How Synthetic Amphetamines Gained Popularity

In an interview published on April 18, 2021, French President Emmanuel Macron called for “launching a major national debate on drug use.” The interview focused primarily on the law enforcement aspect of drug control policy, and the effectiveness of the proposed measures immediately became a subject of controversy.

Edouard TUAILLON, University of Montpellier

© Couperfield - stock.adobe.com

Nevertheless, the debate should lead to a consensus on recognizing addiction as a major public health risk.

The use of amphetamines (stimulant psychotropic drugs), which has been documented for over a century, must not be overlooked in this context. Indeed,the emergence of new forms of addiction associated with amphetamines from the cathinone family is now a cause for concern in France.

A Brief (Medical) History of Synthetic Amphetamines

The first chemical purification of an amphetamine (ephedrine) is attributed to Nagai Nagayoshi, a Japanese pharmacist, and is believed to date back to 1885. The synthesis of ecstasy (or MDMA, short for 3,4-methylenedioxy-N-methylamphetamine) by Merck Laboratories dates back to 1912, and the first synthesis of a cathinone (β-ketoamphetamine) to 1929.

In the first half of the20th century, the effects of these synthetic molecules captivated chemists and sparked interest in the medical community.

Their sympathomimetic (stimulant), anorexigenic (appetite suppressant), and psychostimulant (performance-enhancing) effects led to the commercialization of the first amphetamine-based drugs: a bronchodilator, Benzedrine®, in 1934 in the United States (an amphetamine sulfate), an appetite suppressant with Obetrol® starting in the 1950s, also in the United States (a combination of amphetamine salts), and an energy booster with Pervitin® (a methamphetamine) in Germany in the late 1930s.

A potent form of methamphetamine, this compound was available over the counter at pharmacies and widely distributed to German troops during World War II. Thanks to its long-lasting stimulant effects, it is believed to have played a decisive role early in the war in the success of theblitzkrieg strategy, enabling soldiers to march and fight without sleep for several days.

The medical use of amphetamine derivatives continued after the war. By the end ofthe 20th century, psychostimulants were being prescribed to treat attention deficits, such as Ordinator® (which was withdrawn from the market in 1997), as well as appetite suppressants like Isoméride® and Mediator® (prescribed for metabolic disorders, particularly diabetes). They were withdrawn from the market in 1997 and 2009, respectively, due to serious adverse effects that led to several convictions against Servier Laboratories.

Today, the following medications remain available but with significant prescription restrictions: Zyban®, as an aid for smoking cessation, and Ritalin® for attention-deficit/hyperactivity disorder in children and narcolepsy in adults. This latter medication, whose medical benefits have been confirmed by the French National Authority for Health, is likely the one that has been most medically beneficial to date.

From the natural role to the first uses

The use of amphetamines did not begin with their discovery through synthetic chemistry. These compounds occurnaturally in certain plants, where they serve as defense mechanisms against herbivores, much like other plant alkaloids.

Thus, ephedrine was purified from a plant used in traditional Chinese medicine – Ephedra sinica. But the best-known plant, and the most significant in societal and economic terms, is khat, whose Latin name is Catha edulis, whose freshly harvested leaves contain β-ketoamphetamine or cathinone (which degrades rapidly after harvest).

Khat is believed to originate from Ethiopia, where it grows wild in temperate regions located at altitudes of over 1,500 meters and with adequate rainfall. These growing requirements, similar to those of Arabica coffee, have allowed khat cultivation to spread to certain areas of the Arabian Peninsula, East Africa, and Madagascar.

The use of khat may date back to before the year 1000, although it appears to have become more widespread starting in the15th century. In Yemen, where approximately 60% of the population uses it (30% in Ethiopia and Somalia), its cultivation accounts for nearly 6% of the gross domestic product and employs 14% of the workforce.

Seized khat branches
Khat leaves must be consumed in large quantities and quickly, as the cathinone they contain breaks down rapidly. This complicates their use.
DEA

For consumers, accessing the psychoactive effects of cathinones is not easy. First, they must obtain freshly cut branches and then chew the bitter leaves for a long time to extract the active ingredient. A 500-gram bundle of branches—equivalent to about 150 grams of leaves—requires two hours of chewing.

Consuming khat in the traditional way therefore takes time, but also money—at the expense of children’s health or education.

From ecstasy to synthetic cathinones

Compared to khat, synthetic amphetamines have significantly stronger psychoactive effects, while being easier to produce, transport, store, and consume.

In France, amphetamines have been classified as narcotics since 1967. The rise in their use as a recreational drug beginning in the 1990s is linked to the emergence of electronic music and rave parties: ecstasy (MDMA) was then used as a party drug, valued for its energizing effects and its ability to facilitate social interaction.

The turn of the 21st century, meanwhile, was marked by the emergence of the online market for synthetic drugs—or new psychoactive substances (NPS). These include various forms of psychotropic substances, primarily: cannabinoids, amphetamines, opioids, ketamines, and, starting in the 2010s, synthetic cathinones—the beefed-up cousins of the alkaloid found in khat.

With these substances, amphetamines would move beyond occasional and marginal use by a small number of experimenters to reach a large, socially well-integrated population of regular users.

A drug that activates the reward system

To understand the dangerous rise in popularity of cathinones, we need to examine how amphetamines affect our brains.

The structure of cathinones is similar to that of dopamine, a neurotransmitter that plays a major role in the reward system. The reinforcement/reward system is present in many animals (fish, birds, mammals), where it promotes behaviors essential to the survival of the species: eating, learning, reproducing, and socializing. Cathinones act directly on this system.

After ingestion, inhalation, or injection, cathinones—which are small molecules—easily cross the blood-brain barrier that protects the brain. They then interact with dopamine neurons, inhibiting dopamine reuptake and promoting its release. Through these mechanisms, cathinones cause a significant increase in dopamine levels. In rats, 40 minutes after administration of a standard dose of cathinone, the increase in dopamine levels is approximately 500%.

Diagram illustrating the mechanism of action of cathinones
Cathinones affect the reward system by interacting with dopamine neurons, a neurotransmitter involved in the sensation of pleasure.
E. Tuaillon, Provided by the author

This surge of dopamine activates the reward system’s circuits. It is these stimulating and entactogenic effects (which alter the desire for physical contact) that users seek, particularly when using the substance for sexual purposes.

Without further use, dopamine levels drop rapidly and return to normal after about 180 minutes. A brief withdrawal syndrome is frequently reported by users 24 to 48 hours after use; it is characterized in particular by fatigue and a general sense of unease (dysphoria).

Amphetamine use inthe 20th century was thus characterized not only by greater accessibility, thanks to chemical synthesis, but also by the desire to enhance one’s physical abilities—often in a party setting.

In this age of augmented reality and instant gratification, cathinones have come to embody a deceptive promise of easily satisfying our desires…The Conversation

Edouard TUAILLON, University Professor and Hospital Physician. Areas of expertise: infectious diseases, virology, sexual health, University of Montpellier

This article is republished from The Conversation under a Creative Commons license. Readthe original article.