Inhalants such as nitrous oxide, halothane, enflurane and sometimes ether are used in medicine to produce anesthesia for surgery. The anesthesiologist has to keep enough anesthetic in the patient to prevent pain and keep the patient's muscles relaxed, but also enough oxygen to prevent brain and organ damage. This is a difficult task, even with the special training anesthesiologists receive. Amyl nitrite has been used in medicine for over 100 years.
Amyl nitrite comes in ampoules that resemble some types of smelling salts.
When chest pain occurs, the patient breaks open an ampoule and inhales the vapors. Today, doctors prefer to treat angina with tablets containing nitroglycerin, placed under the tongue. Some doctors use it in their offices to test certain functions of the heart. Inhalants are also used in food products and for industrial purposes. Nitrous oxide is used as a sweetening agent in whipped cream.