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Insufflation (Latin insufflatio "blowing on" or "into") is the act of blowing something (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 paediatric patients 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. This practice is commonly referred to as snorting, bumping, railing, or doozing.
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. This effect is commonly referred to as the 'drip' and is often unpleasant to taste.
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.
Nasal inphalangalation is a moderated technique of intranasal vascular absorption, widely believed to have beneficial use as a recreational route of administration; it is intended exclusively for the intake of psychoactive drugs in chloride form. The chloride crystals are pasted onto a moist fingertip, and then inserted into either nostril. A sharp breath and quick rotation of the fingertip ensure the powder's transfer from the digit into the inner nostril and sinus. Though lacking in popular appeal, nasal inphalangalation assists primarily in the minimization of the typically painful intranasal vascular absorption of the chloride. The robust inner nostril ingests the salt without registering the usual intense burn of standard insufflation, allowing for prolonged periods of consistent nasal inphalangalation. The method also eliminates the introduction of unabsorbed salt crystals to the tonsils and gastrointestinal tract, thereby preventing corrosive tonsilar erosion and potentially unpleasant gastric reactions. However, given the corrosive nature of chloride, chronic nasal inphalangalation can facilitate nasal septal dissolution, as well as the erosion of the remaining inner nostril. The bioavailability and immediate euphoric neurological reaction of nasal inphalangalation mirror that of standard insufflation, suggesting that despite the increased comfort, nasal inphalangalation shares standard insufflation's absence of appropriate medical application; therefore, classification incorporates nasal inphalangalation as a recreational route of administration.
- William H. Frey. "Bypassing the Blood-Brain Barrier to Deliver Therapeutic Agents to the Brain and Spinal Cord." Drug Delivery Technology.
- Lawrence, Ghislaine (20 April 2002). "Tobacco smoke enemas". The Lancet 359 (9315): 1442. http://www.thelancet.com/journals/lancet/article/PIIS0140-6736(02)08339-3/fulltext. Retrieved 2008-11-27.
- Definition of dooze, definition No.4 
- Born J, Lange T, Kern W, McGregor GP, Bickel U, Fehm HL. (2002). Sniffing neuropeptides: a transnasal approach to the human brain. Nat Neurosci.5(6):514-6. doi:10.1038/nn849 PMID 11992114
- Aaron S, McMahon JM, Milano D, Torres L, Clatts M, Tortu S, Mildvan D, Simm M. (2008). "Intranasal Transmission of Hepatitis C Virus: Virological and Clinical Evidence". Clinical Infectious Diseases 47 (7): 931–934. doi:10.1086/591699.