Drug injection

Injection of recreational drugs is a method of introducing the drug into the body with a hollow needle and a syringe which is pierced through the skin into the body (usually intravenous, but also intramuscular or subcutaneous). This act is often colloquially referred to as shooting or banging. Although there are various methods of taking drugs, injection is favoured by some users 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 a higher bioavailability for many drugs than oral ingestion would (so users get a stronger effect from the same amount of the drug). This shorter, more intense high can lead to a dependency, both physical and psychological, developing more quickly than with other methods of taking drugs.

While a wide variety of drugs are injected, among the most popular in many countries are morphine, heroin, cocaine, amphetamine and methamphetamine. Prescription drugs, including tablets, capsules, or even liquids or suppositories, are also sometimes injected, especially prescription opioids, since many opioid addicts already inject heroin. Injecting preparations not intended for this purpose is particularly dangerous because of the presence of excipients (fillers), which can cause blood clots. Injecting codeine into the bloodstream directly is dangerous because it causes a rapid histamine release, which can lead to potentially fatal anaphylaxis and pulmonary edema. Dihydrocodeine, hydrocodone, nicocodeine, thebaine and other codeine-based products also carry a moderate risk in this case.[citation needed]

Some manufacturers add the narcotic antagonist naloxone or the anticholinergics atropine and homatropine (in lower than therapeutic doses) to their pills to prevent injection. Unlike naloxone, atropine does indeed help morphine and other narcotics combat neuralgia. The atropine may very well not present a problem, and there is the possibility of atropine content reduction of soluble tablets by placing them on an ink blotter with a drop of water on top, then preparing a shot from the remainder of the pill. Canada and many other countries prohibit manufacturers from including secondary active ingredients for the above reason; their Talwin PX does not contain naloxone. However, as a narcotic agonist-antagonist, pentazocine and its relatives can cause withdrawal in those physically dependent upon narcotics.