Cough syrup
has been used for decades to relieve coughs due to the common cold, but
in most cases it seems to be a waste of money, medical experts told United
Press International.
The main ingredients
in cough syrup are suppressants to stifle a cough and expectorants to make
it easier to cough up phlegm.
With most coughs
due to colds and minor illness, cough syrup ingredients are a "total waste
of money," said Vincenza Snow, senior medical associate at the American
College of Physicians-American Society of Internal Medicine, a group representing
more than 100,000 doctors.
The Merck Manual
of Diagnosis and Therapy, a reference book used by physicians and written
by an editorial board of medical experts, offers similar advice. Suppressing
a cough generally is not recommended, and there is little evidence to show
the expectorants provide any benefit, the manual says. Guaifenesin, the
expectorant most commonly used in cough syrups, "has no serious adverse
effects, but there is no clear evidence of its efficacy," the manual says.
"There was never
any evidence that expectorants are of any benefit in upper or lower respiratory
tract infections," Snow said. Any benefit is likely from a placebo effect
or the false perception that symptoms have improved, she said. "People
start taking these medications ... at about the time when they really can't
stand it anymore, which is about the time they would start feeling better
anyway," she said. "So they associate improvements with whatever they took."
"I do not think
that there's great science there" to support the effectiveness of expectorants,
Brian Bates, a physician in the emergency department at Methodist Children's
Hospital in Borne, Texas, told UPI. Instead of using a cough syrup containing
an expectorant, "probably just as good if not better is increasing a child's
liquid intake," said Bates, who is a member of the American Academy of
Pediatrics' committee on drugs. "That's usually enough to bring up mucus
on its own," he said.
The Merck Manual
concurs, stating, "Adequate hydration is the single most important measure
that can be taken to encourage expectoration."
The Food and
Drug Administration maintains that expectorants do have a benefit. "If
a product performs better than placebo, then it's approvable as effective"
under FDA regulations, spokeswoman Laura Bradbard told UPI, adding cough
syrups would not be available to consumers if they were ineffective. As
long as the drug is better than placebo, "the amount of effectiveness is
not a concern to FDA," Bradbard said.
Wyeth Consumer
Healthcare in Madison, N.J., which manufactures the Robitussin line of
cough syrups, defended the effectiveness of their products.
Robitussin cough
syrups are primarily intended to be used to stifle cough as a convenience
to help people sleep or work, said Wyeth spokesman Fran Sullivan. "There
are studies out there that show that they do work and that there is some
benefit to them," he said.
In addition,
there's some real-world evidence to support their effectiveness, he said,
noting that Robitussin syrups are widely used by the public, with sales
in the tens of millions of dollars in the United States each year.
Snow conceded
that cough suppressants are effective but noted in most cases that it would
be unwise to suppress a cough. "Conventional wisdom is that if a patient
is producing phlegm with cough, then you should not suppress the cough
because it is a defense mechanism to get the phlegm out," she said.
The Merck Manual
gives similar advice. "A productive cough should not be suppressed except
in special circumstances (e.g., when it exhausts the patient or prevents
rest and sleep)," it says.
Bates agreed.
"It's important to know why people are coughing before you throw medicine
at it," he said. "In a lot of conditions a cough is beneficial, like pneumonia.
It's good to cough up the mucus rather than let it sit in the lungs where
it can cause problems."
In addition,
suppressants can have unwanted side effects, particularly in children.
"In doses recommended for suppression ... the side effects of some of these
medications outweigh the benefit, and the child can become very fussy and
then you don't know what's going on," Bates said.
However, suppressants
may be recommended if a child has "a mild cough that's interfering with
their sleep," he said, noting he will use the medication for his own children,
but only at night.
Another reason
for using a cough suppressant is if a person has a dry, hacking cough,
Snow said. But she noted that this condition might be due to a spasm in
lung muscles and the person may benefit more from asthma treatment.
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Copyright 2003 by United
Press International.
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