/07 00:00:00

Q: Every winter I get a least one bad cold, which is often followed by a lingering cough. The sheer number of different cough remedies always bewilders me. Which ones work best?

A: A persistent cough isn't only annoying, it can also keep you up at night, leaving you exhausted and run down. No wonder we make 30 million trips to the doctor each year and spend roughly $3.5 billion annually on over-the-counter (OTC) pills, capsules and syrups for cough and cold-related woes.

Experts say much of that money is wasted. According to guidelines from the American College of Chest Physicians, many of the 'active' ingredients in famous OTC cough remedies like Robitussin and Vicks Formula 44 are ineffective.

As your experience shows, most coughs are triggered by colds. When you get a cold, the virus takes up residence in the moist recesses of your nose and upper respiratory tract. The tissue lining those areas doesn't take kindly to the intrusion and responds by producing excess mucus. One result is postnasal drip, a trickle of mucus that stimulates nerves at the back of the throat to produce coughing, especially when you're lying down (see illustration).

Most of the common OTC cough medicines contain two main ingredients, expectorants and suppressants. Expectorants affect how much mucus you make, its consistency and how quickly your body gets rid of it. The most common one, guaifenesin (pronounced gwy-FEN-e-sin), thins mucus. Some studies show it's effective, but others disagree. Want a free, reliable way of loosening mucus? Just try drinking plenty of water.

Suppressants act on the central nervous system to tamp down the cough reflex -- or at least that's how they should work. Dextromethorphan (pronounced dex-tro-meth-OR-fan) is the most common. Both dextromethorphan and codeine (a mild narcotic used mainly in prescription formulations) seem to reduce some symptoms of bronchitis. Bronchitis is an infection in the tubes that connect the windpipe to the lungs, which causes persistent coughing. But suppressants don't work well for coughs caused by colds.

Instead, you'd be better off taking an older antihistamine (allergy medicine) and a decongestant, according to the experts. (Note that several other conditions can also cause postnasal drip and its resulting cough, including sinusitis, exposure to air pollution, hay fever and other nasal allergies).

Antihistamines can work in several ways. They block histamine, an amino acid that makes blood vessels leaky. This causes the runny nose and watery eyes that make allergies such a bother. But histamine isn't involved in symptoms of the common cold. However, older antihistamines like brompheniramine and chlorpheniramine have another effect. They affect a specific brain chemical in a way that reduces mucus production and widens airways. Newer nondrowsy antihistamines, like loratadine (Claritin), have less of this effect and aren't effective as cough suppressants. The only older antihistamine that is specifically recommended is brompheniramine. But you might try other older antihistamines, such as diphenhydramine or chlorpheniramine, to see whether they work for you.

Decongestants work by constricting blood vessels, which shrinks swollen membranes and allows more air to pass through nasal passages. As a result, tissues dry out, so there is less postnasal drip. Pseudoephedrine (pronounced sue-doe-e-FED-rin), the active ingredient in Sudafed, and phenylephrine (pronounced fen-ill-EF-rin) are the most common decongestants. However, decongestants can present problems. You can become dependent on decongestant nose drops if you use them for more than four consecutive days. And pseudoephedrine has many potential side effects ranging from wakefulness to increased blood pressure to an irregular heartbeat.

But these medication suggestions are just guidelines. The studies they're based on can't possibly reflect every individual experience. If you think a product is working fine, it probably won't hurt you. But you may be paying for a placebo effect.

Always keep in mind the other, common causes of a lingering cough, such as asthma and gastro-esophageal reflux. If you have a cough that you just can't shake, see your doctor to check out the possibility of other causes of your misery. OTC cough remedies rarely remedy anything, but a correct diagnosis can lead to treatment that quiets your cough.

From http://www.northpeel.com/br/lifestyle/story/3829545p-4430755c.html