Insufflation (medicine)
Insufflation (Latin insufflatio "blowing on or into") is the practice of inhaling substances into a body cavity. Insufflation has limited medical use, but is a common route of administration with many respiratory drugs used to treat conditions in the lungs (asthma or emphysema) and paranasal sinus (allergy).
The technique is common for many recreational drugs and is also used for some entheogens. Nasal insufflation is commonly used for many psychoactive drugs because it causes a much faster onset than orally and bioavailability is usually, but not always, higher than orally. This bioavailability occurs due to the quick absorption of chemical molecules into the bloodstream through the soft tissue in the mucous membrane of the sinus cavity. Some drugs have a higher rate of absorption, and are thus more effective in smaller doses, through this route.
The intranasal route (administration through the nose) may allow certain drugs and other molecules to bypass the blood-brain barrier via diffusion or axonal transport along olfactory and trigeminal nerves.

# Medical uses

## As a medical procedure
Inert, nontoxic gases, such as carbon dioxide, are often insufflated into a body cavity, in order to expand workroom, or reduce obstruction during minimally invasive or laparoscopic surgery.
In the 18th century, the tobacco smoke enema, an insufflation of tobacco smoke into the rectum, was a common method of reviving drowning victims.

## As a method of administering drugs
Insufflation can also be synonymous with inhalation. Psychoactive substances are often inhaled nasally for the purpose of intranasal absorption through the mucous membrane, which is often more rapid, or more complete, than gastrointestinal absorption. For a substance to be effective when insufflated, it must be water soluble so it can be absorbed into the mucous membranes.  This practice is commonly referred to as snorting, bumping, or railing.
Commonly insufflated psychoactive substances include:
- Cocaine - benzoylmethyl ecgonine - a strong stimulant
- Ketamine - dissociative anesthetic
- Heroin/Morphine - powerful opiates
- Opioids - a class of narcotics, typically semi-synthetic (e.g. oxycodone and hydromorphone) or completely synthetic (e.g. meperidine)
- Phencyclidine - dissociative anesthetic, more commonly known by the acronym PCP or slang term angel dust
- Amphetamines - D-methamphetamine (speed) and the racemic D/L-amphetamine
- Ritalin - methylphenidate, a stimulant closely related to amphetamine, but often reported to have effects similar to that of cocaine when insufflated
- MDMA/Ecstasy - an entactogen
- Zolpidem (Ambien) - a sedative hypnotic that can have various hallucinogenic effects with certain people and/or at high doses
- Tobacco snuff - contains nicotine, a mild stimulant that is highly addictive.
- Caffeine - common legal stimulant
Various other drugs can be snorted so long as they are water soluble, though the substances listed are insufflated regularly.
Note: Some psychoactive substances such as benzodiazepines (valium, oxazepam, clonazepam) are water soluble to a small degree (about 350ml/1000 mg). Though this means they will be somewhat effective when insufflated, they will not be as readily absorbed into the mucous membrane as highly soluble substances such as amphetamines and opiates.