Cough/cold combinations are used mainly to relieve the cough due to colds, influenza, or hay fever. They are not to be used for the chronic cough that occurs with smoking, asthma, or emphysema or when there is an unusually large amount of mucus or phlegm (pronounced flem) with the cough.
Cough/cold combination products contain more than one ingredient. For example, some products may contain an antihistamine, a decongestant, and an analgesic, in addition to a medicine for coughing. If you are treating yourself, it is important to select a product that is best for your symptoms. Also, in general, it is best to buy a product that includes only those medicines you really need. If you have questions about which product to buy, check with your pharmacist.
Since different products contain ingredients that will have different precautions and side effects, it is important that you know the ingredients of the medicine you are taking. The different kinds of ingredients that may be found in cough/cold combinations include:
Antihistamines—Antihistamines are used to relieve or prevent the symptoms of hay fever and other types of allergy. They also help relieve some symptoms of the common cold, such as sneezing and runny nose. They work by preventing the effects of a substance called histamine, which is produced by the body. Some examples of antihistamines contained in these combinations are:
Decongestants—Decongestants produce a narrowing of blood vessels. This leads to clearing of nasal congestion. However, this effect may also increase blood pressure in patients who have high blood pressure. These include:
Antitussives—Antitussives help relieve coughing and are some contain a narcotic. These antitussives act directly on the cough center in the brain. Narcotics may become habit-forming, causing mental or physical dependence, if used for a long time. Physical dependence may lead to withdrawal side effects when you stop taking the medicine.
Expectorants—Expectorants work by loosening the mucus or phlegm in the lungs. The main expectorant used in cough and cold medicines is guaifenesin. Other ingredients added as expectorants (for example, ammonium chloride, calcium iodide, iodinated glycerol, ipecac, potassium guaiacolsulfonate, potassium iodide, and sodium citrate) have not been proven to be effective. In general, the best thing you can do to loosen mucus or phlegm is to drink plenty of water.
The use of too much acetaminophen and salicylates at the same time may cause kidney damage or cancer of the kidney or urinary bladder. This may occur if large amounts of both medicines are taken together for a long time. However, taking the recommended amounts of combination medicines that contain both acetaminophen and a salicylate for short periods of time has not been shown to cause these unwanted effects.
Anticholinergics—Anticholinergics, such as homatropine may help produce a drying effect in the nose and chest.
Do not give any over-the-counter (OTC) cough and cold medicine to a baby or child under 4 years of age. Using these medicines in very young children might cause serious or possibly life-threatening side effects .