Despite safety warnings not to give sick toddlers cough and cold medications, almost half of parents in a recent survey are using the over-the-counter products anyway.

A poll released last month by researchers at the University of Michigan found that 42% of parents with children under the age of 4 gave them cough medicine, and 44% said they used multi-symptom cough and cold medications. A quarter of the parents said they used decongestants. The survey, which echoed some earlier studies' findings, arrives five years after the drugs' packages started including directions warning against their use in very young children.

Matthew Davis, a University of Michigan pediatrician who directed the survey, said he was surprised and concerned by the findings, which may show that parents aren't aware of the labeling and the history of worries about the drugs' use in young children. 'If you're a parent who doesn't know the story, you're going to think this [medicine] is for your kids,' he says.

The medications came under close scrutiny in 2008, when the Food and Drug Administration advised that they shouldn't be given to children under 2. That came after an agency advisory committee the previous year said children younger than 6 shouldn't take the medications. The panel concluded there wasn't evidence that the drugs helped young children, while FDA safety officials had suggested some of the drugs were associated with side effects and some deaths, mostly in very young patients and often involving overdoses.

Manufacturers agreed to put warnings on the products' boxes that they shouldn't be given to children under 4 years old. These appear today on medications that include dextromethorphan, a cough suppressant, the expectorant guaifenesin and the decongestants phenylephrine and pseudoephedrine. Medications with antihistamines warn against use in kids younger than 6. The children's cough and cold products are sold under brand names including Novartis AG's Triaminic and Pfizer Inc.'s Dimetapp and Robitussin.

The Consumer Healthcare Products Association, which represents makers of the over-the-counter medications, says research it sponsors shows the rate of safety issues with the drugs has been dropping. Most cases involve children taking them without parental supervision, it says. The 'drug facts' summary panel, often found on the back of a medication box, which includes dosing and other information, is the best place for the age warnings, rather than breaking them out on the front of the package, said David Spangler, a senior vice president with the association.

The association has sponsored a campaign to alert parents on how best to use the medications, including public-service announcements, social-media efforts and brochures for family physicians to distribute to parents. Representatives of the industry group also said it can be challenging to design, and enroll participants for, studies testing medicines for children's colds.

Pfizer said it 'encourages all parents to read and follow the label of any children's medication to determine appropriate use and dose.' A spokeswoman for Novartis said it declined to comment.

An FDA spokeswoman said the agency 'supports efforts. . .to better inform consumers about the safe and effective use of these products' and has worked with the Centers for Disease Control and Prevention on the issue.

Still, a study published in 2010 in the journal Child: Care, Health and Development, found that about a third of parents hadn't heard of the FDA recommendations, and of those who had, a third intended to keep using the medications. An earlier University of Michigan poll from 2011 found 61% of parents with children 2 and younger had given them cough and cold medications.

Another study, published recently in Clinical Pediatrics showed even higher numbers: 82% of 65 parents of children younger than 6 said they would use the medications, and nearly three-quarters of those indicated they would administer the wrong dose.

Some parents in that study would read the instruction not to give the medications to children younger than 4 and simply make up their own dose. They often extrapolated from doses recommended for older children, said Sarah G. Lazarus, a pediatrician at Children's Healthcare of Atlanta who was the lead author. She suggests the medications' age warnings, often found only in small print, may not be prominent enough on the packaging.

Doctors say they sometimes struggle to convince parents.

'They're using them because their children are sick, and they want to do something,' says Daniel Frattarelli, who chairs the American Academy of Pediatrics' committee on drugs. He advises against the drugs. But if a mom hears from a friend who has used them and believes they work, he said he expects sometimes to be ignored.

Parents who avoid the over-the-counter medications are instead branching out with other treatments. Margaret Willis of Dearborn, Mich., whose 16-month-old daughter is a patient of Dr. Frattarelli's, says she is 'frustrated' that there aren't any medicines for her toddler's frequent colds and coughs.

'There's nothing out there for a baby,' she says. After trying a number of alternatives, Ms. Willis, a preschool teacher, finally settled on a treatmentavailable on drugstore shelves that includes honey but no drugs, as well as a saline wash for the girl's nose. She believes the treatments helped somewhat, she says.

Doctors say they tell parents to try elevating their children's heads at night -- with babies, who aren't supposed to have objects in their cribs, parents can put towels under one end of the mattress or even use the car seat. Steam from a hot shower can also help, though some doctors warn that parents need to be careful with humidifiers, since they can develop mold.

Suctioning the nose is another option, as well as acetaminophen for fever, and another old standby: 'Lots of fluids,' says Alanna Levine, a pediatrician in Tappan, N.Y. For children older than 1 suffering from a cough, she also recommends a spoonful of honey, she says. Honey isn't recommended for babies because of the possibility it carries spores that could lead to botulism. One key goal in trying to soothe coughs is to help toddlers get adequate sleep, doctors said.

Jennifer Chang, the mother of a 9-month-old and a 3-year-old who see Dr. Levine, has tried a honey-based preparation, as well as steamy showers and hydration.

'It seems like there's not a whole lot you can do,' says Ms. Chang, of Nyack, N.Y. 'I want to make it feel better.' Subscribe to WSJ: http://online.wsj.com?mod=djnwires