ADC Allergy Patient Education
Cough

Your respiratory system works continuously to defend itself against irritation and infection. Layers of mucus (phlegm) lining your nose and airways trap particles such as pollen or dust, and infectious organisms that you breathe in. In response to the irritation or infection, your body steps up production of mucus. Coughing is a protective reflex that occurs when an irritant stimulates one of several cough receptors in your airways. The receptor sends a message to your brain, signaling your body to cough. Coughing helps clear your airways of mucus, taking with it irritants trapped in the sticky secretions.

Usual causes of refractory cough

The four usual causes of refractory cough are 1) post nasal drip 2) sinusitis, 3) asthma, and 4) acid reflux­or any combination of the above. These diagnoses will account for 90% plus of coughs. If you can identify one of the causes that is predominant, focus on that one. Cough is best treated by treating the cause of the cough. For example, if you are coughing because of post-nasal drainage, then controlling the drainage should make your cough go away. lfthere is mucus or a foreign substance in the respiratory tract, the cough should not be hindered, since coughing expels this from your body.

What else can you do for cough?

To ease the cough cycle, try these simple approaches:

	Breathe moist air - Taking a shower or using a humidifier or vaporizer may help loosen mucus.
	Soothe your throat - Sucking on hard candy or cough drops or drinking tea sweetened with honey may help prevent coughing if your throat is dry or sore. Cough drops with menthol or certain herbal teas may be of particular benefit to you.
	Try not to cough - Frequent dry coughing can worsen irritated airways. Try to cough as seldom and gently as possible. Taking frequent sips of liquids may help stifle the cough cycle.
	Breathing exercises for cough - You may be able to help yourself not cough by using "pursed lip breathing." To prevent and interrupt cough. try the following steps:

1. Breathe in gently though your nose, then breathe out through very tight lips.

2. Listen to the sound of air going in and out of the lips. Be certain no air is coming in and out of your nose.

3. If helpful, blow against a finger held up to the lips.

4. Try to prevent coughs by becoming aware of the sensation in your throat that comes before a cough starts and use "pursed lips breathing" immediately.

5. If a cough breaks through. use all your energy to use "pursed lips breathing" to interrupt subsequent cough.

Irritative cough and cough suppressants

Each time you cough, your airways are compressed. A harsh or forceful cough can irritate the lining (membranes) of your airways. Repeated coughing can lead to inflamed membranes, helping to perpetuate your cough. Sometimes cough suppressants are needed to break the cough cycle and to help make you feel generally more comfortable and sleep better. A cough suppressant simply lessens your urge to cough - it does not treat the cause of the cough unless coughing by itself is irritating your airways.

Three medicines are usually effective in suppressing cough. Codeine is an opioid narcotic as is hydrocodone (dihydrocodeinone). The duration of action is similar - about 5 hours. Hydrocodone has a slightly longer plasma half-life. From a practical point of view they are nearly equivalent. Dextromethorphan is the "d" isomer of levorphanol (a narcotic similar to codeine). It seems to act centrally to change the threshold of coughing and is equivalent to codeine in controlled studies. It suppresses coughs about half as effectively as codeine. However, dextromethorphan has little addictive potential due to its low narcotic activity. It generally has fewer side effects, especially sedation and constipation, although it may cause overstimulation or difficulty sleeping in a few people. The doses recommended on the label of many over-the-counter medicines containing dextromethorphan actually provide too little dextromethorphan to do much good, and you should ask your doctor what he or she recommends as the best dose for you.