Expectorants which are widely prescribed by the physicians for cough relief do too little good for the patients but a lot for the companies who sell them. Patients take expectorants, as they are blissfully unaware of zero therapeutic value of these products.

The gross annual sales of expectorants account for Rs 243 crore in the country. The top product is Benadryl, long considered the king of expectorants with the strongest brand recall even among the lay public, and has an annual sales of Rs 36.14 crore. Benadryl has an annual growth rate of 4.25 per cent.

Glenmark's Ascoril with a turnover of Rs 14.73 crore is the number two brand in the market while Piriton Expectorant of Glaxo is in the third position with Rs 11.30 crore sales per annum.

Expectorants are claimed to promote expulsion of bronchial secretions, but there is no evidence that any drug can specifically facilitate expectoration, according to a leading medical expert. The assumption that sub-emetic doses of ammonium chloride, ipecacuanha promotes expectoration is a myth. However, a simple expectorant mixture may serve a useful placebo function.

Demulcent (Substances that soothe irritated tissue, particularly mucous membranes) cough preparations contain soothing substances such as syrup or glycerol and certainly many patients believe that they can relieve a dry irritating cough. Steam inhalation is a good expectorant therapy in bronchiectasis and some chronic bronchitis.

Most of the expectorants contain ammonium chloride, sodium citrate, guaiaphenisin and potassium iodide. These are thought to reduce the viscosity of mucous and increase the secretions of the respiratory tract. Whether these cough preparations really do any speedy recovery or just relieve symptoms, is a question often asked by several medical experts.

Says Dr Chandra M Gulhati, editor of Monthly Index of Medicine Specialties India, "With the probable exception of cough expectorants containing ambroxol or bromhexine, none of the expectorants being marketed in India is doing any good to any patient. There are three major problems with the so-called expectorants. Firstly, the ingredients claimed to be helping expectoration simply do not do so. Secondly, even if they were to be effective, the dose employed is sub-therapeutic. Thirdly many formulations contain anti-histamines (eg, Zeet Expectorant of Alembic) that dry the mucous instead of liquefying it. Thus these products contain ingredients, which nullify the effect of each other which is a novel way of making money. None of the "expectorants" sold in India are allowed to be marketed in the western countries such as the UK."

A leading allergy specialist told Pharmabiz.com that there is no irrefutable evidence in medical literature that expectorants help expulsion of mucous. "If there is no harm due to the usage of the expectorant," then why not? says allergy specialist Dr Wiqar Shaikh. Says he, "Plain expectorants have little value in treatment. Mixtures of expectorants containing bronchodilators may be of help, if used judiciously. It is important to find out the root cause of mucous formation and strike there with the right medicine whether for asthma or anything else. In case of a patient with persistent dry cough, cough suppressants (such as codeine or dextromethorphan) may be given so that the patient is not drained of his energy. There are however, medical practitioners and quacks who prescribe these medicines by just reading only the literature offered by representatives of pharma companies and without really going through books and journals."

"When you are having chest infection or bronchopulmonary infection, cough is a symptom. The basic pathophysiology has to be treated with an anti-bacterial. If you give them only an expectorant, cough will not stop," says an industry source.

Says a medical advisor of a pharma company, "In pharmaceutical industry, products which have zero effect on patients will not last at all. Expectorants definitely reduce viscosity. They may not have a dramatic effect on patients, but can work as adjuvants with antibiotics, ie, an antibiotic will have to be used along with the expectorant. This does not mean we should discard expectorants. Some of these products may have some good effect. Many things happen in real clinical practice. Like for instance, a doctor might prescribe a steroid for conjunctivitis when it is not needed. The doctor's justification is that the patient feels better immediately and after a couple of days he is taken off the steroid and put on normal medication. This way the patient is happy and comfortable. We have to see what is practical."

According to Dr Arun Bal of Association for Consumers' Action on Safety and Health (ACASH), there is no medical evidence with double blind controlled studies to say that expectorants relieve sputum. Even a simple vapour inhalation can relieve sputum. The efficacies of all expectorants, many of which are over-the-counter medications, are doubtful. Cough is a symptom, which needs to be investigated not just treated with medicines. These expectorants may not be harmful, but they are not useful.

Dr Bal suggested that the DCGI should subject all the expectorants to a proper check. "The claims of pharma companies need to be checked. It should also be checked whether proper trials have been done before marketing. I don't know whether the DCGI has the facility or the willingness to do all this."

A manager with a leading Indian company says that expectorants have a job to perform in productive cough just as anti-tussives are used to suppress dry cough. Expectorants can never be said to have placebo function, he said.

Says a senior marketing manager with a multinational company, expectorants have an indirect action through bronchodilation. It may not be proper to say they don't work. They may work by increasing saliva and respiratory fluid and facilitating sputum. There is no direct action, however.

Says another marketing executive, "There is enough evidence to show their utility in clinical settings worldover. However, a large number of preparations contain only sub-therapeutic dosages for action to happen. Also some products contain an expectorant along with a cough suppressant which is antithesis of the concept as the two will nullify each other's action."

According to Indian Drug Review, they are of two types: reflex acting and directly acting. Potassium iodide, ammonium chloride and ipecacuanha are reflex acting while potassium and sodium citrate, vasaka, guaiphenisin, terpinhydrate, balsam of tolu, and guaicol.

Mucolytics are drugs which cause liquefaction of tenacious or mucopurulent sputum eg., bromhexine, acetyl cysteine, and pancreatic dornase.

Anti-tussives are used to suppress non-productive or dry cough and they act on the cough centre to inhibit stimulation of receptors in throat and respiratory passages. Principal anti-tussives are codeine, noscapine, pholcodeine, carbetapentane, dextromethorphan, pipazethate, chlophendianol, ethylmorphine, morphine and oxladin. Dextromethorphan is an anti-tussive which exerts its action in CNS to elevate the threshold of coughing. Its potency is equal to that of codeine.

"When you are having chest infection or bronchopulmonary infection, cough is a symptom. The basic pathophysiology has to be treated with an anti-bacterial. If you give them only an expectorant, cough will not stop," says an industry source.

However, a senior regulatory official said that expectorants are simple to make, require no great technology, and hence there were hardly any regulatory complaints made against these products. He averred such products did work.

According to this regulatory official, there could be some problem with these products once manufacturers try to do permutations and combinations with the ingredients. The result could be that some ingredient becomes sub-therapeutic. "If you can bring 15 such cases to our notice, we will have a look at them with an open mind," he assured.

According to an industry source, expectorants work by increasing saliva and respiratory fluid, facilitating sputum. "There is no direct action, however. Expectorants have been in use for a long period abroad. However, the documentation of its efficacy is very poor."