Answer: Cocaine is used medically as an anesthetic, vasoconstrictor, and as a diagnostic tool.
Cocaine is the main psychoactive ingredient of the leaves of the plant Erythroxylin coca. Most of the E. coca is grown in three countries in South America. The chemical can be isolated from the leaves, and used in its chemical form. The United States is the number 1 consumer of cocaine in the world.
Much of the cocaine use is illegal and for recreational purposes. Cocaine is a very well known drug of abuse. It is generally considered to have some of the highest risks among the common drugs of abuse. Cocaine has a very high toll on society, as chronic use can cause a variety of health problems.
Historically, cocaine was considered to be a medical substance. Sigmund Freud, for example, was a proponent of using cocaine for a variety of disorders, ranging from anxiety, fatigue, and heroin addiction. Cocaine was added into wine preparations, such as the Italian wine Vin Mariani. Around that same time, a Georgian named John Pemberton created a cocaine infused drink without the alcohol. Instead, he added the extract from the kola nut and carbonation. This drink was called Coca-Cola. In the early 1900’s, soda machines were only found in pharmacies. When cocaine was banned by government regulation, it was removed from these products.
Medical uses of cocaine
However, even today, there are medical applications for cocaine. The main pharmacological actions of cocaine are to decrease the reuptake of monoamine neurotransmitters, including dopamine, norepinephrine, and serotonin. The decrease of reuptake results in more activity at all these receptors.
For one, topical application of cocaine is an anesthetic. It is used in nasal surgery or lacrymal duct surgery. Cocaine blocks voltage-gated sodium channels. By doing so, it blocks the pain signals from reaching the brain, therefore preventing the brain from experiencing pain. Another drug that acts as an anesthetic in the same mechanism is lidocaine or procaine, which are also inhibitors of voltage-gated sodium channels. Before these compounds were developed artificially, cocaine was used in several types of surgeries.
Cocaine can also be used as a diagnostic test to evaluate someone’s pupillary reaction. In particular, it is useful for testing the presentation of Horner’s syndrome. In Horner’s syndrome, there is a deficit in the sympathetic trunk that innervates part of the face. As a result, a person with Horner’s syndrome may present with miosis, anhydrosis, or other issues with the pupillary reflex. Horner’s syndrome is often the result of some injury to the sympathetic trunk.
Cocaine is used to diagnose for Horner’s syndrome by putting drops into the eye. When cocaine is introduced to the eyes, it causes the pupils to dilate in a normal patient. However, when a person has Horner’s syndrome, their pupils will not dilate in response to the cocaine. Because these patients have a deficit with the sympathetic trunk, no degree of norepinephrine reuptake blockade will cause the pupils to dilate.
Because cocaine still has medical applications today, it is classified as a Schedule II drug under the Controlled Substances Act. Drugs classified as Schedule II have a very high addiction potential, but still have medical applications. Compare this with Schedule I drugs, which have an equally high addiction potential but no known medical applications. Many of the prescription opioid drugs, such as fentanyl, morphine, or hydrocodone, are also Schedule II drugs.
Using cocaine medically has downsides. It is well known that cocaine is a sympathomimetic, meaning that it can trigger sympathetic nervous system activity. Norepinephrine is the primary neurotransmitter that is used in the sympathetic response, which is also called the “flight or fright” response. One potential side effect is the potentially dangerous increase in heart rate that can lead to other unpredictable cardiovascular changes. Other symptoms of excessive sympathomimetics can include nausea, dry mouth, or constipation.