Is it worth using medicine to loosen and cough up phlegm (expectorants)?

“Expectorants” is the medical term used to describe medications that

• increase the production of mucus in the bronchi of the lungs or
• loosen thick, sticky mucus in the bronchi.

This is meant to make it easier to cough up the phlegm and relieve the cough. Based on the research in this area so far, it isn’t clear whether these medications actually help in the treatment of acute bronchitis. If used at all, expectorants should only be used if the mucus that is produced can be coughed up.

What do cough suppressants (antitussives) do?

Cough suppressants (antitussives) don’t act upon the inflamed mucous membranes in the bronchi. Instead, they aim to suppress the urge to cough, so they are rarely used in the treatment of acute bronchitis. Typical examples of suppressants include codeine and dextromethorphan.

Cough suppressants should only be used in the treatment of severe dry coughs, for a maximum period of two weeks – and especially if the cough is bothering you at night and disrupting your sleep. They shouldn’t be used in the treatment of productive (“wet”) coughs: If the urge to cough is suppressed, the phlegm won’t be coughed up and out of the bronchi.

Besides, there haven't been any studies on the benefits and drawbacks of cough suppressants in the treatment of acute bronchitis. The few studies done so far have only looked into their effectiveness in the treatment of simple common colds, throat inflammations and sinusitis. They found the following:

• Codeine doesn’t help in the treatment of acute coughs in adults, nor in children and teenagers, who have a cold. Children under the age of twelve generally shouldn’t be prescribed codeine or codeine-containing medications. The same is true for breastfeeding mothers.
• Dextromethorphan can somewhat soothe coughs associated with upper respiratory tract infections in adults, at least for a short while after taking it. People who have lung conditions such as asthma or COPD shouldn’t take dextromethorphan. The possible side effects include dizziness and gastrointestinal (stomach and bowel) problems.

Codeine has to be prescribed by a doctor, whereas medications containing dextromethorphan are also available from pharmacies without a prescription.

How effective are herbal products?

Various herbal products are available for the treatment of acute bronchitis, some of them based on combinations of different active ingredients. Examples include Pelargonium, primrose, thyme, eucalyptus and ivy extracts. Studies on these products suggest that they can somewhat soothe acute bronchitis coughs and make it easier to cough up phlegm. The possible side effects include stomach and bowel problems. Statutory health insurers in Germany generally don’t cover the costs of these products.

Other herbal products – such as those used in traditional Chinese medicine (TCM) – have hardly been tested in high-quality studies. So it isn’t known whether they can help. But they, too, can have side effects.

Do bronchodilators work?

Bronchodilators (medications to widen the airways) are normally used in the form of an inhaler for the treatment of lung conditions that cause the airways to narrow, such as asthma and COPD. They are not effective in the treating of acute bronchitis in which the airways aren’t narrowed, and shouldn’t be used.

Which medications can help relieve other symptoms?

Especially at the start of acute bronchitis, an accompanying cold or flu can cause symptoms such as a headache, sore throat, earache or joint pain. Medication that relieves pain and reduces fever can lead to an improvement in these symptoms. Examples include paracetamol (acetaminophen) and non-steroidal anti-inflammatory drugs (NSAIDs), e.g. ibuprofen and acetylsalicylic acid – the drug in medications like Aspirin.

These drugs are available from pharmacies without a prescription. They come in the form of tablets, suppositories and syrups.

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Acetylsalicylic acid isn’t suitable for children under the age of twelve years who have a viral infection with a fever. This is because it can lead to severe brain and liver damage (Reye's syndrome), although that is rare.

What else can you do?

Particularly in the first few days of the illness, it is important to take the time to rest, and avoid strenuous physical activity and sports. People are often advised to drink a lot of fluids to help loosen the mucus in their bronchi (lungs). But there are no suitable studies on whether “drinking a lot of fluids” is better than “drinking normal amounts,” or may even be harmful.

Honey can soothe coughs – either eaten on its own or stirred into a warm drink. Studies in children suggest that honey can soothe coughs associated with upper respiratory tract infections. But children under the age of one shouldn’t eat honey because they sometimes react sensitively to certain bacteria in it.

Smokers who have acute bronchitis can go easy on their lungs by trying not to smoke.

Why aren’t antibiotics recommended?

Antibiotics are drugs that kill or prevent the growth of bacteria. Acute bronchitis is usually caused by viruses, though, so antibiotics won’t help.

Many studies have shown that antibiotics hardly affect the course of the illness. In the studies, antibiotics reduced the duration of the cough by half a day on average. But they also caused side effects such as diarrhea, nausea or a skin rash in about 3 out of 100 people.

Also, the more often antibiotics are prescribed, the more likely it is that bacteria will become resistant to them. As a result, antibiotics may no longer be effective against certain bacteria. So antibiotics aren’t recommended for the treatment of acute bronchitis.

Some people have a higher risk of acute bronchitis leading to more serious complications (e.g. pneumonia), for instance due to a weak immune system, a severe lung or heart condition, or old age. Treatment with antibiotics may then be a good idea, in order to prevent complications.

Sources

• Becker LA, Hom J, Villasis-Keever M et al. Beta2-agonists for acute cough or a clinical diagnosis of acute bronchitis. Cochrane Database Syst Rev 2015; (9): CD001726. [PMC free article: PMC7078572] [PubMed: 26333656]
• Bundesinstitut für Arzneimittel und Medizinprodukte (BfArM). Codein: Überprüfung des Nutzen-Risiko-Verhältnisses von codeinhaltigen Arzneimitteln zur Behandlung von Husten bei Kindern und Jugendlichen. 2022.
• Chalumeau M, Duijvestijn YC. Acetylcysteine and carbocysteine for acute upper and lower respiratory tract infections in paediatric patients without chronic broncho-pulmonary disease. Cochrane Database Syst Rev 2013; (5): CD003124. [PMC free article: PMC11285305] [PubMed: 23728642]
• Deutsche Gesellschaft für Allgemeinmedizin und Familienmedizin (DEGAM). Akuter und chronischer Husten (S3-Leitlinie). AWMF-Registernr.: 053-013. 2021.
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