Studies have suggested cocaethylene is more euphoric, and has a higher cardiovascular toxicity than cocaine by itself.Depending on liver and kidney function, cocaine metabolites are detectable in urine. Benzoylecgonine can be detected in urine within four hours after cocaine intake and remains detectable in concentrations greater than 150 ng/mL typically for up to eight days after cocaine is used. Detection of cocaine metabolites in hair is possible in regular users until after the sections of hair grown during the period of cocaine use are cut or fall out. Pharmacodynamics
The pharmacodynamics of cocaine involve the complex relationships of neurotransmitters (inhibiting monoamine uptake in rats with ratios of about: serotonin:dopamine = 2:3, serotonin:norepinephrine = 2:5). The most extensively studied effect of cocaine on the central nervous system is the blockade of the dopamine transporter protein. Dopamine neurotransmitter released during neural signaling is normally recycled via the transporter; i.e., the transporter binds the transmitter and pumps it out of the synaptic cleft back into the presynaptic neuron, where it is taken up into storage vesicles. Cocaine binds tightly at the dopamine transporter forming a complex that blocks the transporters function. The dopamine transporter can no longer perform its reuptake function, and thus dopamine accumulates in the synaptic cleft. The increased concentration of dopamine in the synapse activates post-synaptic dopamine receptors, which makes the drug rewarding and promotes the compulsive use of cocaine.Cocaine affects certain serotonin (5-HT) receptors; in particular, it has been shown to antagonize the 5-HT3 receptor, which is a ligand-gated ion channel.
Medicalization
With the discovery of this new alkaloid, Western medicine was quick to exploit the possible uses of this plant. In 1879, Vassili von Anrep, of the University of Würzburg, devised an experiment to demonstrate the analgesic properties of the newly discovered alkaloid. He prepared two separate jars, one containing a cocaine-salt solution, with the other containing merely saltwater. He then submerged a frogs legs into the two jars, one leg in the treatment and one in the control solution, and proceeded to stimulate the legs in several different ways. The leg that had been immersed in the cocaine solution reacted very differently from the leg that had been immersed in saltwater.Karl Koller (a close associate of Sigmund Freud, who would write about cocaine later) experimented with cocaine for ophthalmic usage. In an infamous experiment in 1884, he experimented upon himself by applying a cocaine solution to his own eye and then pricking it with pins. His findings were presented to the Heidelberg Ophthalmological Society. Also in 1884, Jellinek demonstrated the effects of cocaine as a respiratory system anesthetic. In 1885, William Halsted demonstrated nerve-block anesthesia, and James Leonard Corning demonstrated peridural anesthesia. 1898 saw Heinrich Quincke use cocaine for spinal anesthesia. Popularization
In 1859, an Italian doctor, Paolo Mantegazza, returned from Peru, where he had witnessed first-hand the use of coca by the local indigenous peoples. He proceeded to experiment on himself and upon his return to Milan, he wrote a paper in which he described the effects.