drug injection drug injection drug injection is a method of introducing a drug into the bloodstream via a hollow hypodermic needle, which is pierced through the skin into the body (usually intravenously, but also at an intramuscular or subcutaneous location). intravenous therapy, a form of drug injection, is universally practiced in modernized medical care. as of 2004, there were 13.2 million people worldwide who self-administered injection drugs outside of medical supervision, of which 22% are from developed countries. this article describes drug injections primarily in the context of recreational drug use. for a focus on medical practices, see intravenous therapy, or intramuscular injection. fragment of a hypodermic needle stuck inside the arm of an iv drug user (x-ray) a wide variety of drugs are injected, often opioids: these may include legally prescribed medicines and medication such as morphine, as well as stronger compounds often favored in recreational drug use, which are often illegal. although there are various methods of taking drugs, injection is favoured by some people as the full effects of the drug are experienced very quickly, typically in five to ten seconds. it also bypasses first-pass metabolism in the liver, resulting in higher bioavailability and efficiency for many drugs (such as morphine or diacetylmorphine/heroin; roughly two-thirds of which is destroyed in the liver when consumed orally) than oral ingestion would. the effect is that the person gets a stronger (yet shorter-acting) effect from the same amount of the drug. drug injection is therefore often related to substance dependence. in recreational-use drug culture, preparation may include mixing the powdered drug with water to create an aqueous solution, and then the solution is injected. this act is often colloquially referred to as "slamming", "shooting up", "smashing", "banging", "pinning", or "jacking-up", often depending on the specific drug subculture in which the term is used (i.e. heroin, cocaine, or methamphetamine). risks in addition to general problems associated with any iv drug administration (see risks of iv therapy), there are some specific problems associated with the injection of drugs by non-professionals, such as: chance of infection – this is generally a twofold major concern: needle sharing or sharing syringes may transmit blood-borne diseases between users, such as hiv-aids and hepatitis c abscessed infections of injection sites are caused by lack of proper hygiene and a lack of aseptic technique during the injection process. increased chance of overdose – because iv injection delivers a dose of drug straight into the bloodstream, it is harder to gauge how much to use (as opposed to smoking or snorting, where the dose can be increased relatively incrementally until the desired effect is achieved; this gives a user who is in danger of overdosing a chance to seek medical treatment before respiratory arrest sets in). in addition, because of the rapid onset of intravenous drugs, overdose can occur very quickly, requiring immediate action. another reason that overdose is a risk is because the purity of street drugs varies a great deal. scarring of the peripheral veins – this arises from the use of blunt injecting equipment. this is particularly common with users who have been injecting while in jail and re-use disposable syringes sometimes hundreds of times. iv drug use for an extended period may result in collapsed veins. though rotating sites and allowing time to heal before reuse may decrease the likelihood of this occurring, collapse of peripheral veins may still occur with prolonged iv drug use. iv drug users are among the most difficult patient populations to obtain blood-specimens from because of peripheral venous scarring. the darkening of the veins due to scarring and toxin buildup produce tracks along the length of the veins and are known as track marks. arterial damage – arterial pseudoaneurysms may form at injection sites, which can rupture, potentially resulting in hemorrhage, distal ischemia, and gangrene. inadvertent intra-arterial injection can also result in endarteritis and thrombosis, with ultimately similar consequences. increased chance of addiction – the heightened effect of administering drugs intravenously can make the chances of addiction more likely. social stigma – in many societies, there is a social stigma attached to iv drug use, in addition to the more general stigma around illegal drug use and addiction. methods a clandestine kit containing materials to inject drugs, a bottle of a type of lean, promethazine, an antiemetic, and unidentified pills the drug—usually (but not always) in a powder or crystal form—is dissolved in water, normally in a spoon, tin, bottle cap, the bottom of a soda can, or another metal container. cylindrical metal containers—sometimes called "cookers"—are provided by needle exchange programs. users draw the required amount of water into a syringe and squirt this over the drugs. the solution is then mixed and heated from below if necessary. heating is used mainly with heroin (though not always, depending on the type of heroin), but is also often used with other drugs, especially crushed tablets. cocaine hcl (powdered cocaine) dissolves quite easily without heat. heroin prepared for the european market is insoluble in water and usually requires the addition of an acid such as citric acid or ascorbic acid (vitamin c) powder to dissolve the drug. due to the dangers from using lemon juice or vinegar to acidify the solution, packets of citric acid and vitamin c powder are available at needle exchanges in europe. in the u.s., vinegar and lemon juice are used to shoot crack cocaine. the acids convert the water-insoluble cocaine base in crack to a cocaine salt (cocaine acetate or cocaine citrate), which is water-soluble (like cocaine hydrochloride). once the drugs are dissolved, a small syringe (usually 0.5 or 1 cc) is used to draw the solution through a filter, usually cotton from a cigarette filter or cotton swab (cotton bud). "tuberculin" syringes and types of syringes used to inject insulin are commonly used. commonly used syringes usually have a built-in 28 gauge (or thereabouts) needle typically 1/2 or 5/8 inches long. the preferred injection site is the crook of the elbow (i.e., the median cubital vein), on the user's non-writing hand. other users opt to use the basilic vein; while it may be easier to "hit", caution must be exercised as two nerves run parallel to the vein, increasing the chance of nerve damage, as well as the chance of an arterial "nick". regarding route of administration, much injection drug use, but not all, is intravenous injection, whereas some is subcutaneous injection or intramuscular injection (including skin popping, which often involves a depot injection). recreational drugs risks risks from drug injection are caused by a variety of factors, including unclean or unsafe injection practices such as blood flashing and repeated injections at the same site. injection drug users that fail to adequately sanitize the skin or use clean injection products are at increased risk for cellulitis, abscesses, and thrombophlebitis; these infections can subsequently result in sepsis and bacteremia, which can be fatal if untreated. repetitive injections, especially those with unsafe practices, can result in additional medical concerns that include thrombosis formation and infectious endocarditis. in rare cases osteomyelitis of the chest can be caused by iv drug use. additional risks from unsafe injection practices result primarily from sharing materials (needles, cookers, syringes) used in injection. blood-borne pathogens, such as hiv, hepatitis b, and hepatitis c are of particular concern among injection drug users who share supplies, and increase the likelihood of infection. an added challenge, is that not only infected individuals know their positive status and continue to share supplies, placing other users at risk for infection as well. 30-50% of adults will not experience acute hepatitis b symptoms, and those that do experience lethargy, nausea, upper abdominal pain, muscle aches, or a darkening of urine will need to connect these symptoms to a possible infection to seek care and limit spreading of the virus. of all the ways to ingest drugs, injection carries the most risks by far as it bypasses the body's natural filtering mechanisms against viruses, bacteria, and foreign objects. there will always be much less risk of overdose, disease, infections, and health problems with alternatives to injecting, such as smoking, insufflation (snorting or nasal ingestion), or swallowing. drug injection is also commonly a component in hiv-related syndemics. fragments from injection of pills are known to clog the small blood vessels of the lungs, brain, and elsewhere, potentially causing pulmonary embolism (pe), stroke, or venous embolism. a small proportion of pe is due to the embolization of air, fat, and talc in the drugs of people who inject substances. more commonly, the inflammatory response to these foreign objects causes granulation tissue to form in the capillary beds, resulting in vasculitis, and, when it occurs in the pulmonary capillary bed, potentially pulmonary talcosis. hitting arteries and nerves is dangerous, painful, and presents its own similar spectrum of problems. the injection of talc from crushed pills has been associated with pulmonary talcosis in intravenous drug users. harm reduction a sterile and safe injection kit obtained from a needle exchange program harm reduction is a public health approach that serves as an alternative to abstinence-only guidance. while it does not condone the use of illicit or illegal drugs, it does seek to reduce the harms, risks and dangers associated with illicit drug use, both for the person using illicit drugs and the wider community. injection drug users that re-use drug delivery components put themselves and others at risk for diseases such as hiv, hepatitis b, and hepatitis c, as well as increase their chances of getting a serious infection. in 2015, the cdc performed an hiv surveillance report and attributed 2,392 (6%) of new hiv diagnoses to iv drug use in the us. a prominent method for addressing the issue of disease transmission among intravenous drug users are needle exchange programs (also known as syringe exchange programs, syringe service programs or needle-syringe programs), where people who inject drugs (pwid) can access sterile needles, syringes, and other paraphernalia. in addition to providing sterile devices used in drug injection, these programs often offer access to infectious disease testing, referrals for substance use or mental health treatment programs, and more. the idea behind harm reduction approaches is to slow disease transmission, such as hiv/aids and hepatitis b and c, and promote public health by reducing the practice of sharing used needles. in countries where harm reduction programs are limited or non-existent, it is quite common for an iv users to use a single needle repeatedly or share with other users. it is also quite uncommon for a sterilizing agent to be used on needles and syringes. this creates a high risk population for the spread of bloodborne pathogens. a new approach to reduce harm to iv drug users was recently started in southern nevada in 2017. trac-b exchange - southern nevada harm reduction program was approved in early 2017 to help reduce the spread of hiv in "people who inject drugs". in nevada, the sharing of needles for drug injections has led to an increase in the spread of hiv and hepatitis b and c. in an effort to reduce the spread of blood borne pathogens, southern nevada installed vending machines to give access to sterile needles to those using them for drug injections. individuals who use these vending machines are required to register with trac-b and are allowed 2 boxes a week. the boxes contain sterile needles as well as other supplies necessary to reduce the risk of spreading blood borne pathogens. if this pilot program is successful in reducing the spread of bloodborne pathogens, we may see programs like this spread to other parts of the country. although this is a new idea in the united states, it was tested in europe over 20 years ago. in order to combat the aids epidemic that was spreading across europe, france allowed pharmacies to dispense needles without a prescription and implemented needle exchange programs. in 1996, they began a pilot program of syringe vending machines, similar to a coin-operated vending machine. the first vending machines were placed in marseille due to its high occurrence of aids caused by sharing of needles. the results of their study was published in 1999. they found that when the availability of syringes increased, more and more people began to purchase sterile needles. it also provided a discreet way for people to