Barbiturates are a class of drugs derived from barbituric acidthat act as depressants to the central nervous system. They havesedative and addictive effects.Heroin is an opioid drug made from morphine, a natural substancetaken from the seed pod of the various opium poppy plants. Heroinis highly addictive. People who regularly use heroin often developa tolerance, which means that they need higher and/or more frequentdoses of the drug to get the desired effects.The main difference between the two is what they are made from.Barbiturates are made form barbituric acid and heroin is made fromopium poppy plants.