Methods of Drug Administration
There are three basic methods for drug administration.
There are three basic methods by which drugs of abuse are taken into the body: by injection, by mouth and via the airways.
Injection
Many drugs are commonly given by intravenous injection including cocaine hydrochloride, heroin, amphetamine and temazepam. The intravenous route affords rapid access to the circulation and thence to the brain, allowing fast onset of intense psychoactive effects. However, bypassing the body’s normal defense mechanisms in the gut carries great risks to health. The subcutaneous route is an alternative which is occasionally used if the intravenous route is not available. Intra-arterial injections are usually only given by mistake when a needle misses a vein. The intramuscular route is only used for anabolic steroids.
Oral Administration
For many drugs the oral route is preferred for convenience – ecstasy, LSD, alcohol and caffeine are all usually taken this way.In addition many of the plants, smart drugs and abused medicines discussed in this blog are administered by mouth. Nearly all drugs can be taken orally; this tends not to be the route of choice because many of them are absorbed from the gut unpredictably, effects can take a long time to develop and/or are blunted. Testosterone, methylphenidate, nitrites and fentanyl are examples of drugs with very poor oral bioavailability.
Administration via airways
There are several methods of exploiting the large surface area for absorption afforded by the human airways. Certain solvents, propellants and fuels can be inhaled directly into the lungs by those engaged in volatile substance abuse. Nitrites are also volatile and can be inhaled directly. Other compounds need to be heated before inhalation is possible. This is called vaporisation. Examples include heroin (’chasing the dragon’), crack cocaine, cannabis resin (’hot knifing’) and metamphetamine. Smoking has a similar net effect but the drug – or drug plus an inflammable vehicle – is set alight first. Tobacco, heroin, phencyclidine and cannabis can be smoked.
Dry powdered drug can be inhaled into the nose, a procedure known as ’snorting’. Amphetamine and cocaine hydrochloride are classically taken by this route.
