Cough medicines aimed at toddlers are about to go behind the counter. But do any of them actually work? Jeremy Laurance investigates

A cough is usually a minor irritation. But when it becomes persistent and keeps you or your children awake at night it can be distressing, debilitating and drive you to desperate measures. At these times, parents turn to cough medicines to soothe their spluttering infants – and in some cases, dose them too heavily.

This is what sparked last week's decision by the Medicines and Healthcare products Regulatory Agency (MHRA) to remove six cough medicines aimed at the under-twos from the open pharmacy shelves, so that parents can be advised about their proper use. But are cough medicines any use? And what is the best way to treat a cough?

A cough is a vital reflex action. It clears the airway of any blockage. It often develops in response to inflammation from a viral infection. It may be a symptom of flu, a cold, asthma, bronchitis or whooping cough. It may also occur in response to certain medicines and, rarely, as a symptom of lung cancer, tuberculosis or heart failure.

Most coughs clear up on their own after a couple of weeks. If you have had one for more than two weeks following a viral infection, it may be time to see your GP.

Coughs are usually labelled dry or chesty. A dry cough is usually felt in the throat as a tickle and does not produce phlegm or mucus. A chesty cough occurs when phlegm is produced in response to the infection. The cough helps clear phlegm from the lungs. But it may also be unproductive, when the passageways in the lungs become inflamed.

There is no way of getting rid of a cough caused by a virus. But you can treat symptoms of the virus with paracetamol or ibuprofen to reduce fever and ease aches – and the cough.

The basic ingredients of all cough medicines are demulcents – glycerine, honey and syrup that coat the throat and ease irritation. Other compounds – suppressants, expectorants and decongestants – have different actions. There is little evidence that cough medicines work, and they only contain small amounts of active ingredients. A soothing drink or boiled sweet may prove just as effective.

Cough suppressants suppress the cough reflex. They include pholcodine, dextromethorphan and antihistamines, and should only be used for dry coughs. Antihistamines can be helpful at night because they assist sleep. Some parents use older allergy medicines, such as Piriton, with their children for this reason (newer antihistamines don't cause drowsiness). Any medicine causing drowsiness should be used with care during the day, and avoided if driving.

Expectorants include ammonium chloride, sodium citrate, guaiphenesin and ipecacuanah, which help bring phlegm up so coughing is easier. They are present in all cough medicines and may help those with chesty coughs.

Decongestants, found in some cough medicines, include pseudoephedrine and phenylpropanolamine. They may help to reduce inflammation and congestion, and can make you feel more alert and awake. But they may raise blood pressure and heart rate.

Antibiotics are of no use in treating viral coughs because they do not kill viruses, only bacteria. The only reason for using them is if you develop a secondary bacterial infection, such as pneumonia. Even so, millions of patients expect antibiotics, and many get them from compliant GPs.

The three key elements for treating a cough, in adults and children, are to have plenty to drink; take paracetamol or ibuprofen to ease the fever, and cough medicine as needed. Some cough medicines contain paracetamol so it is important to check before giving them to children.

A question of safety
By Ben Naylor

*Six cough syrups were removed from general sale last week, they can now only be sold behind the chemist's counter, after consultation with a pharmacist.

*The medicines contain decongestants, cough suppressants, expectorants and antihistamines. The Medicines and Healthcare products Regulatory Agency (MHRA) made the move because five children have died in the past 27 years from accidental overdoses of the medicines.

*The MHRA stresses that the medicines are not unsafe when given at the correct dosages. Spokesman Sara Coakley said: "Nobody should panic. There's nothing wrong with the medicines, it was the way they'd been given. It's precautionary. They are safe."

*The six affected medicines specifically marketed for the under-twos are: Asda Children's Chesty Cough Syrup; Boots Chesty Cough Syrup 1 Year Plus; Boots Sore Throat and Cough Linctus 1 Year Plus; Buttercup Infant Cough Syrup; CalCough Chesty; Children's Chesty Cough.

*Another 59 products, authorised for use in children under two, will also only be sold to parents over the counter. A further 58 products aimed only at children aged two to six will also be taken down. The medicines will return to the shelves when they have been repackaged, removing the dosages for toddlers and offering clearer advice for parents.

*Parents are advised to use products containing paracetamol or ibuprofen to lower a child's temperature. Label advice should be carefully followed. Avoid using more than one remedy at the same time.

*Cough syrups containing glycerol, honey and lemon are safe and will continue to be on general sale.

*For young babies having difficulty feeding, nasal saline drops are recommended. Vapour rubs and inhalant decongestants can also be used to provide relief from a stuffy nose.