purchase needles without having to feel embarrassed going into a pharmacy. they theorized that with greater access to sterile needles, they would expect to see a reduction in bloodborne pathogen cases. beyond just needle exchange programs, the other major harm reduction strategy for drug users are safe injecting facilities (sifs). these provide a sterile environment for people who inject drugs to do so cleanly, and with sterile syringes which are forced to be thrown away after use so that no re-use occurs. the first of these facilities opened in switzerland, but there are now over 100 globally including one in vancouver - canada, sydney - australia, and most recently, melbourne - australia. modifications particularly for intravenous administration, self-injection in the arm can be awkward, and some people modify a syringe for single-handed operation by removing the plunger and affixing a bulb such as from a large dropper or baby pacifier to the end of the barrel to in effect make it a large dropper with a needle affixed. this is therefore a variant of the common method of injection with a dropper with the hypodermic needle affixed, using a "collar" made of paper or other material to create a seal between the needle and dropper. removing part of the plunger assembly by cutting off most of the shaft and thumb rest and affixing the bulb to the end of the barrel, thereby allowing the bulb to operate the plunger by suction, also does work in many cases. an alternative to syringes in the 1970s was to use a glass medicine dropper, supposedly easier to manipulate with one hand. a large hairpin was used to make a hole in the skin and the dropper containing the drug (usually heroin) was inserted and the bulb squeezed, releasing it into the tissues. this method was also reported—by william s. burroughs and other sources—for intravenous administration at least as far back as 1930. alternatives the closest method to iv/overall injection use, in terms of rapid onset, optimal bioavailability, and reduced health risks for most drugs, tends to be rectal administration via concentrated liquid solution (also known as a suppository), usually consisting of only ~1-3ml of liquid (typically not exceeding 5-10ml) assuming the drug in question possesses sufficient water solubility. while oral morphine has a general bioavailability range is only 20-40%, properly administered rectal use of liquid morphine has an effective bioavailability of roughly 70%, or more than double the overall potency of oral morphine and more than two thirds that of iv use. swallowing tends to be the safest and slowest method of ingesting drugs. it is safer as the body has a much greater chance to filter out impurities. as the drug comes on slower, the effect tends to last longer as well, making it a favorite technique on the dance scene for speed and ecstasy. people rarely take heroin orally, as it is converted to morphine in the stomach and its potency is reduced by more than 65% in the process. however, oral bioavailability of opioids is heavily dependent on the substance, dose, and patient in ways that are not yet understood. history iv drug use is a relatively recent phenomenon arising from the invention of re-usable syringes and the synthesis of chemically pure morphine and cocaine. it was noted that administering drugs intravenously strengthened their effect, and—since such drugs as heroin and cocaine were already being used to treat a wide variety of ailments—many patients were given injections of "hard" drugs for such ailments as alcoholism and depression. origin and early use the hypodermic needle and syringe in its current form was invented by the french scientist charles pravaz in 1851, and became especially known during the wars of that and the subsequent decade. however, the first well-known attempt to inject drugs into the body was a 1667 attempt to inject a solution of opium into a dog, and some had suspected that parenteral administration of drugs may work better based on the practise of rubbing opium and other drugs into sores or cuts on the skin for the purpose of causing systemic absorption and the beginnings of scientific understanding of the functioning of the lungs. during most of the 1850s, the previously held belief that opiate dependence and addiction (often called "the opium appetite", or, when relevant, the "morphine appetite" or "codeine appetite") was due to the drug's action on the digestive system—just like any hunger or thirst—caused doctors to opt to inject morphine rather than administer it orally, in the hope that addiction would not develop. certainly, by c. 1870 or earlier, it was manifest that this was not the case and the title of earliest morphine addict as the term is currently understood is often given to pravaz' wife, although habituation through orally ingesting the drug was known before this time, including friedrich sertürner and his associates, followers, wife, and dog. to some extent, it was also believed early on that bypassing the lungs would prevent opium addiction, as well as habituation to tobacco. ethanol in its usual form generally is not injected and can be very damaging by most routes of injection; in modern times, it is used as an alternative or potentiator of phenol (carbolic acid) in procedures to ablate damaged nerves. in or shortly after 1851, the drugs which had been discovered and extracted from their plants of origin and refined into pure crystalline salts soluble in water included morphine (1804 or late 1803), codeine (1832), narcotine/noscapine (1803–1805?), papaverine (1814), cocaine (1855), caffeine (1819), quinine (1820), atropine (1831), scopolamine (aka hyoscine, aka laevo-duboisine) (1833?), hyoscyamine or laevo-atropine (1831), opium salts mixtures (c. 1840s), chloral derivatives (1831 et seq.), ephedrine (1836?), nicotine (1828), and many others of all types, psychoactive and not. morphine in particular was used much more widely after the invention of the hypodermic syringe, and the practise of local anaesthesia by infiltration was another step forward in medicine resulting from the hypodermic needle, discovered at around the same time that it was determined that cocaine produced useful numbing of the mucous membranes and eye. 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, and even liquids and suppositories—are also occasionally injected. this applies particularly to prescription opioids, since some opioid addicts already inject heroin. injecting preparations which were 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, and other codeine-based products carry similar risks. codeine may instead be injected by the intramuscular or subcutaneous route. the effect will not be instant, but the dangerous and unpleasant massive histamine release from the intravenous injection of codeine is avoided. to minimize the amount of undissolved material in fluids prepared for injection, a filter of cotton or synthetic fiber is typically used, such as a cotton-swab tip or a small piece of cigarette filter. 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.