Be sure to read medicine labels

If you have multiple cold or flu symptoms, be sure to read the label to avoid dangerous drug interactions or overdoses.

Know the ingredients and ask your doctor or pharmacist before combining any medications -- prescription, over-the-counter, herbal remedies or vitamins -- said the emergency doctors at emedicinehealth.com.

One common ingredient to watch for is acetaminophen, the active ingredient in Tylenol and many other over-the-counter and prescription drugs.

An acetaminophen overdose can cause serious liver damage and in some cases require an organ transplant.

Never mix different medications if both medications contain acetaminophen unless instructed to do so by your doctor, according to emedicinehealth.com.

For example, a flu sufferer might seek relief from fever, body aches, cough and congestion. He or she should not take both acetaminophen with codeine and a cold medicine containing acetaminophen at the same time.

Here are some common over-the-counter drugs designed to relieve multiple symptoms, listed with their active ingredients.

n Vicks NyQuil Multi-Symptom Cold/Flu Relief:

Acetaminophen (pain reliever/fever reducer)

Dextromethorphan HBr (cough suppressant)

Doxylamine succinate (antihistamine)

n Tylenol Cold Multi-Symptom:

Acetaminophen (pain reliever/fever reducer)

Phenylephrine HCl (nasal decongestant)

Dextromethorphan HBr (cough suppressant)

Doxylamine succinate (antihistamine)

n Triaminic Night Time Cough and Cold:

Phenylephrine HCl (nasal decongestant)

Diphenhydramine HCl (antihistamine/cough suppressant)

n Theraflu Nighttime Severe Hot Liquid:

Acetaminophen (pain reliever/fever reducer)

Pheniramine maleate (antihistamine)

Phenylephrine HCl (nasal decongestant)

-- Katie Foutz, staff writer