Crack is actually a less pure sort of freebase cocaine. Unlike old-fashioned free-base, however, its production doesn't involve any flammable solvents.
Crack is usually made by mixing two parts of cocaine hydrochyloride with one part baking soda in about 20 ml of water. The solution is then heated gently until white precipitates form. Heating is halted when precipitation stops. The precipitate is filtered and retained. The precipitate may then be washed with water; this procedure is usually omitted in the street product. The product may then be dried for 24 hours under a heat-lamp. Crack is then cut or broken into small 'rocks' weighing a few tenths of a gram.
The traditional method of taking cocaine in the West involves snorting the hydrochloride salt. But absorption through the nasal mucosa is relatively modest. This is because their surface-area is small and cocaine is vasoconstrictive. Freebase, on the other hand, is smoked and inhaled directly into the lungs. Therefore much higher doses are possible. Inhalation is followed by an intense euphoric rush. The euphoria doesn't last long. The user becomes irritable and craves more of the drug.
Chronic cocaine-use causes a decrease in the production of enkephalin, one of the brain's natural opioids. This in turn causes a compensatory increase in the number of mu-receptors. The number of unoccupied mu-receptors may be associated with the craving and abstinence syndrome.
After chronic exposure to cocaine, the number of post-synaptic dopamine receptors in the CNS is reduced. The amount of dopamine transporter protein is increased. Tolerance to cocaine's effects does exist over prolonged use; but the extent of this physiological adaptation is relatively modest. The cocaine-user still gets high; but in the absence of cocaine, his pre-synaptic neurons sequester dopamine in the synaptic cleft with greater efficiency. This may induce depression, and sometimes profound despair.
No one ever feels contented after taking cocaine. They just want more.
The high from crack cocaine is intensely rewarding. So it's reckless to try the drug at all - at least until one's death-bed] - because it's extraordinarily hard to forget. If one succumbs to curiosity, then other things in life can easily pall in comparison. Tragically, family and loved ones may suffer almost as much as the addict.
So is a fallen crackhead inescapably doomed? Or are there ways (s)he can escape from the abyss?
Perhaps. Most of the GIs who got hooked on unmistakably physically addictive heroin in Vietnam kicked the habit when they returned to the USA. They quit, often without undue difficulty, because most of the "conditioned cues and reinforcers" associated with drug-use in South-East Asia were missing back home.
Thus a complete change of environment, especially in the company of supportive family and (drug-free) friends, can help break a user's self-destructive cycle of coke-binges. Good food, particularly an idealised stone-age diet fruit, vegetables, nuts, seeds, wholemeal bread, pasta, rice etc should help too. Regular vigorous exercise is useful as well and probably Faith In Jesus, though this isn't always a realistic option
Some drug-pundits recommend Total Abstinence: "Just Say No." The ex-addict is encouraged to renounce "unnatural" chemical highs altogether. This course of action may indeed be prudent. Unfortunately, godliness, virtue and clean living aren't always the recipe for a happy life either.
For many cocaine-users have a pre-existing psychiatric disorder - even by today's dismally impoverished conception of mental health. In effect, they are self-medicating, even if they ostensibly take coke "for kicks". So in place of cocaine, clinically useful mood-brighteners (e.g. desipramine, a noradrenaline reuptake blocker; or more daringly, amineptine, a dopamine reuptake blocker) and/or anti-anxiety agents may be considered instead.
Alternatively, if the user wishes to Say No To Drugs completely, then a "natural", gentle mood-brightener and anti-anxiety agent, hypericum(St John's wort), may be taken indefinitely. Unfortunately, this traditional herbal remedy is not a dependable cure for deep melancholic depression - coke-induced or otherwise.
Inevitably, today's ordinary mood-brighteners, whether herbal or clinical, won't stand comparison with tomorrow's designer-drugs. Nor will they deliver the rapturous but addictive rush of a fast-acting euphoriant. And they yield desperately little joy compared to the lifetime of genetically pre-programmed superhealth on offer to our descendants. But often dirty stopgaps are better than nothing at all. For our genes didn't design us to be happy.
Noded for posterity (and with full and explicit permission of the author, David Pearce), from the highly recommended