The cold season has arrived, a cure hasn’t, and even efforts at treating the symptoms seem doubtful.
Over the counter (OTC) cold remedies have come under harsh scrutiny lately. In October, an FDA advisory panel recommended a ban on cold medicines for children under six, and in anticipation of that vote, several drug makers pulled their infant cold medicines off the shelves. Medicines for adults weren’t affected, but they don’t have a track record that inspires great confidence. A drug called phenypropanolamine was used as a nasal decongestant in many products until researchers linked it to hemorrhagic strokes in women. Guidelines from the American College of Chest Physicians two years ago cast doubt on the effectiveness of cough expectorants and suppressants included in many over-the-counter products.
Little wonder, then, that people have sought out alternatives like vitamin C and zinc. But for the most part, the evidence for them is pretty shaky.
Over-the-counter medicines. Colds, of course, have a variety of symptoms, so cold medicines have a variety of ingredients: almost always some kind of pain and fever reducer, usually acetaminophen; a cough suppressant, often dextromethorphan; a nasal decongestant, usually phenylephrine; and sometimes an antihistamine, often chlorpheniramine. The American chest physicians aren’t alone in their skepticism about the anti-cough ingredients. Several years ago, British researchers reviewed 15 trials of cough medicines and concluded that “there’s no good evidence of their effectiveness.” Their damning assessment included antihistamines. The first generation antihistamine like doxylamine and chlorpheniramine have a sedating effect, so they’re often ingredients in the medicines that brag about nighttime relief.
If taken at the recommended dose, the OTC medicines are reasonably safe for adults. Still that’s a sizable if. Most of the complications from the infant and children’s formulations have come from accidental overdoses, which can be a problem for adults, too. People don’t necessarily read the fine print and may not realize, for example, that a tablespoon of Nyquil contains 500mg of acetaminophen. If they are taking lots of Tylenol - which is acetaminophen - at the same time, they can get into trouble that, in the worst case, may end in liver failure.
The possibility of anticholinergic effects from antihistamines is also something to keep an eye on. Particularly in older people, anticholinergic drugs can cause confusion, constipation and for men with prostate problems difficulty or inability to empty the bladder.
Pseudophedrine, the active ingredient in stand-alone nasal decongestant products like Sudafed, is a powerful medicine that needs to be taken with care. It works by constricting nasal blood vessels, but that effect isn’t limited to the nose. Pseudophedrine can cause hypertension and rarely, cardiac arrhythmias and strokes, as well as urinary retention in men with an enlarged prostate gland. It’s unclear whether phenylephrine, the nasal decongestant that has replaced pseudophedrine in many of the multi-symptom cold medicines, poses the same risk.
Vitamin C. Last year, a review of 30 trails that included a total of over 11,000 people found that taking the vitamin to prevent colds had little, if any, effect. Exceptions might be people who engage in heavy-duty exercise like marathon running or who are exposed to extreme cold. Such experiences cause temporary dips in immune function that vitamin C may offset. Whether mega doses might treat a cold once it’s started will require more research.
Zinc. Taking zinc has been proposed to shorten colds and perhaps reduce their severity. Stanford researchers reported last year that three of four studies that they identified as being the most reliable didn’t find a therapeutic benefit from zinc lozenges or nasal spray. The fourth, which tested a nasal gel, did. There have been several reports, though, of zinc gels causing a loss of the sense of smell.
Echinacea. A number of randomized clinical trials, included two funded by the National Institutes of Health, haven’t found any benefit from taking echinacea.
Prevention that works. Only a small percentage of sneezes and coughs contain cold viruses, so you’re more likely to spread - or pick up - cold viruses by way of your hands. Regular hand washing really is one of the best cold prevention tactics around. Exercising very hard may temporarily lower your immunological guard, but regular, moderate exercise boosts the immune system, and some research suggests it could prevent colds. Hopes for vitamin D are running sky-high these days, with research suggesting that it may have anti-cancer effects. It may also help fend off colds by boosting the immune system. But don’t go overboard. The safe daily upper limit for vitamin D is 2,000 International Units.
And once you get a cold… cold medicines aren’t the only OTC game in town. You can take many of the ingredients contained in these medicines separately, which allows for a targeted rather than a shotgun approach to symptoms. Aspirin or acetaminophen can ease the pain of a sore throat. Nonsteroidal anti-inflammatory drugs like naproxen (Aleve, other brands) can help with a cough.
Taking a decongestant isn’t the only way to open up nasal passages. Inhaling steam from a teakettle or in a hot shower can help. Drinking plenty of water helps unplug nasal passages by keeping mucus moist and flowing. Using a nasal irrigation device called a neti pot can help sinus sufferers. And if you have a fever, fluids counteract the tendency to get dehydrated.
Finally, don’t overdo the nose blowing. Too much blowing can push nasal fluids laden with bacteria and viruses into the sinus cavities. The result in some cases is a secondary infection of the sinuses that needs to be treated with antibiotics.
Taken in part from Harvard Health Letter, January 2008
Tags: antihistamines, cold medicines, cold season, cough expectorants, cough suppressant, hemorrhagic strokes in women, naxal decongestant, over the county cold remedies
