Cough Medications - When to Use Them and What to Use By Mark B. Levin M.D., Timothy J. Patrick-Miller, M.D., and Louis J. Tesoro, M.D. The Pediatric Group, P.A., Princeton

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Although more common in the winter, coughing knows no seasonal limits. Given the myriad causes of coughing, determining when to worry, when to seek a physician and what medication to give can be difficult for parents. Bombarded by pharmaceutical advertising meant to increase sales, a medically naīve consumer is more likely to purchase and administer medications to their children based on advertising rather than knowledge. This article hopefully will provide you with the knowledge to be able to make rational decisions without guilt from among these choices. This article specifically omits management of medical conditions associated with chronic cough (cystic fibrosis, emphysema, tuberculosis, congenital malformations, etc.). These conditions must be medically managed with specific input from a child's personal physician.

The time of year can give you a clue to the likely cause of the cough, and, hence, the most effective treatment. For example, during Spring and Fall, allergies probably cause the majority of chronic coughs, whether by post-nasal drip or bronchospasm. (We chose to not use the term "wheezing", since it means different things to different people.) Respiratory infections, most commonly viral in origin but occasionally secondary bacterial infections, cause the majority of winter coughs. Sinus infections, a bacterial complication that can follow either allergic or viral inflammation, can supervene any time of the year.

Differentiating which coughs need medical attention, which need cough medication, which need supportive care and which to ignore is often perplexing. If a cough is not interfering with daily activities (e.g., eating, being active) or sleep, it is unlikely to require medical attention or medication. Coughs that stop at the end of a season are likely caused by allergy to something in the air during that season. Likewise, if a cough occurs only in a particular environment, it is likely that something in that environment triggers the cough. If the cough begins within days of other cold symptoms, the cough is probably part of a cold and need not be treated unless it is functionally impairing. Cough medications, particularly the over-the-counter varieties, are not particularly effective in curing the cause of the cough despite the claims of manufacturers. Conversely, a cough requires medical attention if it appears after three to five days into an illness, causes chest discomfort, is associated with recurrent fever, difficulty breathing, a sensation of a tight chest, vomiting, abdominal pain, pallor, lethargy, rashes or production of discolored sputum, or shows no predilection for daytime versus nighttime. Exposure to another person ill with pneumonia or bronchitis is not typically a risk factor for acquired pulmonary disease.

There are five broad categories of chemicals used in cough medications: cough suppressants, expectorants, decongestants, antihistamines and bronchodilators. Dextromethorphan is a cough suppressant. It is a non-narcotic derivative of codeine. Its pharmacologic property is simply to suppress the urge to cough by dulling the sensitivity of the nerves that control the cough reflex. Dextromethorphan is identified in cough medicine names by the use of the initials DM, D, DexM or DMX. Tesselon Perles (Benzonatate), an older medication in a gelule form, also works to deaden the cough reflex. These medications will not adequately control a cough whose underlying trigger is a post-nasal drip or a pulmonary infection. Side effects of Dextromethorphan include dizziness and fatigue. Some people experience sleeplessness. An overdose can cause neuropsychiatric symptoms. This medication has been abused as a street drug. Dextromethorphan should not be taken concomitantly with monoamine oxidase inhibitors (MAOI), which are used in some people to treat high blood pressure. Side effects of Benzonatate include drowsiness, mild dizziness, nasal congestion, constipation, headache, feeling of burning in the eyes, chills, or nausea.

Studies have shown the best expectorant to be water. Difficulty inducing an ill child to drink adequate fluids can make dried mucus clearance from the airway problematic. The primary chemical used as an expectorant is guaifensin (formerly called glyceryl guaiacolate). This agent thins the mucus to allow the cough to be effective in clearing it out of the lower airway. If used for a cough that is caused by nasal mucus production, guaifenesin may actually cause the nose to run more, exacerbating the cough! Expectorants are primarily helpful in the presence of pulmonary infections (pneumonia or bronchitis) and bronchospasm when fluid intake is inadequate.

Decongestants, of which there are two remaining in general use on the market (pseudoephedrine and phenylephrine), are adrenalin derivatives. Their intended pharmacologic action is to constrict blood vessels in the nasal passages. This is thought to impede mucus production and reduce swelling in the lining of the airway due to the increased blood flow cause by the inflammatory response. These medications are effective in some people and ineffective in others. Note, though, that they will not effectively dry up a runny nose. Side effects include nervousness, restlessness, dizziness, difficulty sleeping, upset stomach, difficulty breathing, fast or irregular heartbeat, muscle weakness, palpitations, tremors and hallucinations. These side effects may be potentiated by caffeine or combined use with other adrenaline derivatives. Decongestants should not be taken concomitantly with monoamine oxidase inhibitors (MAOI), which are used in some people to treat high blood pressure. A third decongestant, phenylpropanolamine (PPA), was removed from most medications in 2004 due to the risk of cardiac side effects.

Antihistamines are often added to decongestant products. This class of medication is intended to inhibit the inflammation and mucus production as a result of endogenous histamine production. Typically, histamine is released in the body during allergic reactions. As the mucus dries, allergy sufferers find relief from their itchiness and cough. Non-allergy patients sometimes find the dried nasal membranes and dry mouth associated with antihistamines use undesirable. Paradoxically, antihistamines do not relieve a runny nose caused by viral infections. Although antihistamines are often prescribed for allergy patients who also manifest bronchospasm, this same process in non-allergy patients may be exacerbated by antihistamines.

When bronchospasm is present, constriction of the bronchial muscles inhibits exhaling airflow. Coughing becomes inefficient in removing mucus at a time when mucus production is increased. Bronchodilators are used to relax the musculature around the lower airway, allowing mucus clearance. Bronchodilators (e.g., albuterol and salmeterol) are adrenaline derivatives. Side effects include fast heartbeat, nervousness, tremors, headache, difficulty sleeping or nausea. These side effects may be potentiated by caffeine or combined use with other adrenaline derivatives.

Three other factors are worth mentioning. A patient exposed to smoke (active or passive; tobacco, fire or other substances) can expect to cough without much beneficial effect from medication unless the offending agent is removed. Needless to say with all the information currently available about tobacco smoke, children (or anyone else) should NEVER smoke or be exposed to second hand smoke. Pregnant women should always check with their physician prior to taking any medication. Medication of any sort always carries the potential to interact with other medications and foods. Always check with your doctor or pharmacist regarding these possible interactions.

Here's hoping you recover quickly from your cough!

Dr. Mark B. Levin 

Dr. Levin has been a member of the staff at The Pediatric Group since 1977. Currently an attending Pediatrician at the Medical Center at Princeton, he has been Chairman, Department of Pediatrics, Medical Center at Princeton, 1984 to 1986, 1989 to 1992, and past President, Medical and Dental Staff, Medical Center at Princeton, 1987 to 1988. Dr. Levin has served on numerous Departmental and hospital committees. He has published original articles both while at Upstate Medical Center in Syracuse and at The Pediatric Group. He has a wife and three children. Dr. Levin enjoys alpine skiing, jogging, hiking and camping, travel, computers and racquetball.

Dr. Timothy Patrick-Miller Dr. Patrick-Miller has been a member of the staff at The Pediatric Group since 1985. Dr. Patrick-Miller has served on several Departmental and hospital committees. He has published original work while at The Pediatric Group. He and his wife enjoy travel. He also likes hiking, biking, gardening and reading.

Dr. Louis J. Tesoro

Dr. Tesoro has been a member of the staff at The Pediatric Group since 1988. Dr. Tesoro is Attending Pediatrician, Medical Center at Princeton, 1988 to present. He has served on several Departmental and hospital committees and was Chairman, Department of Pediatrics, Medical Center at Princeton from 1996 - 2000. He has lectured at the Universiy of Pennsylvania and has published original articles both while at The Children's Hospital of Philadelphia and at The Pediatric Group.

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