Doping is an area of ongoing public, legal, and medical debate and in recent years it has been reported to be connected with many sports including athletics, cycling, body building, soccer, and swimming. Ethical issues related to doping include the honesty of the sports competition and the safety of drugs and other methods applied to improve the physical performance. These issues are of increasing interest and importance since drugs on the prohibited list are easily accessible by medically uncontrolled means such as the Internet.

According to the International Olympic Committee (IOC)1doping consists of (1) the administration of substances belonging to prohibited classes of pharmacological agents and/or (2) the use of various prohibited methods. There are five prohibited classes of substances: stimulants, narcotics, anabolic agents, diuretics, and peptide and glycoprotein hormones and their analogues (table 1). Prohibited methods include blood doping and pharmacological, chemical and physical manipulation.

Several respiratory drugs are included in the list of prohibited substances unless they are administered by inhalation. This paper reviews the current literature concerning the effects of respiratory and some other drugs on the respiratory system in the broadest sense—that is, from the respiratory controllers to the respiratory muscles and the lungs themselves. We will focus on the effects in athletes and healthy trained and untrained subjects but, where appropriate, we will also refer to studies in patients, to animal studies, and to studies in peripheral skeletal muscles.