Cultural History and Pharmacology of Cocaine

Cocaine is a naturally occurring alkaloid derived from coca leaves, used for millennia.
Historically used for mystical and shamanistic purposes and as a daily treatment to boost energy and increase tolerance to altitude.
Availability of formal studies on coca and altitude sickness is surprisingly limited, with anecdotal and informal testimonials more common.

Coca leaves are often combined with ash and held in the mouth for 30-60 minutes.
Effects noted:
- Mild stimulation
- Mild analgesia
- Possible reduction of altitude sickness symptoms, potentially due to plant pigments (flavonoids) increasing nitric oxide, promoting arterial dilation and enhancing oxygenation to the brain; however, this is not rigorously confirmed in studies.

Coca remained mainly in South America until the extraction of cocaine in the mid-1800s.
Coca leaves contain 0.6% to 1.8% cocaine alkaloid.
Cocaine is extracted to create a paste (80% alkaloid) and converted to cocaine hydrochloride, making it water-soluble for absorption via mucosal linings or injection.
Recognized addictive properties of cocaine emerged by the late 1800s, influencing public perception by the early 1900s.

Cocaine was largely suppressed until the 1970s in the U.S., where it became the preferred drug.
The common method of use was snorting cocaine hydrochloride, which cannot be smoked due to heat damaging its structure.
When converted to freebase, it can be smoked as “crack” cocaine.
Recent trends show cocaine and crack use are in decline based on the "Monitoring the Future" study.
Over 40,000 students across lower 48 states were sampled:
- Example numbers include 16,200 eighth graders, 14,000 tenth graders, and 12,800 twelfth graders.
- By 2025, a slow decline in use among these grades noted, with the exception of a potential increase for 12th graders in 2024.

The so-called crack epidemic occurred in the U.S. during the 1980s to early 1990s, amid public panic.
Usage statistics:
- NIDA findings showed crack use: 1986 (4.1%), 1988 (3.1%), 1993 (1.5%)—suggesting a more complex picture rather than a true epidemic.
Cocaine and crack addiction prevalence observed in 5%-15% of users, who form a high-risk group influenced by other factors.
Rapid onset of action with crack contributes to its higher addiction potential.

Contrary to the belief of widespread harm, recent literature reviews suggest no strong evidence linking prenatal cocaine exposure to unique developmental effects, often confounded by other substance abuses (tobacco, alcohol, etc.).

Cocaine and crack are pharmacologically the same, with only hydrochloride removal making crack smokable.
Routes of administration impact pharmacokinetics with different plasma concentration outcomes:
- Intravenous and smoked cocaine yield plasma concentrations of $500-1000 ext{ ng/ml}$ .
- Nasal cocaine results in $100-500 ext{ ng/ml}$ .
Cocaine's half-life is variable, ranging from 16-90 minutes.

Primary Mechanism: Cocaine inhibits the reuptake of dopamine (DA), norepinephrine (NE), and serotonin (5-HT), increasing their synaptic availability.
- Long-term, higher neurotransmitter levels lead to presynaptic reductions in their production, indicating potential for pharmacodynamic tolerance.
Secondary Mechanism: At high doses, cocaine blocks Na+ channels in neurons, resulting in reduced neuron firing, similar to local anesthetics like procaine (Novocain) and lidocaine (Xylocaine) that lack psychoactive effects despite similar actions.

Cocaine increases DA levels in the nucleus accumbens, enhancing rewarding effects (Pettit & Justice, 1991).
Effects reminiscent of sympathetic nervous system activation (sympathomimetic effects), impacting mood and alertness.
Cocaine's impact is dose-dependent, with lower doses producing mild effects, and higher doses leading to severe effects such as insomnia.

Data suggests cocaine is not universally addictive; moderate reinforcement seen when preferred, dependent on available alternatives.
Monkey study findings:
- Response defined by preference for cocaine versus food, indicating preference is relative to available reinforcers.
Human studies confirm that while cocaine can act as a reinforcer, its impact is not absolute; larger monetary incentives decreased preference for cocaine.
Key findings include that access to non-drug alternatives significantly reduces cocaine use (Higgins et al., 1994).

Concurrent use of CO and ETH leads to the formation of cocaethylene, a psychoactive and cardiotoxic metabolite.
Cocaethylene increases the risk of drug-induced cardiac events.