Acids, Bases and Cocaine Addicts Quiz

Study Notes

Cocaine is a molecule made up of C, H, O and N atoms.
Cocaine is a weak base and, in solution, it exists in 2 forms in an equilibrium: the free base and the acid salt.
The predominant form in solution depends on the pH of the solution.
In its free base form, the molecule is uncharged (unionized or non-polar) and is not readily dissolved in an aqueous medium (water).
When the free base is reacted with hydrochloric acid (low pH), the N accepts a H+ and forms the hydrochloride salt.
In this form, cocaine is ionized and is water soluble.
Because the hydrochloride salt dissolves in solution, it can be snorted or injected.
However, the ionized form (salt) can not be smoked because it is so stable at high temperatures, it does not volatilize (vaporize) in the smoke.
In contrast, the free base form of cocaine (unionized) is easily volatilized by high temperatures so that it can be breathed into the lungs.
The free base is usually made by mixing the hydrochloride salt of cocaine with sodium bicarbonate (baking soda).
When the liquid mixture is evaporated, the solid “lump” of cocaine can be crushed up and heated (“crack”).
Free base heroin or amphetamine (“ice”) are made the same way.
Injection is the easiest way to get cocaine or other drugs into the bloodstream, and smoking cocaine enables it to enter the bloodstream almost as fast as injecting.
The blood brain barrier restricts the entry of only certain molecules (and drugs) into the brain, protecting it from dangerous compounds.
Cocaine diffuses through special epithelial cells (mucosal cells) lining the nasal passages into nearby capillaries and is absorbed into the bloodstream fairly quickly.
After cocaine leaves the gut, it travels to the liver, then to the heart, and finally to the rest of the body.
Cocaine produces a strong, short-lived euphoria when smoked or snorted.
The abuse potential of cocaine is high when it is smoked crack, because the drug enters the brain quickly.
When snorted, cocaine takes longer to enter the brain and the high lasts longer.
Cocaine is less likely to be abused when it is orally ingested, because relatively little cocaine reaches the brain.