Cough is among the most common maladies for which pharmacists are consulted for treatment. Many people tend to trivialize cough as just another annoying symptom of an upper respiratory infection, but a nagging cough can slow recovery, and a severe cough can even be dangerous for some people. When choosing cough medicine, most people rely on what they?ve seen advertised or what may have seemed to work previously, but treating a cough properly is complex and requires careful application of both clinical and pharmacologic insight that may be unique to the pharmacist. Cough is usually accompanied by underlying problems that can range from benign and self-resolving to chronic or even life-threatening, depending on patient variables and comorbid illness. Effective treatment involves addressing or resolving the underlying cause while recognizing the significance of the cough itself on one?s overall health.
Take Cough Seriously
Far from a trivial annoyance, cough has developed over time as a protective mechanism to expel material that doesn?t belong in the respiratory tract. Cough can become a serious health problem, however, causing severe complications, especially in someone who is already ill or debilitated. Severe or uncontrolled cough can:
- Damage surgical incisions or wounds
- Impair the function of catheters and surgical shunts
- Cause soreness of the muscles used in coughing from overuse, making recovery from illness extremely painful
- Cause urinary or bowel incontinence, which can cause emotional trauma
- Damage bodily structures: fractured ribs; ruptured muscles of the abdomen; ruptured subconjunctival, nasal, and anal veins; ruptured spleen; inguinal or pulmonary herniation; inversion of the bladder through the urethra; pulmonary interstitial emphysema; and neck problems
- Cause neurologic problems such as dizziness, headache, hypotension, loss of consciousness, stroke, arrhythmia, venous hypertension, decreased cardiac output, increased vagal tone, and heart block
Treatment of cough should be aimed at mobilizing and expectorating bronchial secretions and minimizing abnormal stimulus of cough receptors by removal of irritation. The old tenet that only the nonproductive cough should be suppressed cannot be universally applied, because reducing the frequency of even a productive cough can facilitate rest and recovery in many cases.
Accepted methods for treating cough include:
- Demulcents: Water (increasing fluid intake or use of a vaporizer), hard candy, lemon, honey, menthol, camphor, or simple syrup coat the mucous membranes and cough receptors near the larynx to prevent irritation of airway receptors. They are not effective farther away from the larynx.
- Anesthetics: Lozenges, gargles, or sprays containing benzocaine, lidocaine, benzyl alcohol, or phenol numb cough receptors. Examples of products with anesthetics include Sucrets and Spec-T. They are not effective farther away from the larynx. Side effects include oral numbness, stomach upset, diarrhea, loss of appetite, and hypersensitivity.
- Expectorants: Products containing guaifenesin (eg, Safe Tussin) facilitate removal of secretions by enhancing the breakdown of mucus and increasing sputum volume.
- Antihistamines: These agents dry secretions to reduce sputum production and expand the bronchial air passages, but they can produce sedation. Examples of products containing antihistamines include Benadryl Allergy/Cold and Coricidin Cough & Cold. The newer nonsedating antihistamines lack the efficacy of the older agents in this application.
- Sympathomimetic decongestants: These products can reduce nasopharyngeal edema and postnasal drip, but they contain ingredients that can cause excessive central nervous system stimulation and insomnia, nervousness, and tremor. Examples of products containing decongestants include Tylenol Cold, Advil Cold & Sinus, and Sudafed Severe Cold Formula.
- Central suppressants: Products containing dex-tromethorphan suppress cough via the central nervous system. Side effects in nonprescription dosages are usually minimal; but constipation and sedation can occur in elderly persons. Examples include Safe Tussin, Robitussin DM, and Alka Seltzer Plus Flu.
The Potential for Side Effects
Many pharmacologic remedies for cough are capable of causing significant side effects, even in nonprescrip-tion doses. In patients with various illnesses and those taking other medications, either prescription or nonpre-scription, these products can be outright dangerous. According to the FDA, nonprescription doses are generally safe for most potential users, and manufacturers are diligent about adequate caution labeling; but patients must read warnings and follow directions.
What to Avoid
First-generation antihistamines should not be taken by patients with narrow-angle glaucoma, peptic ulcer, prostatic hypertrophy, bladder neck obstruction, or pyloroduodenal obstruction. Elderly and debilitated patients and those taking monoamine oxidase inhibitors should also avoid these agents.
- Sympathomimetic decongestants should generally be avoided by those with hyperthyroidism, diabetes mellitus, cardiovascular disease, coronary artery disease, ischemic heart disease, increased intraocular pressure, or an enlarged prostate.
- Most cough products contain large amounts of alcohol, which can be a problem for many individuals. Children and patients with hypertension, diabetes, or alcoholism should avoid products containing alcohol.
- Products containing acetaminophen, aspirin, or ibuprofen should be used judiciously by patients with hepatic compromise, and otherwise healthy patients taking them should be careful not to take additional acetaminophen, aspirin, or ibuprofen, which is a common mistake. People with asthma, nasal polyps, chronic itching, or gastric reflux or a related state and those on anticoagulant therapy should avoid these products.
- Sodium, an ingredient often found in both prescription and nonprescription medications, should be avoided by patients with cardiovascular disease or sodium-sensitive high blood pressure.
- Products containing sugar should be avoided by patients with diabetes, because they are more vulnerable to disruptions in glycemic control when ill.
- Elderly people can be particularly susceptible to problems with nonprescription cough remedies, because they often have other chronic illnesses and take medications for those illnesses, which increases the risk of drug interactions. In addition, the ability to metabolize medications diminishes with age, so dosages of even nonprescription agents may need to be adjusted.
- Pregnant women and nursing mothers should beware of medications, because the list of agents with the potential for affecting the fetus or nursing child is long and growing. This risk is not diminished by non-prescription status.
- Caution must always be used when giving medicine to children. They should avoid products containing alcohol or any unnecessary ingredients such as sodium and dyes.
- Patients with diabetes should avoid sugar and ingredients that might cause drowsiness, such as first-generation antihistamines, so that vigilance in monitoring blood glucose is maintained.
What to Remember
There is no short answer to the complex question of how to treat a cough, and each person has unique needs.
- Consult your pharmacist for a nonprescription regimen to meet your individual needs. Describe the cough and discuss other signs and symptoms that may indicate the presence of other illness.
- Combination products may limit flexibility in dosing and increase the risk of side effects; furthermore, medication needs change as symptoms begin to resolve, eg, a cough may persist after fever has resolved.
- Products such as Safe Tussin that are free of sugar, alcohol, dyes, antihistamines, decongestants, and sodium have minimal potential for causing harm or complications in most clinical situations.