Cough medicines

Key points about cough medicines

  • There are many cough medicines available from pharmacies and supermarkets but there's no good evidence that cough medicines do help.
  • Cough and cold medicines should not be used in children 6 years of age or younger.
  • Ask your doctor or pharmacist for advice.
Looking at cough and cold shelves in community pharmacy
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Lots of cough medicines are available to buy from pharmacies or supermarkets. They aim to help you cough up the phlegm (mucus) of a chesty cough or to suppress (stop) a dry cough, but there's no good evidence that they work. Cough medicines usually contain 1 or more active ingredients including decongestants or antihistamines for cold symptoms. 

Types of cough medicines

Cough medicines may be formulated in syrups, lozenges, tablets or capsules. Cough medicines aim to work in different ways, depending on their active ingredients. They aim to:

  • Loosen secretions in your airways, so you cough up the mucus. These are called 'expectorants' (eg, guaifenesin) or 'mucolytics' (eg, bromhexine).
  • Reduce congestion and decrease the amount of phlegm (eg, antihistamines – brompheniramine and chlorphenamine). 
  • Suppress the cough reflex which decreases your urge to cough. These are also called 'antitussives' (eg, dextromethorphan and pholcodine) but these products are no longer available in Aotearoa New Zealand.

Dextromethorphan and pholcodine are no longer available in New Zealand

  • Dextromethorphan: Products containing dextromethorphan are no longer being supplied to the New Zealand market (some older stock may remain).
  • Pholcodine: From January 2024 pholcodine will no longer be available in New Zealand due to safety concerns. Use of pholcodine-containing medicines may increase your risk of an anaphylactic reaction (a rare but life-threatening allergic reaction) during surgery.

There is no good evidence that cough medicines help.

  • A review of many studies found no convincing proof that cough medicines reduce cough.  
  • This may be because many coughs get better quickly on their own anyway, so it is hard to tell if the cough medicine has helped or if the cough has simply got better.
  • It has been suggested that the sweet syrup in cough medicines may offer some effect at soothing the throat, rather than the active medicine(s).

Children aged 6 years or younger

Medsafe, a unit of Health New Zealand | Te Whatu Ora, has assessed the safety and effectiveness of cough (and cold) medicines for children and they recommend that parents and carers shouldn't use over-the-counter cough and cold medicines for children under the age of 6 years.

  • This is because there's no evidence that cough and cold medicines work in children.
  • There's also a risk of serious side effects (eg, abnormal heart rate, allergic reactions and reduced consciousness) in children from the active ingredients in cough medicines.
  • Also, there is a greater risk of accidental overdose so cold and cough medicines may cause more harm than good for young children.

Despite the lack of evidence to show that they work, many people still want to use cough medicines. If you are using cough medicines, here are some tips on how to use them safely.


Children between 6 and 12 years of age

For children between 6 and 12 years of age, cough and cold medicines can be used, as there's less risk of serious side effects in older children. Cough medicines for this age group are only available from pharmacies and you will need to speak to a pharmacist.


Taking other medicines

Some ingredients in cough medicines may interact with prescription medicines, so check with your doctor or pharmacist before taking cough medicine.


A cough may be a symptom of an underlying condition

There are many causes of cough, the most common being viral infections such as a cold or the flu. Other common causes include smoking, allergies (eg, hay fever), asthma and bronchitis. Cough may also be a sign of gastro-oesophageal reflux disease (GORD) or may be a side effect of some medicines, eg, ACE inhibitors. 

If you have any of these, you should see your healthcare provider:

  • A persistent, ongoing cough (lasting longer than 3 weeks).
  • A worsening cough.
  • A cough with other symptoms.

Read more about coughs

In most cases, a cough doesn't need to be treated. Mild, short-term coughs are likely to be due to a viral infection that will get better on its own within a few weeks.

You can care for yourself by:

  • resting and drinking plenty of fluids, including lemon and honey drinks
  • sleeping with your head propped up on pillows
  • not smoking, and avoiding smoke
  • using your inhaler if you have asthma
  • taking antihistamines if you have hay fever.

There's currently no evidence that echinacea, vitamin C supplements, garlic capsules, probiotics or steam inhalation has any effect on cough severity or duration.

Honey

Studies have shown that consumption of honey or honey-containing preparations improved respiratory symptoms, including reducing the frequency and severity of cough. Honey can be eaten directly from a teaspoon or added to a drink (eg, warm water with lemon). Lollipops and lozenges containing honey are also available. Honey is only suitable for children aged 12 months and older due to the rare association with infant botulism in children under 1 year of age.

Throat lozenges

Throat lozenges generally contain a combination of anti-inflammatory, antiseptic and local anaesthetic agents or other ingredients, eg, honey, glycerol, eucalyptus oil or menthol. These may temporarily soothe a sore throat and relieve a dry irritative cough, however, there is no evidence that throat lozenges reduce the duration or severity of cough.

Vapour rubs

Chest rubs and vapouriser fluids are no longer recommended because they don’t have any proven benefit AND can be poisonous. They can make young children very sick if they swallow them. The use of camphor blocks or camphorated oil for any purpose is also not recommended. Read more about vapour rubs.

Ivy leaf extract

“Bronchial syrups” containing ivy leaf extract (Hedera helix) are classified as dietary supplements in New Zealand. There is some evidence that the use of ivy leaf, for the treatment of acute upper respiratory tract infections in adults and children, can reduce cough severity and frequency. 

Zinc

There is some evidence that zinc lozenges may reduce the duration of cough in adults if used within 24 hours of symptom onset. Zinc lozenges can have an unpleasant taste. Read more about zinc and zinc supplements. 

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Credits: Sandra Ponen, Pharmacist, Healthify He Puna Waiora. Healthify is brought to you by Health Navigator Charitable Trust.

Reviewed by: Angela Lambie, Pharmacist, Auckland

Last reviewed: