In a study prompted by the 2005 deaths of three children under the age of 2 years old, the Centers for Disease Control and Prevention (CDC) advised parents Thursday not to give over-the-counter cold remedies to a child under 2 years old without first consulting the child’s pediatrician.

The children who died were all between the ages of 6 months or younger; and all of them had high levels of the drug pseudoephedrine in their systems, as much as 14 times the dose recommended for children between the ages of 2 to 12.

Pseudoephedrine, which is commonly used in over-the-counter nasal decongestants, is part of a class of drugs known as sympathomimetic agents. Sympathomimetics mimic a stimulated sympathetic nervous system. When your sympathetic nervous system is triggered because your body senses danger, it causes your blood pressure to increase, your heart to beat faster, and your digestion to slow down. When you take a drug that is classified as a sympathomimetic agent, it produces these same effects in your body.

People generally assume that over-the-counter drugs are safe to take because you don’t need a doctor’s prescription to buy them; and in most cases they are if they are used according to the directions printed on the bottle or box. These directions will tell you how much medicine to give, how often to give it, what is in the medication, warnings about using it such as possible side effects, and if the medication is safe for children.

If the box or bottle does not contain a recommended dosage for children under 2 years old, always ask your child’s doctor if it is okay for your child to take it before you give it to him/her. Also be sure to ask the pediatrician how much your child should take and how often.

If the pediatrician does permit your child to take the medication, keep a medicine log and record the amount of the dosage and the time you administered it each time your child takes the medicine. Keeping this type of log will prevent you from overdosing your child because you can check the written record if you forget whether or not you have already given the child the medication.

There are some other steps you can take to reduce your child’s discomfort besides administering medication.

-- Nasal congestion is a very common and annoying symptom your child experiences when s/he gets a cold. Use a humidifier in the child’s room to keep nasal passages from drying out. If the passages remain moist, the mucus will be easier for your child to blow out.

-- You can also use a saline solution to relieve nasal congestion. Put the solution in your child's nose and then suction the liquid and the mucus out with a nasal bulb syringe. You can buy a nasal syringe in your local drugstore.

-- Use an over-the-counter saline solution, or create your own by dissolving a 1/4 teaspoon of pure, non-iodized salt in 8 ounces of distilled or filtered warm water. Be sure to discard any solution after 24 hours and create a fresh solution for your child every day.

As the weather gets colder, your children will become more susceptible to colds. Be careful before you give them any medication. Never assume because the medicine is all right for you, it’s all right for them. Always check with your pediatrician before administering any over-the-counter remedy especially if the child is younger than 2 years old.

Foxnews.com Health contributor Maria Esposito contributed to this report.

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Dr. Manny Alvarez is the managing editor of health news at FOXNews.com, and is a regular medical contributor on the FOX News Channel. He is chairman of the Department of Obstetrics and Gynecology and Reproductive Science at Hackensack University Medical Center in New Jersey. Additionally, Alvarez is Adjunct Professor of Obstetrics and Gynecology at New York University School of Medicine in New York City.

Dr. Manny Alvarez serves as Fox News Channel's senior managing health editor. He also serves as chairman of the department of obstetrics/gynecology and reproductive science at Hackensack University Medical Center in New Jersey. Click here for more information on Dr. Manny's work with Hackensack University Medical Center. Visit AskDrManny.com for more.