Can I take codeine if I have asthma?

Taking codeine with asthma is generally not recommended and is often contraindicated, especially if you have acute, severe, or uncontrolled asthma.¹²³⁴

Key Risks

• Respiratory Depression: Codeine is an opioid that slows down the central nervous system and decreases your drive to breathe. In people with asthma or compromised lung function, even normal doses can lead to dangerously slow or shallow breathing.¹²³⁴
• Asthma Exacerbations: Opioids can cause histamine release in the body, which may trigger airway narrowing, flushing, or a pseudo-allergic reaction that worsens asthma symptoms.¹²
• Masking Dangerous Symptoms: Codeine suppresses the cough reflex. While sometimes tried for persistent dry coughs, blocking the cough reflex in an asthmatic airway can hide a worsening respiratory infection or severe bronchospasm.¹²³⁴
• Never During an Attack: Codeine should never be used during an acute asthma attack.¹

What You Should Do

• Consult your doctor or pharmacist before taking codeine or any codeine-containing medication (such as certain linctuses or combination painkillers) if you have asthma.¹²³
• Review safer alternative treatments for pain or cough that do not depress breathing by checking official patient information on the NHS Codeine Guide or consulting your GP.¹
• If you experience shortness of breath, long pauses between breaths, or wheezing after taking codeine, seek emergency medical help immediately.¹²

• General Precaution: Codeine should be used with caution—or avoided—if you have asthma. Because codeine is an opioid that depresses the central nervous system, it can depress the respiratory drive and suppress the cough reflex, which can be dangerous if you need to clear your airways during an asthma flare-up.¹
• Respiratory Depression Risk: Opioids can slow down breathing and cause bronchi to constrict or suppress the natural ability to cough up mucus, potentially worsening breathing difficulties in people with compromised lung function.
• Official Guidance: Health bodies and guidelines (such as the Northampton General Hospital Formulary / BNF notes) explicitly note that codeine is not recommended for adolescents or individuals with breathing/respiratory problems.¹
• Cough Suppressants & Asthma: If you are coughing due to asthma, suppressing the cough with codeine does not treat the underlying airway inflammation or bronchospasm. Instead, asthma-related coughs require proper management with prescribed inhalers (such as preventers and relievers) rather than over-the-counter or generic opioid cough suppressants.
• Next Steps:
  1. Consult your GP, asthma nurse, or pharmacist before taking any medication containing codeine.
  2. Review your current asthma action plan or reach out to Asthma + Lung UK for guidance on managing persistent coughs safely.
  3. Seek urgent medical attention if you experience increased breathlessness, wheezing that does not respond to your reliever inhaler, or signs of respiratory distress.

You should be cautious about taking codeine if you have asthma. Codeine can affect your breathing, and in some people it can cause respiratory depression (slowed or shallow breathing).

Whether it is safe depends on how severe your asthma is, how well controlled it is, and the type of codeine medication.

Why codeine can be risky with asthma

• Slows breathing: Codeine is an opioid that can suppress the respiratory system.
• Can worsen breathing problems: This is particularly concerning if you have poorly controlled asthma.
• Can cause drowsiness: This may make it harder to recognise worsening breathing difficulties.

Can you take it if your asthma is controlled?

Sometimes, yes, but only if a doctor has assessed you and considers it appropriate. UK medicine guidance advises that codeine may be used cautiously in people with controlled asthma, but should not be taken during an acute asthma attack. www.medicines.org.ukwww.medicines.org.uk

My advice: Speak to a pharmacist or doctor before taking it, even if your asthma is usually mild.

If you've already taken codeine and develop slow or shallow breathing, severe breathlessness, or difficulty staying awake, call 999.

Can I ask you three things?

1. Is your asthma mild, moderate or severe?
2. Is it currently well controlled, or have you been wheezing or needing your blue inhaler more than usual?
3. What codeine are you considering taking, and what strength (e.g. 15mg, 30mg or co-codamol)?

I can help you understand the risks based on your answers.