The international drug epidemic
The injection of medications and the development of intravenous infusions have saved countless lives since these tools of modern medicine were developed. Injection as a route of drug administration provides some obvious advantages to medicine: doses can be measured precisely; the absorptive limitations of the skin, gut, or respiratory mucosa can be bypassed; and agents can be introduced directly into the bloodstream for rapid distribution to target tissues. But these tremendous advantages can be misused and can lead to grave complications. As the epidermal barrier of the immune system is effectively bypassed, unclean needle and syringes can result in direct inoculation of pathogens into the system. As such, risk of bacterial endocarditis in drug users, along with acquisition and transmission of classic blood-borne pathogens, including HIV, HCV, HBV, malaria, tetanus, and syphilis, is exacerbated in IDU. Further, the direct introduction of agents into the bloodstream means rapid intake and distribution of psychoactive agents to the brain-markedly increasing the speed and intensity of the "high," but also increasing the likelihood of overdose and dependence or addiction. The greater efficiency of drug action with injected doses is one of the key drivers of transitions to injection from other less efficient means, like snorting, sniffing, or smoking drugs, and has been reported in multiple settings. As users become addicts and spend down their resources on drugs, the need to get the greatest effect from the drug used drives injection behavior. © 2008 Elsevier Inc. All rights reserved.