Methamphetamine use is associated with increased numbers of HIV infections.
Studies indicate that inhaling nitrates depletes a large amount of cells in the immune system, making it difficult for the body to fight infectious diseases.
PCP users may experience memory loss and depression, which may persist for as long as a year after a chronic user stops taking PCP.
The acetaminophen component in Vicodin can on its own put the user at risk of overdose.