Little-known syndrome exposes impacts of chronic cannabis use on health

A study published in the JAMA Network Open draws attention to the growing number of hospital visits related to cannabinoid hyperemesis syndrome, a condition associated with intense and prolonged cannabis use. 

The research analyzed data from emergency department visits in the United States between 2016 and 2022 and identified a consistent increase in cases consistent with the condition over the period.

Characterized by recurrent episodes of intense nausea, persistent vomiting, and abdominal pain, the syndrome is still poorly recognized outside the medical community, which hinders the diagnosis and proper monitoring of patients. During the years of the Covid-19 pandemic, the records increased more sharply and remained elevated even after this period.

According to Dr. Guilherme Nery, a postgraduate in Cannabinoid Medicine, the main differentiator of the syndrome from other common causes of vomiting is directly related to the substance's usage history. “The big point that sets cannabinoid hyperemesis apart from other syndromes is the recent and recurrent use of cannabis, mainly THC,” he explains.

Youthful adults account for the majority of cases

According to the survey, the highest incidence of visits occurred among young adults, especially in the 18 to 35 age group, with a predominance among men. The study also pointed out demographic and regional variations, indicating that the phenomenon is not distributed homogeneously across the country.

In emergency care, the syndrome usually manifests cyclically, with recurrent episodes of intense vomiting interspersed with periods of improvement. Another relevant clinical sign, according to Nery, is the compulsive behavior of seeking hot baths.

“Some patients find significant relief from symptoms in hot baths. We believe that peripheral vasodilation helps mobilize circulating cannabinoids to adipose tissue, temporarily reducing their concentration in the blood,” says the doctor. Although not exclusive to the syndrome, this pattern is considered an important clue in clinical evaluation.

Diagnosis remains a challenge

Researchers used clinical criteria to identify cases since, for much of the analyzed period, there was no specific diagnostic code for the syndrome in international disease classification systems. This contributed to underreporting and the classification of these visits as nonspecific gastrointestinal disorders.

In emergency room practice, other signs reinforce suspicion of the syndrome, such as a poor response to conventional antiemetics, multiple visits to the emergency service, dehydration, and electrolyte disturbances resulting from repeated vomiting.

Cessation of use is central to treatment

According to Dr. Guilherme Nery, discontinuation of cannabis use is essential for the definitive control of the syndrome. “Abstinence is mandatory to resolve the condition sustainably. If the patient improves in the emergency room but continues to use, the chance of recurrence is high,” he emphasizes.

The time without cannabinoids needed varies from person to person, but usually between 15 and 45 days are sufficient to interrupt the cycle of crises. During acute episodes, measures such as intravenous hydration, electrolyte correction, use of topical capsaicin, and medications like haloperidol can help reduce suffering, although they do not replace cessation of use.

Official recognition can expand diagnosis and care

The study's release comes at a time when the World Health Organization (WHO) has officially recognized cannabinoid hyperemesis syndrome, creating a specific code in the International Classification of Diseases. This measure should facilitate case registration, support new research, and qualify the clinical approach in emergency services.

Despite the situation, the doctor emphasizes that cannabis and its derivatives have a consolidated therapeutic use. “They are medications that may not be compatible with a portion of the population. When this happens, it is important to seek therapeutic alternatives considering the individual,” he concludes.