This is the 2007 version. Click here for the 2017 chapter 03 table of contents.

Nitrous Oxide and Inhalants

Some dentists use nitrous oxide or "laughing gas" as an anesthetic. (It is not the same as "nitric oxide," the gas which functions as a transmitter, described in Chapter 2.) Mixed with oxygen, nitrous oxide induces a state of altered awareness in which pain is diminished or ignored.

What is nitrous oxide? What is cross-tolerance, and what does it demonstrate?

Its drug action is related to that of opiates. Naloxone, an opiate antagonist (drug which blocks opiates) also eliminates the anesthetic effects of nitrous oxide. Chronic exposure to morphine, which builds up tolerance to opiates, also builds up tolerance to nitrous oxide. This effect is called cross-tolerance : exposure to one drug produces tolerance for another drug. It is evidence for an underlying chemical relationship between drugs.

Why do stolen containers of nitrous oxide sometimes result in deaths?

Overdoses of nitrous oxide can be fatal. One news report told of how containers of nitrous oxide were stolen from a hospital. They turned up at a party where three people died by breathing the concentrated nitrous oxide without oxygen. A container diverted from legitimate medical use contains pure nitrous oxide, intended for mixing with oxygen. Breathing nitrous oxide directly from a tank will smother the user.

Why are inhalants a major drug problem in some populations?

A drug of abuse with effects similar to nitrous oxide is amyl nitrate or "poppers." Once sold in small bottles masquerading as room deodorizers, these drugs are increasingly outlawed due to their abuse potential. They produce a numb, faraway, fainting sensation similar to the feeling of standing up too quickly after being at rest. Amyl nitrate and other inhalants such as glue and paint remover produce an altered state of consciousness primarily by depriving the brain of oxygen.

Many inhalants produce harmful effects over the long term, including permanent brain damage. They are inexpensive and easy to obtain, however, so they are sometimes abused by young teenagers or by very poor people who have no access to more expensive consciousness-altering drugs. In the mid-1990s, for example, Brazil experienced an epidemic of inhalant abuse among impoverished city children who sniffed an inexpensive glue to get high.

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