What happens when you take alcohol with codeine?
Codeine is an opioid painkiller that is relatively weak on its own. The liver converts part of it, using an enzyme called CYP2D6, into morphine, which is a much stronger opioid. How efficiently this happens varies a great deal from person to person, which matters when alcohol enters the picture.
- Both substances depress the brainstem. Alcohol and the morphine made from codeine both act on the part of the brainstem that controls breathing, slowing the rate and depth of each breath.
- Their effects add together. Alcohol boosts the calming neurotransmitter GABA while dampening stimulating signals; codeine's morphine metabolite activates mu-opioid receptors. The combined sedation and respiratory slowing is greater than either alone.
- Breathing can stop. Together they can suppress breathing toward apnea, a risk that is highest during sleep, when the body's drive to breathe is already lower.
- Fast metabolizers are more exposed. People who are CYP2D6 ultra-rapid metabolizers turn codeine into morphine quickly and in larger amounts, so an ordinary dose can act like a much stronger opioid, narrowing the margin of safety when alcohol is added.
- Sedation and impairment deepen. Beyond breathing, the pair causes pronounced drowsiness, clouded thinking, and loss of coordination, plus more nausea, low blood pressure, and falls, especially in older adults.
Why is this important?
Codeine has long had a reputation as a gentle opioid, and that reputation can lead people to underestimate it. Because of the genetic variation in how it is metabolized, some people get morphine-like effects from a standard dose. Add alcohol, and the range between an ordinary dose and a dangerous one becomes much narrower.
Regulators treat this seriously. The FDA prescribing information for codeine carries a boxed warning stating that using opioids alongside other CNS depressants, including alcohol, may result in profound sedation, respiratory depression, coma, and death. Codeine products also carry warnings about the ultra-rapid metabolizer risk.
Codeine is frequently sold as a liquid cough preparation. Liquids are easy to take more of than intended, and they are sometimes consumed in larger amounts than the cough indication calls for. Mixing codeine cough syrup with alcohol, including recreational patterns such as "lean" or "purple drank," has caused deaths, particularly among young adults.
Some people are at especially high risk: ultra-rapid metabolizers who do not know their status (there is no routine testing before prescribing), older adults with less respiratory reserve, and people with sleep apnea, COPD, or asthma. Anyone also taking benzodiazepines, sleep aids, muscle relaxants, gabapentinoids, or sedating antihistamines faces cumulative depressant effects.
What should you do?
The core principle is simple: codeine and alcohol do not mix, in any form, throughout the entire time you are taking codeine.
Before you start codeine: Tell your doctor or pharmacist about your alcohol use honestly, so they can assess your risk. Ask whether any of your other medicines are also sedating, and read the labels of any cough or combination products you keep at home to see whether they contain codeine.
Every day while taking it: Avoid all alcohol. This covers beer, wine, and spirits, and also alcohol hidden in liquid medicines, tinctures, and some syrups. Treat codeine cough syrups as the serious medicines they are and never combine them with alcoholic drinks. If you notice excessive drowsiness, slow or shallow breathing, blue lips or fingertips, pinpoint pupils, confusion, or someone who cannot be woken, call emergency services right away and give naloxone if it is available.
After you stop: Codeine and its active morphine metabolite linger for a while after the last dose. Wait until the medicine has fully cleared before drinking alcohol again; your pharmacist can tell you how long to allow for your specific product. If codeine was prescribed for short-term pain, plan for an alcohol-free stretch covering the whole course.
Which specific products are affected?
Codeine comes in many forms. It is sold as tablets on its own and combined with acetaminophen (the Tylenol with Codeine range, often labeled #2, #3, or #4) or with aspirin. Liquid codeine is usually a cough syrup, including codeine-promethazine and codeine-guaifenesin combinations.
Brand and product names include Tylenol with Codeine, Codeine Contin (extended-release), Solpadeine, Co-codamol, Empirin with Codeine, Phenergan with Codeine, and various international formulations. Promethazine-with-codeine cough syrup has been a notable target of recreational misuse. Pseudoephedrine-codeine-guaifenesin combinations also exist.
Combination products containing acetaminophen carry an extra concern, because alcohol also increases acetaminophen's strain on the liver, so the same drink raises both the breathing and the liver risk at once.
On the alcohol side, the caution applies to every source of ethanol: beer, wine, spirits, and liqueurs; alcohol used as a solvent in some liquid medicines and cough syrups; herbal tinctures; mouthwash if swallowed; hand sanitizer if ingested; and cooking alcohol that has not fully cooked off. Even small amounts add to the interaction.
The science behind it
The StatPearls clinical reference on codeine states plainly that "concomitant use of codeine with other known sedatives, such as alcohol or benzodiazepines, can significantly increase the risk of adverse and possibly dangerous effects," and that ultra-rapid metabolizers "may have life-threatening or fatal respiratory depression at a therapeutic dose."
This is reflected in regulation. The FDA codeine sulfate prescribing information includes a boxed warning that concomitant use of opioids with benzodiazepines or other CNS depressants, including alcohol, may result in respiratory depression, profound sedation, coma, and death.
Forensic and pharmacological evidence supports this picture. A 2014 analysis of codeine-related deaths found that CYP2D6 metabolism and concurrent CNS depressants such as alcohol and benzodiazepines shaped the codeine and morphine levels seen in fatal cases, reinforcing that the morphine produced from codeine is the active driver of its opioid effect (PMID 24747667, 2014).
All of these sources point the same way: the mechanism is well established additive CNS and respiratory depression, with the morphine produced from codeine the active driver, and the danger heightened by the wide person-to-person variation in CYP2D6 metabolism.
Frequently Asked Questions
Is one drink really a problem with codeine?
There is no amount of alcohol that is established as safe with codeine. Because individual sensitivity varies so widely, even a small amount can add meaningfully to sedation and slowed breathing. The safest course is none.
What about codeine cough syrup, not tablets?
The same caution applies. Codeine in a cough syrup is the same opioid, and these liquids have been involved in many alcohol-related deaths. Do not combine any codeine cough preparation with alcohol.
How long after my last dose can I drink?
Wait until the codeine and its morphine metabolite have fully cleared your system, which takes longer than people expect. Ask your pharmacist how long to allow for your specific product before having any alcohol.
What are the warning signs of an overdose?
Excessive drowsiness or inability to wake, slow or shallow breathing, blue lips or fingertips, pinpoint pupils, and confusion. These are medical emergencies call emergency services and use naloxone if it is available.
Why are some people at higher risk than others?
People who are CYP2D6 ultra-rapid metabolizers convert codeine to morphine quickly, so a standard dose can act much more strongly. Most people do not know their status because there is no routine testing, which is part of why combining codeine with alcohol is unpredictable.
Does it matter if I also take other sedating medicines?
Yes. Benzodiazepines, sleep aids, muscle relaxants, gabapentinoids, and sedating antihistamines all add to the depressant effect, compounding the risk. Tell your prescriber about everything you take.
Key takeaways
- Codeine and alcohol are both CNS depressants; together they can cause dangerous or fatal slowed breathing.
- The FDA prescribing information carries a boxed warning against combining opioids with alcohol or other CNS depressants.
- The risk is amplified for CYP2D6 ultra-rapid metabolizers, who convert codeine to morphine quickly and usually do not know their status.
- The caution covers all codeine products, including cough syrups that many people do not treat as serious medicines.
- Avoid alcohol throughout codeine treatment and until the medicine has fully cleared; ask your pharmacist how long to wait.
- Know the emergency signs slow breathing, blue lips, pinpoint pupils, unresponsiveness and seek help immediately.