This thesis examines interactions between antiretroviral HIV treatment and recreational drugs. It will present data on how interactions can occur and be prevented. For over 30 years, HIV infection has continued to spread worldwide despite medical advances. Both the number of infections and deaths from the disease are still increasing. There is also prevalent recreational drug use, and historical data links new HIV infections to psychotropic substance use. In some patients, dangerous and even fatal interactions have been observed between treatments and recreational drugs. These drugs may not only cause adherence issues but also treatment failures. More research is needed on this important phenomenon, though science has revealed and prevented some dangerous interactions.