Synthetic Drug Cocktails Overtake New Substances as the Primary Health Threat in Latin America
- Gastón CalvoInternational news journalist at Infobae (Infobae América).
Photo: Magnific
A report from the Inter-American Drug Observatory reveals that the market is no longer defined by the emergence of new compounds, but by toxic and unpredictable combinations spreading at hemispheric speed.
Synthetic drug mixtures — not the appearance of new molecules — now represent the most serious public health threat in the Americas. This is the central conclusion of the latest report from the Inter-American Drug Observatory (OID), the research unit of the Inter-American Drug Abuse Control Commission (CICAD) of the OAS, released this year.
Marya Hynes, head of the OID and general coordinator of the study, explained with precision: "The market is no longer defined by the emergence of new substances, but by the proliferation of increasingly complex and unpredictable mixtures."
The diagnosis marks a turning point. For years, the debate on synthetic drugs revolved around identifying new psychoactive substances. Today, the problem is different: the combination of known compounds in variable proportions, with no quality control, sold under brand names that do not reflect their actual composition. "Unpredictability itself has become the main risk," Hynes emphasised.
A market that mutated in three stages
Data from the Americas Early Warning System (SATA), active since 2019, clearly traces the market's evolution. In the first phase, between 2019 and 2021, alerts pointed to individual substances: MDMA, synthetic cannabinoids, phenethylamines. From 2022 to 2023, a second stage began, with the appearance of more complex mixtures combining opioids, stimulants, sedatives, benzodiazepines, dissociatives and industrial additives. In the 2024-2025 period, the market is already dominated by polydrugs and reformulated products, with "tusi" as an emblematic case.
"This reflects a structural change," Hynes said. "We are no longer talking only about new drugs, but about new combinations that adapt rapidly and cross borders at great speed."
SATA alerts have moved from describing single substances to documenting combinations, increasing both toxicity and the difficulty of anticipating adverse effects.
Tusi: a product with no fixed composition
No example illustrates this phenomenon better than "tusi" or "pink cocaine". It is marketed as if it were a unique, defined product, but may contain very different combinations depending on the batch, the country, or even the seller. OID analyses detected ketamine, MDMA, methamphetamine, caffeine, synthetic cathinones, benzodiazepines and opioids in tusi samples. In some cases, a single sample contained up to nine different substances.
"The user does not know what they are taking, nor in what dose," Hynes warned. The clinical consequences are severe: accidental overdoses, unpredictable drug interactions, and complications difficult to treat in emergency rooms, where doctors also do not know which substances they are dealing with. "It combines stimulant and depressant effects, can cause cardiovascular or neurological overload, and complicates medical response," the expert specified.
The spread of tusi in Central and South America is not an isolated phenomenon. It follows the same logic that defines today's market: reformulated products with shifting commercial identities that adapt to different contexts and expand rapidly through transnational organised crime networks.
Nitazenes and xylazine: the southward expansion
The OID report also documented the spread of two types of substances that until recently were an almost exclusive problem in North America: nitazenes and xylazine. The former are extremely potent synthetic opioids, even more potent than fentanyl, first detected in the northern region of the continent in 2022 and with a growing presence in South America. The latter is a veterinary sedative that frequently appears as an adulterant in fentanyl supplies.
"We are seeing the expansion of extremely potent substances," Hynes explained. The impact is multiple: increased risk of death, difficulty in reversing overdoses with naloxone — the standard antidote — and new clinical complications such as skin lesions or necrosis in users with a history of xylazine use. "Its appearance outside North America indicates that these risks are expanding regionally," she warned.
Medetomidine, another veterinary sedative, follows the same pattern. Its presence in fentanyl supplies adds an additional layer of danger: since it is not an opioid, it does not respond to conventional reversal treatments, raising overdose lethality.
The case of Argentina in 2022: 24 dead in 48 hours
The episode that best illustrates the consequences of these dynamics occurred in Argentina in 2022. The circulation of cocaine adulterated with carfentanil — an ultrapotent synthetic opioid — caused 24 deaths and 80 hospitalisations in just 48 hours. Authorities issued an emergency epidemiological alert, and forensic analyses confirmed the presence of the compound.
For Hynes, that case was a lesson in what can happen when detection systems fail or react too late. "It demonstrated the importance of having functional early warning systems, strengthening coordination between health, forensic and security services, and issuing public alerts quickly," she said. The report is categorical: "Consequences can be immediate and massive when a toxic mixture is not detected in time."
Detect earlier, not just more
Faced with this scenario, the OID proposes that the institutional response must evolve in three directions. First, strengthen national early warning systems so that all countries can identify substances quickly. Second, integrate health, forensic and security data to turn information into actionable intelligence. Third, accelerate regional and international information sharing, because the speed of the market demands equally rapid responses.
"The priority should not be only to detect more, but to detect earlier, share information better, and act faster. That is precisely the strategic value of early warning systems," Hynes noted. SATA, as a hemispheric platform, enables countries to share alerts, identify diffusion patterns, and anticipate risks before they escalate.
The institutional challenge is to move from reactive models to anticipatory systems. Hynes was direct: "Real-time information sharing is absolutely central. Transnational organised crime trafficking synthetic drugs does not respect borders." That asymmetry — between the speed of the illegal market and the slowness of state responses — is, according to the report, the gap that the region's countries must close urgently.
An additional difficulty is the inequality in detection capacity. In some countries, such as Bolivia, Peru, or Ecuador, early warning systems are still being developed. In others, such as Belize, Cuba, or Venezuela, they do not exist at all. This fragmentation delays the collective response to threats that, by definition, do not recognise borders.
Sources:
Synthetic drug mixtures — not the appearance of new molecules — now represent the most serious public health threat in the Americas. This is the central conclusion of the latest report from the Inter-American Drug Observatory (OID), the research unit of the Inter-American Drug Abuse Control Commission (CICAD) of the OAS, released this year.
Marya Hynes, head of the OID and general coordinator of the study, explained with precision: "The market is no longer defined by the emergence of new substances, but by the proliferation of increasingly complex and unpredictable mixtures."
The diagnosis marks a turning point. For years, the debate on synthetic drugs revolved around identifying new psychoactive substances. Today, the problem is different: the combination of known compounds in variable proportions, with no quality control, sold under brand names that do not reflect their actual composition. "Unpredictability itself has become the main risk," Hynes emphasised.
A market that mutated in three stages
Data from the Americas Early Warning System (SATA), active since 2019, clearly traces the market's evolution. In the first phase, between 2019 and 2021, alerts pointed to individual substances: MDMA, synthetic cannabinoids, phenethylamines. From 2022 to 2023, a second stage began, with the appearance of more complex mixtures combining opioids, stimulants, sedatives, benzodiazepines, dissociatives and industrial additives. In the 2024-2025 period, the market is already dominated by polydrugs and reformulated products, with "tusi" as an emblematic case.
"This reflects a structural change," Hynes said. "We are no longer talking only about new drugs, but about new combinations that adapt rapidly and cross borders at great speed."
SATA alerts have moved from describing single substances to documenting combinations, increasing both toxicity and the difficulty of anticipating adverse effects.
Tusi: a product with no fixed composition
No example illustrates this phenomenon better than "tusi" or "pink cocaine". It is marketed as if it were a unique, defined product, but may contain very different combinations depending on the batch, the country, or even the seller. OID analyses detected ketamine, MDMA, methamphetamine, caffeine, synthetic cathinones, benzodiazepines and opioids in tusi samples. In some cases, a single sample contained up to nine different substances.
"The user does not know what they are taking, nor in what dose," Hynes warned. The clinical consequences are severe: accidental overdoses, unpredictable drug interactions, and complications difficult to treat in emergency rooms, where doctors also do not know which substances they are dealing with. "It combines stimulant and depressant effects, can cause cardiovascular or neurological overload, and complicates medical response," the expert specified.
The spread of tusi in Central and South America is not an isolated phenomenon. It follows the same logic that defines today's market: reformulated products with shifting commercial identities that adapt to different contexts and expand rapidly through transnational organised crime networks.
Nitazenes and xylazine: the southward expansion
The OID report also documented the spread of two types of substances that until recently were an almost exclusive problem in North America: nitazenes and xylazine. The former are extremely potent synthetic opioids, even more potent than fentanyl, first detected in the northern region of the continent in 2022 and with a growing presence in South America. The latter is a veterinary sedative that frequently appears as an adulterant in fentanyl supplies.
"We are seeing the expansion of extremely potent substances," Hynes explained. The impact is multiple: increased risk of death, difficulty in reversing overdoses with naloxone — the standard antidote — and new clinical complications such as skin lesions or necrosis in users with a history of xylazine use. "Its appearance outside North America indicates that these risks are expanding regionally," she warned.
Medetomidine, another veterinary sedative, follows the same pattern. Its presence in fentanyl supplies adds an additional layer of danger: since it is not an opioid, it does not respond to conventional reversal treatments, raising overdose lethality.
The case of Argentina in 2022: 24 dead in 48 hours
The episode that best illustrates the consequences of these dynamics occurred in Argentina in 2022. The circulation of cocaine adulterated with carfentanil — an ultrapotent synthetic opioid — caused 24 deaths and 80 hospitalisations in just 48 hours. Authorities issued an emergency epidemiological alert, and forensic analyses confirmed the presence of the compound.
For Hynes, that case was a lesson in what can happen when detection systems fail or react too late. "It demonstrated the importance of having functional early warning systems, strengthening coordination between health, forensic and security services, and issuing public alerts quickly," she said. The report is categorical: "Consequences can be immediate and massive when a toxic mixture is not detected in time."
Detect earlier, not just more
Faced with this scenario, the OID proposes that the institutional response must evolve in three directions. First, strengthen national early warning systems so that all countries can identify substances quickly. Second, integrate health, forensic and security data to turn information into actionable intelligence. Third, accelerate regional and international information sharing, because the speed of the market demands equally rapid responses.
"The priority should not be only to detect more, but to detect earlier, share information better, and act faster. That is precisely the strategic value of early warning systems," Hynes noted. SATA, as a hemispheric platform, enables countries to share alerts, identify diffusion patterns, and anticipate risks before they escalate.
The institutional challenge is to move from reactive models to anticipatory systems. Hynes was direct: "Real-time information sharing is absolutely central. Transnational organised crime trafficking synthetic drugs does not respect borders." That asymmetry — between the speed of the illegal market and the slowness of state responses — is, according to the report, the gap that the region's countries must close urgently.
An additional difficulty is the inequality in detection capacity. In some countries, such as Bolivia, Peru, or Ecuador, early warning systems are still being developed. In others, such as Belize, Cuba, or Venezuela, they do not exist at all. This fragmentation delays the collective response to threats that, by definition, do not recognise borders.
Sources:
- https://www.swissinfo.ch/spa/la-mezcla-%22impredecible%22-de-drogas-es-el-nuevo-riesgo-para-las-am%C3%A9ricas%2C-alerta-la-oea/91298321
- https://www.oas.org/ext/DesktopModules/MVC/OASDnnModules/Views/Item/Download.aspx?id=1452&lang=2&type=1&utm_source
- UNODC. (2026). Monitoring Reports on Synthetic Opioids and Emerging Adulterants.
- United Nations Office on Drugs and Crime (UNODC). (2026). New Global Developments: Synthetic Opioids.
- Inter-American Drug Observatory and Early Warning System of the Americas.
- Inter-American Drug Abuse Control Commission. (2026). Synthetic Drug Trends in the Americas (2019-2025). Organization of American States.
- Inter-American Drug Observatory. (2026). Early Warning System of the Americas (EWSA). Organization of American States.
- United Nations Office on Drugs and Crime. (2026). New Global Developments: Synthetic Opioids. Vienna: UNODC.
- United Nations Office on Drugs and Crime. (2022). Synthetic Drugs and New Psychoactive Substances in Latin America and the Caribbean. Vienna: UNODC.
- Hynes, M. (2026). Personal interview granted to the author of this article.
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