What is Cannabinoid Hyperemesis Syndrome (CHS)?

From the Guidelines

Cannabinoid Hyperemesis Syndrome (CHS) is a condition characterized by recurrent episodes of severe nausea, persistent vomiting, and abdominal pain in long-term cannabis users, and the only definitive treatment for CHS is complete cessation of cannabis use, as evidenced by the most recent study 1.

Definition and Diagnosis

CHS is a disorder of gut–brain interaction included in the classification of functional gastrointestinal disorders (brain–gut axis disorders [Rome IV]) since 2016, characterized by cyclic vomiting, nausea, and abdominal pain, and in some cases, associated with prolonged bathing behavior (long hot baths or showers) 1. The clinical diagnostic criteria for CHS include a history of chronic nausea and vomiting, cannabis use, and cyclic vomiting episodes, with supportive remarks including a history or family history of migraine headaches.

Pathophysiology

The main active ingredient in cannabis, D9THC, activates 2 G-protein–coupled membrane receptors, CB1 and CB2 receptors, with CB1 receptors being the predominant receptors involved in the effects of THC resulting in nausea or vomiting, and are densely distributed in areas of the brain, such as the dorsal vagal complex, which is critically important in the neurocircuits controlling emesis 1.

Treatment

During acute episodes, treatment focuses on symptom management with:

• IV fluids for dehydration
• Antiemetics such as ondansetron 4-8mg every 8 hours or promethazine 12.5-25mg every 6 hours
• Hot showers or baths which provide temporary relief due to the effect of heat on TRPV1 receptors
• Topical capsaicin cream (0.075%) applied to the abdomen every 4-6 hours may also help by activating the same receptors
• Benzodiazepines like lorazepam 1-2mg can be used for associated anxiety
• Haloperidol 2.5-5mg IV or droperidol 0.625-1.25mg IV have shown effectiveness in some cases, as reported in the study 1.

Prognosis

Patients should understand that symptoms typically resolve within 24-48 hours of supportive care but will recur unless cannabis use is discontinued permanently, and recovery can take weeks to months after cannabis cessation, with some patients experiencing withdrawal symptoms that should not be confused with continuing CHS, as noted in the study 1. The most critical aspect of managing CHS is complete cessation of cannabis use, as this is the only definitive treatment for the condition, and all other treatments are focused on symptom management, as emphasized in the most recent study 1.

From the Research

Definition and Characteristics of Cannabinoid Hyperemesis Syndrome (CHS)

• Cannabinoid hyperemesis syndrome (CHS) is a syndrome of cyclic vomiting associated with cannabis use 2.
• The syndrome is characterized by symptoms of cyclic abdominal pain, nausea, and vomiting in the setting of prolonged cannabis use 3, 4.
• CHS is frequently unrecognized by clinicians, leading to extensive and unnecessary testing and treatment 4.

Diagnostic Characteristics

• History of regular cannabis use for any duration of time (100%) 2.
• Cyclic nausea and vomiting (100%) 2.
• Resolution of symptoms after stopping cannabis (96.8%) 2.
• Compulsive hot baths with symptom relief (92.3%) 2.
• Male predominance (72.9%) 2.
• Abdominal pain (85.1%) 2.
• At least weekly cannabis use (97.4%) 2.

Pathophysiology

• The pathophysiology of CHS remains unclear with a dearth of research dedicated to investigating its underlying mechanism 2.
• Prolonged high doses of the main psychotropic compound in cannabis, Δ9-tetrahydrocannabinol (THC), result in changes to the endocannabinoid system by acting on the cannabinoid 1 (CB1) receptor, which may cause CHS 5.
• The endocannabinoid system changes can dysregulate stress and anxiety responses, thermoregulation, the transient receptor potential vanilloid system, and several neurotransmitters systems, and are thus potential candidates for mediating the pathophysiology of CHS 5.

Treatment Options

• Supportive care with intravenous fluids, dopamine antagonists, topical capsaicin cream, and avoidance of narcotic medications has shown some benefit in the acute setting 2.
• Topical capsaicin is a proposed treatment for CHS; it binds TRPV1 with high specificity, impairing substance P signaling in the area postrema and nucleus tractus solitarius via overstimulation of TRPV1 3.
• Antipsychotics (such as haloperidol), benzodiazepines, and/or capsaicin cream appear to be the most efficacious in the treatment of this unique disorder 4.
• Cannabis cessation appears to be the best treatment for CHS 2, 4, 5.