Is Tetrahydrocannabinol (THC) causing nausea?

From the Guidelines

THC, the main psychoactive compound in cannabis, can cause nausea rather than relieve it, and the most effective way to manage this is to stop or reduce cannabis consumption immediately. This paradoxical effect, known as cannabinoid hyperemesis syndrome (CHS) in severe cases, occurs because while THC initially activates anti-nausea receptors in the brain, prolonged or high-dose use can overstimulate these receptors, causing the opposite effect 1.

Key Points to Consider

• Individual tolerance varies significantly, with new users and those consuming high-potency products being more susceptible to THC-induced nausea 1.
• For immediate relief, try taking small sips of water, breathing fresh air, and resting in a comfortable position.
• Over-the-counter medications like dimenhydrinate (Dramamine) 50mg or ginger supplements (250mg) can help manage symptoms, but it is essential to note that opioids should be avoided due to worsening of nausea and high risk of addiction 1.
• Some people find that using products with balanced THC:CBD ratios or lower THC concentrations helps prevent this side effect.
• If nausea persists or is accompanied by severe vomiting, seek medical attention as dehydration can become a serious concern.

Management and Treatment

• The clinical approach in the emergency department (ED) requires immediate evaluation for life-threatening disorders, such as acute abdomen, bowel obstruction, mesenteric ischemia, pancreatitis, and myocardial infarction, among others 1.
• For long-term management, counseling to achieve marijuana cessation and tricyclic antidepressants, such as amitriptyline, are the mainstay of therapy, with the minimal effective dose being 75–100 mg at bedtime, starting at 25 mg and titrating the dose with increments each week to reach minimal effective dose 1.
• Topical capsaicin (0.1%) cream is applied with close monitoring of efficacy and adverse effects 1.

From the Research

THC and Nausea

• THC, the primary psychoactive compound in cannabis, has been shown to have both positive and negative effects on nausea, depending on the context and individual response 2, 3, 4, 5, 6.
• On one hand, studies have demonstrated that cannabinoids, including THC, can be effective in reducing nausea and vomiting, particularly in patients undergoing chemotherapy 2.
• On the other hand, chronic cannabis use has been linked to a condition known as cannabis hyperemesis syndrome (CHS), characterized by recurrent episodes of severe nausea and vomiting 3, 4, 6.

Cannabis Hyperemesis Syndrome (CHS)

• CHS is a condition that affects some long-term cannabis users, leading to persistent and severe nausea and vomiting 3, 4, 6.
• The exact mechanisms underlying CHS are not fully understood, but it is thought to be related to the chronic use of cannabinoids, particularly THC 3, 6.
• Treatment options for CHS include cannabis cessation, hot water hydrotherapy, topical capsaicin cream, and various medications such as haloperidol, droperidol, and aprepitant 4, 6.

Effectiveness of Cannabis Products for Nausea Relief

• A study using the Releaf App found that 96.4% of participants experienced symptom relief from nausea after using cannabis products, with an average reduction in symptom intensity of -3.85 points on a 0-10 visual analog scale 5.
• The study also found that flower and concentrates were the most effective products for nausea relief, while products labeled as Cannabis indica underperformed those labeled as Cannabis sativa or hybrid 5.
• Higher THC and lower CBD content were associated with greater symptom relief in sessions using flower products 5.