See the DrugPatentWatch profile for codeine
What does codeine do in the body to reduce a cough?
Codeine is an opioid medicine. When taken by mouth, it can reduce the cough reflex in the brainstem, making the urge to cough feel weaker. This helps some people cough less, especially when the cough is dry or bothersome rather than productive (phlegmy). The effect is symptom control, not treatment of the underlying cause of the cough.
Why does codeine sometimes work poorly (or too well)?
Codeine is converted in the body into morphine by an enzyme called CYP2D6. How much morphine you make affects how strongly codeine works and how strong the side effects can be. People with certain CYP2D6 genetics (and some medications) can make more morphine, leading to stronger opioid effects and higher risk. Others make less, so codeine may do little for their cough.
Does codeine stop a “productive” cough that brings up mucus?
Codeine can suppress coughing even when a cough is bringing up mucus. That can be a concern in conditions where you need to clear secretions, such as some chest infections, because blocking cough may let mucus build up. Clinicians often prefer different approaches depending on whether the cough is dry versus wet.
What side effects can happen with codeine cough medicine?
Common opioid-related side effects include drowsiness, dizziness, nausea, constipation, and slowed breathing in more serious cases. Because it depresses the central nervous system, combining codeine with other sedating substances increases risk.
High-risk situations include mixing codeine with alcohol or other medications that slow breathing (such as many sleep medicines, benzodiazepines, and some other opioids). In some people, breathing problems can become dangerous.
When should codeine cough treatment be avoided or used cautiously?
Codeine needs extra caution or may be avoided in situations that raise the risk of respiratory depression, including significant breathing problems or sleep-related breathing disorders. Also, because of the CYP2D6 conversion issue, codeine can be especially risky for people who are ultra-rapid metabolizers.
Do not give opioid cough medicines to children unless specifically directed by a clinician under appropriate guidance.
What else can help coughing besides codeine?
Non-opioid options vary by cause, but symptom relief can include hydration, honey for cough (for appropriate ages), and addressing triggers like allergies or post-nasal drip. If a cough lasts more than a short time, is severe, or comes with fever, chest pain, wheezing, blood, or shortness of breath, getting medical evaluation is important because cough suppression can delay treatment of the cause.
When to seek urgent care
Get urgent medical help if coughing is accompanied by trouble breathing, bluish lips, fainting, severe sleepiness, confusion, or signs of overdose/over-sedation. These can be medical emergencies with opioid-containing cough medicines.
Sources
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