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Insufflation (Latin insufflation "blowing on" or "into") is the act of inhaling something (such as a gas, powder, or vapor) into a body cavity. Insufflation has medical use as a route of administration for many respiratory drugs used to treat conditions in the lungs (e.g., asthma or emphysema) and paranasal sinus (e.g., allergy).
The technique is common for many recreational drugs and is also used for some entheogens. Nasal insufflation (snorting) 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 molecules into the bloodstream through the soft tissue in the mucous membrane of the sinus cavity and portal circulation bypass. Some drugs have a higher rate of absorption, and are thus more effective in smaller doses, through this route. Prodrugs, drugs that are metabolized or activated by the liver (such as codeine), should not be insufflated, because they need to be metabolized by the liver to break down into the compounds that are active (drugs absorbed through the GI tract pass through the liver before entering the systemic circulation, where drugs which are insufflated are absorbed directly into the systemic circulation).
The intranasal route (administration through the nose) may allow certain drugs and other molecules to bypass the blood–brain barrier via diffusion through the olfactory epithelium and the perineural sheath or via retrograde axonal transport along olfactory and trigeminal nerves. This latter process probably implies endocytosis of the molecules. Using this route to the brain allows high concentrations of products in the olfactory bulb shortly after exposition and by diffusion to the entire brain. Therefore using this pathway allows a better bioavailability, assuming that the molecule has the right physico-chemical characteristics to get through the nose and the epithelial defences.
Intranasal (IN) administration of various lipid-soluble medications is increasing in popularity. It is often used for treatment of children or patients who are otherwise alarmed or frightened by needles, or where intravenous (IV) access is unavailable. In addition to a variety of nasal sprays readily available from pharmacies, some common medications delivered via IN include fentanyl, midazolam and naloxone. The time of onset for drugs delivered intranasally is generally only marginally slower than if given via IV.
Psychoactive substances are often insufflated 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. The verb "snort" is synonymous with insufflate in this context, as are several slang words.
Although the majority of a dose of insufflated drug is taken up through the mucous membranes, some enters other parts of the gastrointestinal tract where it may also be absorbed. This is because some of the dose drips down the throat and into the stomach.
Commonly insufflated psychoactive substances (for non-medical use) include:
- Cocaine (benzoylmethylecgonine) - a strong stimulant that is highly addictive; most commonly associated with drug insufflation
- Opioids - a class of analgesic drugs (including heroin, morphine, oxycodone, buprenorphine, hydromorphone, oxymorphone and the synthetic meperidine and fentanyl).
- Amphetamines - another class of strong stimulants (including amphetamine, dextroamphetamine and methamphetamine) that are also highly addictive.
- Ritalin (methylphenidate) - another stimulant somewhat pharmacologically similar to cocaine; sometimes claimed to have effects similar to that of cocaine when insufflated
- Ketamine - a dissociative anaesthetic, used recreationally for its euphoric, anaesthetic and hallucinatory effects
- Phencyclidine - a dissociative anaesthetic, commonly known as PCP or angel dust; no longer in common use because of reports of intensely negative experiences
- MDMA/Ecstasy - an entactogen that also possesses stimulant effects
- 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.
Many recreational drugs which are commonly insufflated such as cocaine, can cause damage to the nasal cavity and have even been known to destroy the nasal septum. Any damage to the inside of the nose is either because some insufflation highly constricts blood vessels – and therefore blood and oxygen/nutrient flow – to that area, or because the substance is physically corrosive. A famous case where the septum was completely destroyed by cocaine was of EastEnders star Danniella Westbrook.
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