Drug abuse is still a major public health problem. Although the use of some older drugs, such as opioids (heroin) and cocaine, is slowly decreasing, and mortality rate is declining, today we are facing socially vulnerable and excluded groups of former or current drug users. Cannabis is the most widely-used drug in Europe. Recent studies have shown that consumption of cannabis during adolescence can lead to long-term changes in brain function. An alarming issue on drug market are new psychoactive substances which are trying to imitate prohibited drugs. They are classified into several groups: synthetic cathinones, fentanilamins, piperazines, tryptamines, synthetic cannabinoids and other substances that can not be classified in any of these groups. The new, particularly powerful synthetic substances are synthesized in illegal laboratories and sold on the Internet. Only in 2013, 81 new drugs were detected and now a system for early detection monitors more than 350 psychoactive substances suspected to be toxic or deadly. Therefore, this system is under great pressure. European Monitoring Centre for Drugs and Drug Addiction (EMCDDA) is the central source and a valid body dealing with drug-related issues in Europe. Early Warning System on New Psychoactive substances of EMCDDA regularly publishes the list of newly discovered substances. The profile of the substance can be found in EDND basis (European information system and database on new drugs). Symptoms and signs of intoxication with new psychoactive substances are diverse, and death cases have been reported. Intravenous drug use, in particular synthetic cathinones, is associated with soft tissue infections and increased risk of infection with HIV and hepatitis viruses.