Over-the-counter cough and cold medicines have recently come under fire as risky - even potentially fatal - for children under the age of 2. Now, a review of existing research suggests there is little evidence that these medications even work for either children or adults.
"It's an important issue in relation to family medicine," says review co-author Thomas Fahey, a professor of general practice at the Royal College of Surgeons in Ireland medical school. "Lots of people come to their doctor, either with a cough themselves or more often with their child. And they often resort to taking over-the-counter remedies."
With a dearth of large-scale, definitive studies on the subject, Dr. Fahey and his team examined the most current research available. They looked at 17 studies involving a total of 2,876 adults and eight studies involving 616 children conducted in the United States, Britain, Europe, India, South Africa and Thailand. The studies compared various remedies, such as cough syrups, antihistamines and decongestants, with placebos.
Some studies showed the products worked, others showed they did not. So Dr. Fahey and his team concluded the evidence that the drugs work is weak, at best.
There are a couple of possible explanations, says London, Ont., pediatrician Michael Rieder, a member of the Canadian Paediatric Society's drug therapy and hazardous substances committee.
"One is they don't work at all and the other is that they work in some people," he says. "It's reasonable to presume there are some people who get benefit from it but there are a lot of people who don't."
What's more, the scant evidence in favour of over-the-counter remedies comes primarily from drug-industry-financed research.
Six of the nine studies supported by the pharmaceutical industry showed positive results of cold medications. Only three of the 16 trials without such a conflict of interest had positive results. "It's not a surprise, but it's not something we set out to look for," Dr. Fahey says, adding that other studies have shown industry-sponsored studies tend to have a more positive spin on the results.
The analysis is published in the current issue of the Cochrane Library, a publication of the Cochrane Collaboration, an international organization that evaluates medical research.
The only ingredients that showed slight promise for both adults and children were mucolytics, which are designed to break up phlegm. But because none of the studies were large, Dr. Fahey says, the evidence is not strong.
"Firm conclusions are going to be difficult. There's always a play of chance and when you have a small number of recruited patients, that chance effect is larger."
He says he will continue to seek public funding for a study of his own involving more than 1,000 patients.
In the meantime, Dr. Fahey says he will remain neutral on the use of all over-the-counter medications by adults.
"There's no evidence of benefit or harm, but they cost you money."
But for children, Dr. Fahey says he's especially concerned about ingredients such as antihistamines in light of evidence of health risks released by bodies such as the U.S. Food and Drug Administration. Last week, the FDA issued a new recommendation that these drugs should not be used in children under 2. It is now examining the safety of the drugs for children aged 2 to 11. Many of the companies that make the medications voluntarily recalled products aimed specifically at the under-2 set.
Gerry Harrington, spokesman for the Nonprescription Drug Manufacturers Association of Canada, disputes the conclusions of the review, especially those involving the cough suppressant dextromethorphan for adults, which was among the more positive findings.
Health Canada currently recommends that parents consult a health-care provider before giving these products to children under 2. The Canadian Paediatric Society recommends avoiding them until a child is 3, unless recommended by a doctor.
But many doctors, including Dr. Fahey, have hardened their stance on the products.
"I've changed my practice. I definitely don't recommend over-the-counter remedies in children any more," he says.
Dr. Fahey says it's important for doctors to remind adult patients and parents of ill children about the natural duration of a cough. "Most people don't appreciate that a cough usually lasts for two to three weeks and in itself is a protective mechanism."
In some cases, a cold can develop into a lower-respiratory infection or pneumonia, so he tells parents to watch for warning signs such as an uncontrolled temperature, lethargy and a lingering disinterest in food and drink.
Otherwise, most pediatricians and doctors recommend using a single pain-killing or fever-lowering drug such as ibuprofen if needed.Steaming can also be effective for both adults and children. "It may break up the phlegm."
Still, Dr. Fahey says, there's no hard evidence that such traditional remedies as steaming, drinking more fluids or using honey for a sore throat actually change the outcome of a cold, although they can't hurt.
And Dr. Rieder says that instead of running to the drug store, adults could learn from children's behaviour when they have a cold - they slow down and sleep.
"If you're not feeling well, don't think that you can just take some pills and rush off to work. Just stay home. Get better."