The Dangers of Combining Codeine and Weed

3 min read · 6 sections

Marijuana and opiates, including the prescription drug codeine, are two of the most accessible substances in the United States. The use of these two drugs together can cause interactions that are extremely harmful to the body. Here we will discuss the effects of combining codeine and marijuana. 

What are the Effects of Codeine?

Codeine is an opioid drug used to relieve mild to moderate pain and reduce coughing. It can be prescribed in a tablet form, but it is also commonly found in prescription-grade cough syrups or in combination with acetaminophen (Tylenol). 

Although codeine is less potent than other opioid drugs, it still acts on the brain in a similar fashion to provide the user with feelings of euphoria and relaxation. And like other opioids, codeine produces adverse side effects that can include:1 

  • Drowsiness.
  • Lightheadedness.
  • Dizziness.
  • Sedation.
  • Shortness of breath.
  • Nausea.
  • Vomiting.
  • Sweating.
  • Constipation.

Despite its potentially harmful effects, the abuse of prescription cough medicines containing codeine has become popular among teens and young adults, especially those who reside in the southern United States. 

It has even become glamorized by some hip-hop artists who mix the medicine with sugary soda and candy to decrease the bitter taste, creating an addictive concoction referred to as “syrup” or “sizzurp“.2 Drinking this mixture is extremely dangerous, as demonstrated by the number of people who have been recently hospitalized after consuming this drink. 

What are the Effects of Marijuana?

Marijuana, also commonly referred to as weed, grass, herb, pot, reefer, bud, dope, and Mary Jane, is a mind-altering drug produced by the cannabis plant.3 The chemical tetrahydrocannabinol (THC) found in marijuana is the principal ingredient responsible for its psychoactive effects. 

In addition to feelings of euphoria, marijuana use can also produce effects that include relaxation, heightened sensory perception, increased appetite, anxiety, paranoia, hallucinations, increased heart rate, reduced blood pressure, difficulty concentrating, and impaired memory.3 

Take Our Marijuana Addiction Self-Assessment

Take our free, 5-minute marijuana addiction self-assessment below if you think you or someone you love might be struggling with a marijuana dependency. The evaluation consists of 10 yes or no questions that are intended to be used as an informational tool to assess the severity and probability of a marijuana use disorder. The test is free, confidential, and no personal information is needed to receive the result.

The Dangers of Mixing Codeine and Marijuana

Although some people may think that codeine is relatively harmless compared to other opioids due to its widespread availability, at a high enough dose codeine can lead to respiratory failure, coma, and even death.4 

This risk is especially high when codeine is combined with other central nervous system depressants such as alcohol or other opioids. Although technically not classified as a depressant drug, certain compounds present in marijuana can depress the central nervous system and cause side effects such as lethargy and low energy.5 

The depressant properties of marijuana make it extremely dangerous to use in combination with codeine because it may cause an additive effect, resulting in exacerbated suppression of the central nervous system. 

Studies have shown that the combined use of marijuana with opioids such as codeine results in elevated symptoms of anxiety and depression compared to use of the opioid alone.6 The combined use of marijuana and codeine also increases the likelihood of substance use problems. Research has shown that marijuana users are much more likely to misuse prescription opioids and develop a prescription opioid use disorder compared to nonusers.7 

Like other opioid drugs, codeine has a high potential for abuse. As the frequency of codeine use increases a tolerance to the drug develops, increasing the dose needed to experience the desired effects. This pattern will eventually lead to physical dependence, which can be especially difficult to deal with if you also use marijuana. 

Findings from a recent study suggests that 30% of marijuana users suffer from dependence and will experience withdrawal symptoms when not taking the drug.8 

Treatment Options

If you or someone you care about is struggling from the effects of codeine and marijuana abuse, please reach out to a professional drug addiction rehab center today to learn about the available polydrug addiction treatment programs that can be personalized to your specific needs. 

Due to the harmful and uncomfortable symptoms associated with codeine withdrawal, the first step on your road to recovery will likely be a medically supervised detox that can address any complications arising during the detoxification process.

Find Codeine Treatment Near You


  1. Peechakara, B.V., & Gupta, M. (2019). Codeine. StatPearls [Internet], Treasure Island, FL: StatPearls Publishing.
  2. Laskowski, L., & Nelson, L.S. (2014). Case Studies in Toxicology: Sippin’ on Some “Sizzurp”. Clinician Reviews, 46(11), 501-504.
  3. United States Drug Enforcement Administration. (2017). Marijuana/Cannabis. Drugs of Abuse: A DEA Resource Guide.
  4. Roxburgh, A., Hall, W.D., Burns, L., Pilgrim, J., Saar, E., Nielsen, S., & Degenhardt, L. (2015). Trends and characteristics of accidental and intentional codeine overdose deaths in Australia. The Medical Journal of Australia, 203(7), 299.
  5. Mayo Clinic. (2017). Marijuana.
  6. Rogers, A.H., Bakhshaie, J., Buckner, J.D., Orr, M.F., Paulus, D.J., Ditre, J.W., & Zvolensky, M.J. (2019). Opioid and Cannabis Co-Use among Adults With Chronic Pain: Relations to Substance Misuse, Mental Health, and Pain Experience. Journal of Addiction Medicine, 13(4), 287-294.
  7. Olfson, M., Wall, M.M., Liu, S.M., & Blanco, C. (2018). Cannabis Use and Risk of Prescription Opioid Use Disorder in the United States. The American Journal of Psychiatry, 175(1), 47-53.
  8. Hasin, D.S., Saha, T.D., Kerridge, B.T., Goldstein, R.B., Chou, S.P., Zhang, H., … & Grant, B.F. (2015). Prevalence of Marijuana Use Disorders in the United States Between 2001-2002 and 2012-2013. JAMA Psychiatry. 72(12), 1235-1242.
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