Insufflation (Latin
insufflatio "blowing on" or "into") is the practice of
inhaling a substance. 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).