Know the Facts

Helping you make informed decisions about your drinking

Alcohol and Other Drugs

Mixing alcohol with other drugs and medications has different effects depending on what the other drug is, how it works and how much of it you take. Alcohol can:

  • increase the side effects of other drugs, such as increasing the risk of gastrointestinal damage after taking painkillers
  • reduce the effect of a medication, including diabetes medication, drugs for HIV/AIDS and antibiotics
  • increase the effect of a drug or medication, if they act on the body in similar ways
  • mask or hide the effect of a drug or medication, if they act in opposing ways

Common symptoms that arise with a dangerous alcohol interaction include:

  • drowsiness
  • dizziness
  • impaired motor control
  • memory problems
  • nausea, stomach cramps or vomiting

These symptoms can appear after as little as one drink. The more medications or drugs that are combined with alcohol, the greater the risk.

Alcohol and other depressants

Alcohol is a depressant, which means it has a sedative effect on the body. When mixed with other sedatives, the effect of both the alcohol and the other drug will be increased. The two will combine to slow down your heart rate and breathing. This can become fatal if too much is taken at once.

Examples of depressants that may have a negative interaction with alcohol
Over the Counter MedicationsAntihistamines; Cough suppressants
Prescription MedicationsPainkillers (morphine, methadone, codeine, percodan, vicoden);
Sedatives (sleeping pills, anti-anxiety pills, muscle relaxants);
Some migraine and anti-convulsive medications
Illicit DrugsHeroin; GHB; Ketamine; Rohypnol; Opium

Alcohol and stimulants

Depressants and stimulants work in opposite ways. Depressants have a sedative effect on your body, while stimulants act to excite the body. When you mix alcohol with a stimulant, the stimulant will hide or mask the effect that the alcohol is having on you. This means you won’t feel as affected by the alcohol as you really are, and this can lead you to make poor decisions such as drinking much more than you usually would and engaging in potentially dangerous behaviours like driving.

Examples of stimulants that may have a negative interaction with alcohol
Common stimulantsCaffeine; Nicotine; Energy drinks
Over the Counter MedicationsPsuedoephedrine; Ephedrine; Diet pills
Prescription MedicationsADHD medication (Ritalin, Adderall); Narcolepsy treatments
Illicit DrugsAmphetamines; Methamphetamines; Ecstasy; Cocaine

Alcohol and cannabis

The effects of mixing alcohol with cannabis can be unpredictable, even at low doses. The mix might cause an increased effect of the alcohol and/or the cannabis, or a completely different reaction altogether. Possible outcomes are:

  • Nausea or vomiting
  • Anxiety or panic
  • Paranoia and other psychotic symptoms
  • Significantly impaired driving ability
  • A reduced ability to control the environment and personal safety

Because the effects of mixing alcohol with other drugs and medications can be so unpredictable, and can in some cases be life-threatening, the safest option if you know you will be taking medications or other drugs is to plan to not drink.


  • National Institute on Alcohol Abuse and Alcoholism. (2007). Harmful interactions: Mixing alcohol with medicines. NIH Publication No. 03-5329.
  • Kaufman, D.W., Kelly, J.P., Wilholm, B.E., et. al. (1999). The risk of acute major upper gastrointestinal bleeding among users of aspirin and ibuprofen at various levels of alcohol consumption. The American Journal of Gastroenterology, 94 , 3189-3196.
  • Mattila, M.J. (1990). Alcohol and drug interactions. Annals of Medicine, 22, 363–369.
  • Sewell, R.A. (2009). The effect of cannabis compared with alcohol on driving. The American Journal on Addictions, 18, 185-193.