A cough is a reflex response to irritation of the airways in the lungs due to a host of factors such as infections, allergens, smoke, dust, too much fluid secretions, and irritant gases. Cough usually occurs due to infection of the upper respiratory tract. However, it could also be a symptom of some other underlying diseases, disorders and conditions. When there is a viral attack on the larynx, trachea and bronchi, they get inflamed due to infection leading to cough. Symptoms appear typically after 2-3 days and may take 1-2 weeks to clear completely. Although more common in winter, coughing knows no seasonal limits. In spring coughing is caused mostly due to allergies. During this time there is chronic cough accompanied by post-nasal drip or wheezing. Winter coughs are usually caused by viral and bacterial infections. Sinus infection can occur at any time of the year and is accompanied by dry cough. Given an infinitely great number of causes of coughing, determining when to seek a doctor’s advice and what cough medications to administer becomes a herculean task. Moreover, a common man is completely ignorant of the medical composition of the drugs and is more likely to choose a product that is advertised a lot by the pharmaceutical companies. This article throws light the cough medicines, their types, composition and some other related facts. With this knowledge, a consumer will be able to make rational decisions and choose the best medicine from the several alternatives available.
Cough medicine is a medicinal drug that is aimed to suppress dry cough or cough up extra mucus. These medicines can be broadly classified into cough suppressants, expectorants, demulcents, decongestants, antihistamines, mucolytics and bronchodilators.
Cough suppressants are medications that suppress the body’s urge to cough and are used for treating dry cough. The active ingredients of cough suppressants are Codeine, noscapine, dihydrocodeine, dextromethorphan, pholcodine and pentoxyverine.
Dextromethorphan or DXM is a non-narcotic derivative of codeine. It works by suppressing the urge to cough by dulling the sensitivity of the central nerves of the respiratory tract that control the cough reflex. It acts centrally in the medulla and raises the threshold for cough stimulus. It treats cough resulting from viral infection of the upper respiratory tract. DXM is not effective in treating cough in case of children. It has several side-effects such as dizziness, sleepiness, fatigue, nausea, constipation, vomiting etc. An overdose of DXM can cause neuropsychiatric problems. DXM should not be used in conjunction with certain medicines such as blood pressure medicines containing MAOI (monoamine oxidase inhibitors).
Benzonatate is a non narcotic drug that suppresses the cough reflex by numbing the lungs and the throat. Its overdose can lead to side-effects such as headache, nausea, dizziness, stomach problems, drowsiness, burning sensation in the eyes, nasal congestion, hallucinations, chest pain and a sensation of chocking. Chewing or sucking on the capsule can make your mouth numb.
Codeine is a vital ingredient of the cough suppressants and has similar effect as dextromethorphan. However, it doesnot cure acute cough in children and is usually not recommended for children.
Noscapine, an OTC is an effective cough suppressant and is widely used in many countries.
Cough suppressants containing opioids should not be administered to kids younger than 6 years of age. It also has negative impacts on the growing fetus, infants, pregnant and breast feeding ladies. It can also cause breathing problems in some people suffering from lung diseases.
Expectorants are a type of cough medicine that increase the amount of mucus made in the lungs making secretions easier to remove by coughing. Expectorants are useful mainly for bronchospasm and pulmonary infection. Their active ingredients are ammonium chloride, senega, ipecacuanha, guaifenesin, ammonia and sodium citrate.
The primary active ingredient of the expectorants is Guaifenesin which thins the mucus to allow the cough to be effective in clearing it out. One of its demerits is that it causes the nose to run more if the cough is produced by nasal mucus production. Other mild side-effects include confusion, drowsiness, slow heart beat, headache, nausea, trouble breathing etc.There are no evidences about the effectiveness of these medications in case of children. However, children below the age of 6 are advised not to use expectorants.
Pseudoephedrine and phenylephedrine are the two commonly used ingredients of decongestants. These are adrenaline derivatives. Decongestants work by constricting the blood vessels in the nasal passage which impedes the mucus production and reduces swelling in the respiratory tract due to increased blood flow caused by the inflammatory action.
Though decongestants dry up a runny nose, they do not work equally well for all persons. Moreover they have certain side-effects such as restlessness, insomnia, irregular heartbeat, cardiac ailments, tremors, hallucinations, stomach upset, nervousness, muscle weakness etc. When decongestants are used with other adrenaline derivatives, the side-effects become more pronounced. They should also not be consumed with blood pressure medicines having MAOI.
Antihistamines reduce histamine release produced during allergic reactions. The active ingredients of these cough medicines are Brompheniramine, Triprolidine, Chlorpheniramine, Doxylamine, Dexchlorpheniramine, Pheniramine etc. These cough medications are intended to inhibit the inflammation and mucus production in thelungs due to endogenous histamine production. Antihistamines are prescribed for allergy patients and patients with bronchospasm. In case of all allergy antihistamines dry up the mucus and provide relief from itchiness and subsequent cough.
Antihistamines are not good for non allergic persons as it dries up their mucus membrane and makes the mouth and nose extremely dry. Antihistamines do not relieve a runny nose in case of viral infection.
These cough medicines suppress coughing by forming a protective layer over the pharyns. These syrups can be administered to children as they have only sucrose and glycerol.
The main ingredients of mucolytics are Acetylcestine or bromhexine.These types of cough medicines make it easier to cough up mucus and are beneficial in case of COPD and chronic bronchitis. A doctor should be consulted if mucolytics are to be administered to kids below 6 years.
They relax the musculature around the lower airway during bronchospasm and allow mucus clearance. Bronchodialtors are adrenaline derivatives and should not be consumed with other adrenaline derivatives.. The main ingredients are albuterol and salmeterol. Mild side-effects include nauseam nervousness, headache, fast heartbeat etc.