The multiplier effect, or synergistic effect, of alcohol refers to the combination of the effect of alcohol with one or more drugs that is greater than the sum of the individual effects of each substance, according to the University of Notre Dame. One example from the Getting Them Sober Foundation shows that one joint of marijuana combined with alcohol seems like 10 beers instead of one beer.
The multiplier effect means certain substances more than double the effects of one drink. Instead of alcohol's impairment plus cocaine's stimulant effect, the combination of the two drugs can increase someone's heart rate by three to five times more than either substance alone, according to Santa Clara University's wellness center.
Synergistic effects of alcohol with drugs can have multiple symptoms. Santa Clara University reveals alcohol combined with the drug Ecstasy increases dehydration. Marijuana suppresses the body's sensation of nausea, making an alcohol overdose much more likely. Mixing narcotics and alcohol may result in higher intoxication levels, coma and even death. Combining sedatives with alcohol can cause depression, dizziness, forgetfulness, coma and death.
A study published by the University of Texas showed that the effects of tobacco and alcohol were not multiplied. The study did determine that people who drank first did not smoke tobacco as readily.