A person under the influence of alcohol can do all sorts of bad things but what more if someone is under the influence of drugs? Some of the drugs most often associated with this term include alcohol, methaqualone, barbiturates, benzodiazepines, cocaine, amphetamines, and opium alkaloids. Aside from the ill effects it can cause to the drug user, people around him/her are also put at risk. Read more about drug abuse and how drug rehab can help before it's too late.