Cocaine (Drugs / Substance Abuse)

Cocaine (INN) (benzoylmethylecgonine, an ecgonine derivative) is a crystalline tropane alkaloid that is obtained from the leaves of the coca plant. The name comes from “coca” and the alkaloid suffix “-ine”, forming “cocaine”. It is a stimulant, an appetite suppressant, and a topical anesthetic. Biologically, cocaine acts as a serotonin–norepinephrine–dopamine reuptake inhibitor, also known as a triple reuptake inhibitor (TRI). It is addictive because of its effect on the mesolimbic reward pathway.Unlike most molecules, cocaine has pockets[clarification needed] with both high hydrophilic and lipophilic efficiency, violating the rule of hydrophilic-lipophilic balance. This causes it to cross the blood–brain barrier far better than other psychoactive chemicals[citation needed] and may even induce blood-brain barrier breakdown.It is controlled internationally by Single Convention on Narcotic Drugs (Schedule I, preparation in Schedule III).

cocaine

Medical Effects
Cocaine is a powerful nervous system stimulant. Its effects can last from 15–30 minutes to an hour, depending on dosage and the route of administration.

Cocaine increases alertness, feelings of well-being and euphoria, energy and motor activity, feelings of competence and sexuality. Athletic performance may be enhanced in sports where sustained attention and endurance is required. Anxiety, paranoia and restlessness can also occur, especially during the comedown. With excessive dosage, tremors, convulsions and increased body temperature are observed.

Occasional cocaine use does not typically lead to severe or even minor physical or social problems.

Acute
With excessive or prolonged use, the drug can cause itching, tachycardia, hallucinations, and paranoid delusions. Overdoses cause hyperthermia and a marked elevation of blood pressure, which can be life-threatening.

Chronic
Chronic cocaine intake causes brain cells to adapt functionally to strong imbalances of transmitter levels in order to compensate extremes. Thus, receptors disappear from the cell surface or reappear on it, resulting more or less in an “off” or “working mode” respectively, or they change their susceptibility for binding partners (ligands) – mechanisms called down-/upregulation. However, studies suggest cocaine abusers do not show normal age-related loss of striatal dopamine transporter (DAT) sites, suggesting cocaine has neuroprotective properties for dopamine neurons. The experience of insatiable hunger, aches, insomnia/oversleeping, lethargy, and persistent runny nose are often described as very unpleasant. Depression with suicidal ideation may develop in very heavy users. Finally, a loss of vesicular monoamine transporters, neurofilament proteins, and other morphological changes appear to indicate a long term damage of dopamine neurons. All these effects contribute a rise in tolerance thus requiring a larger dosage to achieve the same effect.

The lack of normal amounts of serotonin and dopamine in the brain is the cause of the dysphoria and depression felt after the initial high. Physical withdrawal is not dangerous. Physiological changes caused by cocaine withdrawal include vivid and unpleasant dreams, insomnia or hypersomnia, increased appetite and psychomotor retardation or agitation.

Physical side effects from chronic smoking of cocaine include hemoptysis, bronchospasm, pruritus, fever, diffuse alveolar infiltrates without effusions, pulmonary and systemic eosinophilia, chest pain, lung trauma, sore throat, asthma, hoarse voice, dyspnea (shortness of breath), and an aching, flu-like syndrome. Cocaine constricts blood vessels, dilates pupils, and increases body temperature, heart rate, and blood pressure. It can also cause headaches and gastrointestinal complications such as abdominal pain and nausea. A common but untrue belief is that the smoking of cocaine chemically breaks down tooth enamel and causes tooth decay. However, cocaine does often cause involuntary tooth grinding, known as bruxism, which can deteriorate tooth enamel and lead to gingivitis. Additionally, stimulants like cocaine, methamphetamine, and even caffeine cause dehydration and dry mouth. Since saliva is an important mechanism in maintaining one’s oral pH level, chronic stimulant abusers who do not hydrate sufficiently may experience demineralization of their teeth due to the pH of the tooth surface dropping too low (below 5.5).

Chronic intranasal usage can degrade the cartilage separating the nostrils (the septum nasi), leading eventually to its complete disappearance. Due to the absorption of the cocaine from cocaine hydrochloride, the remaining hydrochloride forms a dilute hydrochloric acid.

Cocaine may also greatly increase this risk of developing rare autoimmune or connective tissue diseases such as lupus, Goodpasture’s disease, vasculitis, glomerulonephritis, Stevens–Johnson syndrome and other diseases. It can also cause a wide array of kidney diseases and renal failure.

Cocaine misuse doubles both the risks of hemorrhagic and ischemic strokes, as well as increases the risk of other infarctions, such as myocardial infarction.

Addiction
Cocaine dependence (or addiction) is psychological dependency on the regular use of cocaine. Cocaine dependency may result in physiological damage, lethargy, psychosis, depression, akathisia, and fatal overdose.

Biosynthesis
The first synthesis and elucidation of the cocaine molecule was by Richard Willstätter in 1898. Willstätter’s synthesis derived cocaine from tropinone. Since then, Robert Robinson and Edward Leete have made significant contributions to the mechanism of the synthesis. (-NO3)

The additional carbon atoms required for the synthesis of cocaine are derived from acetyl-CoA, by addition of two acetyl-CoA units to the N-methyl-Δ1-pyrrolinium cation. The first addition is a Mannich-like reaction with the enolate anion from acetyl-CoA acting as a nucleophile towards the pyrrolinium cation. The second addition occurs through a Claisen condensation. This produces a racemic mixture of the 2-substituted pyrrolidine, with the retention of the thioester from the Claisen condensation. In formation of tropinone from racemic ethyl [2,3-13C2]4(Nmethyl-2-pyrrolidinyl)-3-oxobutanoate there is no preference for either stereoisomer. In the biosynthesis of cocaine, however, only the (S)-enantiomer can cyclize to form the tropane ring system of cocaine. The stereoselectivity of this reaction was further investigated through study of prochiral methylene hydrogen discrimination. This is due to the extra chiral center at C-2. This process occurs through an oxidation, which regenerates the pyrrolinium cation and formation of an enolate anion, and an intramolecular Mannich reaction. The tropane ring system undergoes hydrolysis, SAM-dependent methylation, and reduction via NADPH for the formation of methylecgonine. The benzoyl moiety required for the formation of the cocaine diester is synthesized from phenylalanine via cinnamic acid. Benzoyl-CoA then combines the two units to form cocaine.

N-methyl-pyrrolinium cation
The biosynthesis begins with L-Glutamine, which is derived to L-ornithine in plants. The major contribution of L-ornithine and L-arginine as a precursor to the tropane ring was confirmed by Edward Leete. Ornithine then undergoes a Pyridoxal phosphate-dependent decarboxylation to form putrescine. In animals, however, the urea cycle derives putrescine from ornithine. L-ornithine is converted to L-arginine, which is then decarboxylated via PLP to form agmatine. Hydrolysis of the imine derives N-carbamoylputrescine followed with hydrolysis of the urea to form putrescine. The separate pathways of converting ornithine to putrescine in plants and animals have converged. A SAM-dependent N-methylation of putrescine gives the N-methylputrescine product, which then undergoes oxidative deamination by the action of diamine oxidase to yield the aminoaldehyde. Schiff base formation confirms the biosynthesis of the N-methyl-Δ1-pyrrolinium cation.

Robert Robinson’s acetonedicarboxylate
The biosynthesis of the tropane alkaloid, however, is still uncertain. Hemscheidt proposes that Robinson’s acetonedicarboxylate emerges as a potential intermediate for this reaction. Condensation of N-methylpyrrolinium and acetonedicarboxylate would generate the oxobutyrate. Decarboxylation leads to tropane alkaloid formation.

Reduction of tropinone
The reduction of tropinone is mediated by NADPH-dependent reductase enzymes, which have been characterized in multiple plant species. These plant species all contain two types of the reductase enzymes, tropinone reductase I and tropinone reductase II. TRI produces tropine and TRII produces pseudotropine. Due to differing kinetic and pH/activity characteristics of the enzymes and by the 25-fold higher activity of TRI over TRII, the majority of the tropinone reduction is from TRI to form tropine.

cocaine2

Pharmacology

Appearance
Cocaine in its purest form is a white, pearly product. Cocaine appearing in powder form is a salt, typically cocaine hydrochloride (CAS 53-21-4). Street market cocaine is frequently adulterated or “cut” with various powdery fillers to increase its weight; the substances most commonly used in this process are baking soda; sugars, such as lactose, dextrose, inositol, and mannitol; and local anesthetics, such as lidocaine or benzocaine, which mimic or add to cocaine’s numbing effect on mucous membranes. Cocaine may also be “cut” with other stimulants such as methamphetamine. Adulterated cocaine is often a white, off-white or pinkish powder.

The color of “crack” cocaine depends upon several factors including the origin of the cocaine used, the method of preparation – with ammonia or baking soda – and the presence of impurities, but will generally range from white to a yellowish cream to a light brown. Its texture will also depend on the adulterants, origin and processing of the powdered cocaine, and the method of converting the base. It ranges from a crumbly texture, sometimes extremely oily, to a hard, almost crystalline nature.

Forms

Salts
Cocaine is a weakly alkaline compound (an “alkaloid”), and can therefore combine with acidic compounds to form various salts. The hydrochloride (HCl) salt of cocaine is by far the most commonly encountered, although the sulfate (-SO4) and the nitrate (-NO3) are occasionally seen. Different salts dissolve to a greater or lesser extent in various solvents – the hydrochloride salt is polar in character and is quite soluble in water.

Basic
As the name implies, “freebase” is the base form of cocaine, as opposed to the salt form. It is practically insoluble in water whereas hydrochloride salt is water soluble.

Smoking freebase cocaine has the additional effect of releasing methylecgonidine into the user’s system due to the pyrolysis of the substance (a side effect which insufflating or injecting powder cocaine does not create). Some research suggests that smoking freebase cocaine can be even more cardiotoxic than other routes of administration because of methylecgonidine’s effects on lung tissue and liver tissue.

Pure cocaine is prepared by neutralizing its compounding salt with an alkaline solution which will precipitate to non-polar basic cocaine. It is further refined through aqueous-solvent Liquid-liquid extraction.

cocaine3

Crack cocaine
Crack is a lower purity form of free-base cocaine that is usually produced by neutralization of cocaine hydrochloride with a solution of baking soda (sodium bicarbonate, NaHCO3) and water, producing a very hard/brittle, off-white-to-brown colored, amorphous material that contains sodium carbonate, entrapped water, and other by-products as the main impurities.

The “freebase” and “crack” forms of cocaine are usually administered by vaporization of the powdered substance into smoke, which is then inhaled. The origin of the name “crack” comes from the “crackling” sound (and hence the onomatopoeic moniker “crack”) that is produced when the cocaine and its impurities (i.e. water, sodium bicarbonate) are heated past the point of vaporization. Pure cocaine base/crack can be smoked because it vaporizes smoothly, with little or no decomposition at 98 °C (208 °F), which is below the boiling point of water. The smoke produced from cocaine base is usually described as having a very distinctive, pleasant taste.

In contrast, cocaine hydrochloride does not vaporize until heated to a much higher temperature (about 197°C), and considerable decomposition/burning occurs at these high temperatures. This effectively destroys some of the cocaine, and yields a sharp, acrid, and foul-tasting smoke.

Smoking or vaporizing cocaine and inhaling it into the lungs produces an almost immediate “high” that can be very powerful (and addicting) quite rapidly – this initial crescendo of stimulation is known as a “rush”. While the stimulating effects may last for hours, the euphoric sensation is very brief, prompting the user to smoke more immediately.

Coca leaf infusions
Coca herbal infusion (also referred to as Coca tea) is used in coca-leaf producing countries much as any herbal medicinal infusion would elsewhere in the world. The free and legal commercialization of dried coca leaves under the form of filtration bags to be used as “coca tea” has been actively promoted by the governments of Peru and Bolivia for many years as a drink having medicinal powers. Visitors to the city of Cuzco in Peru, and La Paz in Bolivia are greeted with the offering of coca leaf infusions (prepared in tea pots with whole coca leaves) purportedly to help the newly arrived traveler overcome the malaise of high altitude sickness. The effects of drinking coca tea are a mild stimulation and mood lift. It does not produce any significant numbing of the mouth nor does it give a rush like snorting cocaine. In order to prevent the demonization of this product, its promoters publicize the unproven concept that much of the effect of the ingestion of coca leaf infusion would come from the secondary alkaloids, as being not only quantitatively different from pure cocaine but also qualitatively different.

It has been promoted as an adjuvant for the treatment of cocaine dependence. In one controversial study, coca leaf infusion was used -in addition to counseling- to treat 23 addicted coca-paste smokers in Lima, Peru. Relapses fell from an average of four times per month before treatment with coca tea to one during the treatment. The duration of abstinence increased from an average of 32 days prior to treatment to 217 days during treatment. These results suggest that the administration of coca leaf infusion plus counseling would be an effective method for preventing relapse during treatment for cocaine addiction. Importantly, these results also suggest strongly that the primary pharmacologically active metabolite in coca leaf infusions is actually cocaine and not the secondary alkaloids.
The cocaine metabolite benzoylecgonine can be detected in the urine of people a few hours after drinking one cup of coca leaf infusion.

Routes of administration

Oral
Many users rub the powder along the gum line, or onto a cigarette filter which is then smoked, which numbs the gums and teeth – hence the colloquial names of “numbies”, “gummers” or “cocoa puffs” for this type of administration. This is mostly done with the small amounts of cocaine remaining on a surface after insufflation. Another oral method is to wrap up some cocaine in rolling paper and swallow (parachute) it. This is sometimes called a “snow bomb.”

Coca leaf
Coca leaves are typically mixed with an alkaline substance (such as lime) and chewed into a wad that is retained in the mouth between gum and cheek (much in the same as chewing tobacco is chewed) and sucked of its juices. The juices are absorbed slowly by the mucous membrane of the inner cheek and by the gastrointestinal tract when swallowed. Alternatively, coca leaves can be infused in liquid and consumed like tea. Ingesting coca leaves generally is an inefficient means of administering cocaine. Advocates of the consumption of the coca leaf state that coca leaf consumption should not be criminalized as it is not actual cocaine, and consequently it is not properly the illicit drug. Because cocaine is hydrolyzed and rendered inactive in the acidic stomach, it is not readily absorbed when ingested alone. Only when mixed with a highly alkaline substance (such as lime) can it be absorbed into the bloodstream through the stomach. The efficiency of absorption of orally administered cocaine is limited by two additional factors. First, the drug is partly catabolized by the liver. Second, capillaries in the mouth and esophagus constrict after contact with the drug, reducing the surface area over which the drug can be absorbed. Nevertheless, cocaine metabolites can be detected in the urine of subjects that have sipped even one cup of coca leaf infusion. Therefore, this is an actual additional form of administration of cocaine, albeit an inefficient one.

Orally administered cocaine takes approximately 30 minutes to enter the bloodstream. Typically, only a third of an oral dose is absorbed, although absorption has been shown to reach 60% in controlled settings. Given the slow rate of absorption, maximum physiological and psychotropic effects are attained approximately 60 minutes after cocaine is administered by ingestion. While the onset of these effects is slow, the effects are sustained for approximately 60 minutes after their peak is attained.

Contrary to popular belief, both ingestion and insufflation result in approximately the same proportion of the drug being absorbed: 30 to 60%. Compared to ingestion, the faster absorption of insufflated cocaine results in quicker attainment of maximum drug effects. Snorting cocaine produces maximum physiological effects within 40 minutes and maximum psychotropic effects within 20 minutes, however, a more realistic activation period is closer to 5 to 10 minutes, which is similar to ingestion of cocaine. Physiological and psychotropic effects from nasally insufflated cocaine are sustained for approximately 40–60 minutes after the peak effects are attained.

Coca tea, an infusion of coca leaves, is also a traditional method of consumption. The tea has often been recommended for travelers in the Andes to prevent altitude sickness. However, its actual effectiveness has never been systematically studied. This method of consumption has been practiced for many centuries by the native tribes of South America. One specific purpose of ancient coca leaf consumption was to increase energy and reduce fatigue in messengers who made multi-day quests to other settlements.

In 1986 an article in the Journal of the American Medical Association revealed that U.S. health food stores were selling dried coca leaves to be prepared as an infusion as “Health Inca Tea.” While the packaging claimed it had been “decocainized,” no such process had actually taken place. The article stated that drinking two cups of the tea per day gave a mild stimulation, increased heart rate, and mood elevation, and the tea was essentially harmless. Despite this, the DEA seized several shipments in Hawaii, Chicago, Illinois, Georgia, and several locations on the East Coast of the United States, and the product was removed from the shelves.

Insufflation
Nasal insufflation (known colloquially as “snorting,” “sniffing,” or “blowing”) is the most common method of ingestion of recreational powdered cocaine in the Western world. The drug coats and is absorbed through the mucous membranes lining the sinuses. When insufflating cocaine, absorption through the nasal membranes is approximately 30–60%, with higher doses leading to increased absorption efficiency. Any material not directly absorbed through the mucous membranes is collected in mucus and swallowed (this “drip” is considered pleasant by some and unpleasant by others). In a study of cocaine users, the average time taken to reach peak subjective effects was 14.6 minutes. Any damage to the inside of the nose is because cocaine highly constricts blood vessels – and therefore blood and oxygen/nutrient flow – to that area. Nosebleeds after cocaine insufflation are due to irritation and damage of mucus membranes by foreign particles and adulterants and not the cocaine itself; as a vasoconstrictor, cocaine acts to reduce bleeding.

Prior to insufflation, cocaine powder must be divided into very fine particles. Cocaine of high purity breaks into fine dust very easily, except when it is moist (not well stored) and forms “chunks,” which reduces the efficiency of nasal absorption.

Rolled up banknotes, hollowed-out pens, cut straws, pointed ends of keys, specialized spoons, long fingernails, and (clean) tampon applicators are often used to insufflate cocaine. Such devices are often called “tooters” by users. The cocaine typically is poured onto a flat, hard surface (such as a mirror, CD case or book) and divided into “bumps”, “lines” or “rails”, and then insufflated. The amount of cocaine in a line varies widely from person to person and occasion to occasion (the purity of the cocaine is also a factor), but one line is generally considered to be a single dose and is typically 35 mg (a “bump”) to 100 mg (a “rail”)[dubious – discuss]. As tolerance builds rapidly in the short-term (hours), many lines are often snorted to produce greater effects.

A study by Bonkovsky and Mehta reported that, just like shared needles, the sharing of straws used to “snort” cocaine can spread blood diseases such as Hepatitis C.

Injection
Drug injection provides the highest blood levels of drug in the shortest amount of time. Subjective effects not commonly shared with other methods of administration include a ringing in the ears moments after injection (usually when in excess of 120 milligrams) lasting 2 to 5 minutes including tinnitus & audio distortion. This is colloquially referred to as a “bell ringer”. In a study of cocaine users, the average time taken to reach peak subjective effects was 3.1 minutes. The euphoria passes quickly. Aside from the toxic effects of cocaine, there is also danger of circulatory emboli from the insoluble substances that may be used to cut the drug. As with all injected illicit substances, there is a risk of the user contracting blood-borne infections if sterile injecting equipment is not available or used. Additionally, because cocaine is a vasoconstrictor, and usage often entails multiple injections within several hours or less, subsequent injections are progressively more difficult to administer, which in turn may lead to more injection attempts and more sequelae from improperly performed injection.

An injected mixture of cocaine and heroin, known as “speedball” is a particularly dangerous combination, as the converse effects of the drugs actually complement each other, but may also mask the symptoms of an overdose. It has been responsible for numerous deaths, including celebrities such as John Belushi, Chris Farley, Mitch Hedberg, River Phoenix and Layne Staley.

Experimentally, cocaine injections can be delivered to animals such as fruit flies to study the mechanisms of cocaine addiction.

Inhalation
Inhalation or smoking is one of the several means cocaine is administered. Cocaine is smoked by inhaling the vapor by sublimating solid cocaine by heating. In a 2000 Brookhaven National Laboratory medical department study, based on self reports of 32 abusers who participated in the study,”peak high” was found at mean of 1.4min +/- 0.5 minutes.
Smoking freebase or crack cocaine is most often accomplished using a pipe made from a small glass tube, often taken from “Love roses,” small glass tubes with a paper rose that are promoted as romantic gifts. These are sometimes called “stems”, “horns”, “blasters” and “straight shooters”. A small piece of clean heavy copper or occasionally stainless steel scouring pad – often called a “brillo” (actual Brillo pads contain soap, and are not used), or “chore”, named for Chore Boy brand copper scouring pads, – serves as a reduction base and flow modulator in which the “rock” can be melted and boiled to vapor. Crack smokers also sometimes smoke through a soda can with small holes in the bottom.

Crack is smoked by placing it at the end of the pipe; a flame held close to it produces vapor, which is then inhaled by the smoker. The effects, felt almost immediately after smoking, are very intense and do not last long – usually 5 to 15 minutes.

When smoked, cocaine is sometimes combined with other drugs, such as cannabis, often rolled into a joint or blunt. Powdered cocaine is also sometimes smoked, though heat destroys much of the chemical; smokers often sprinkle it on cannabis.

The language referring to paraphernalia and practices of smoking cocaine vary, as do the packaging methods in the street level sale.

Suppository
Little research has been focused on the suppository (anal or vaginal insertion) method of administration, also known as “plugging”. This method of administration is commonly administered using an oral syringe. Cocaine can be dissolved in water and withdrawn into an oral syringe which may then be lubricated and inserted into the anus or vagina before the plunger is pushed. Anecdotal evidence of its effects are infrequently discussed, possibly due to social taboos in many cultures. The rectum and the vaginal canal is where the majority of the drug would likely be taken up, through the membranes lining its walls.