lean, promethazine, an antiemetic, and unidentified pills. The<unk> —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<unk> s. 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<unk> s, 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<unk> . 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<unk> s 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<unk>  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<unk> <unk>  use, but not all, is intravenous<unk> , whereas some is subcutaneous<unk>  or intramuscular<unk>  (including skin popping, which often involves a depot<unk> .
Drug injection
Disaster medicine
Dental anesthesia
Veterinary anesthesia
Suicide methods
Prescription drug
Oral medicine
Cold medicine