Substance abuse and international travel.

Travel for both business and pleasure can be a risk factor for substance abuse problems, for clinical deterioration in those with chemical dependence, and for relapse when an addiction has been in remission. Sedatives, opioids and alcohol can complicate many of the physiologic adjustments mandated by modern jet travel, such as adaptation to different altitudes, climates, and time zones. Additionally, substances of abuse can result in a deterioration of many clinical conditions during travel, and they can precipitate other medical problems while underway, including motion sickness, heat-related illness and diarrheal disease. Drugs and alcohol are crucial factors in both serious accidents and legal difficulties while traveling. Finally, involvement with drugs as well as close and intimate liaison with drug abusers and their consorts has associated with it a high degree of risk for exposure to serious infectious diseases worldwide.