![]() ![]() The detailed phasic nature of cannabinoid hyperemesis syndrome is similar to that described for CVS, but often it is accompanied with compulsive hot bathing (or hot showers) which seems to temporary relieve patients’ symptoms. The phenomenon is now referred to as cannabis hyperemesis syndrome, which manifests with recurrent intense nausea, intractable vomiting and abdominal pain. The seemingly rare cannabinoid hyperemesis was originally reported from Australia in 2004 but appears to be potentially much more common, as evidenced by the cited recent reports, each discussing one or several cases from the Netherlands, New Zealand, Spain, England and the USA. Co-existing conditions in adults with CVS include migraine headaches, psychiatric disease, gastroesophgeal reflux disease, irritable bowel syndrome, gallbladder disease, insulin-dependent diabetes mellitus and chronic marijuana use. Triggers of acute episodes of CVS include infections, psychological stress, motion sickness, lack of sleep, physical exhaustion and certain foods. The accompanying signs include anorexia, retching, increased salivation, abdominal pain, headache, pallor, listlessness, photophobia and phonophobia. The clinical feature of CVS can be divided into four phases: (i) the interepisodic “well phase” that persists from weeks to months between vomiting episodes when the patient is relatively symptom free (ii) the “prodromal nauseous phase” of varying intensity that encompasses the time when the patient begins to sense the approach of vomiting and can last from minutes to hours (iii) the “emetic phase” is characterized by intense, persistent nausea with repeated episodes of vomiting which may persist from hours to 10 days, and (iv) the “recovery phase”, begins with termination of vomiting, and ends with hunger and tolerance of oral intake. Affected patients exhibit a stereotypical pattern of multiple episodes of vomiting with frequent visits to emergency departments for relief of nausea, vomiting and dehydration. While CVS has been mainly studied in pediatric patients, this enigmatic syndrome represents a continuum affecting all ages, including young and middle aged adults. CVS is a disorder characterized by recurrent, self-limited episodes of severe nausea and vomiting interspersed with symptom free periods. The association of chronic cannabis use with cyclic-type vomiting syndrome (CVS) in adults is an obscure phenomenon which has recently been recognized by clinicians following publication of a number of case reports as well as three clinical series. In addition, human and animal findings suggest that chronic exposure to cannabis may not be a prerequisite for the induction of vomiting but is required for the intensity of emesis. These encompass: (1) pharmacokinetic factors such as long half-life, chronic exposure, lipid solubility, individual variation in metabolism/excretion leading to accumulation of emetogenic cannabinoid metabolites, and/or cannabinoid withdrawal and (2) pharmacodynamic factors including switching of the efficacy of Δ 9-THC from partial agonist to antagonist, differential interaction of Δ 9-THC with Gs and Gi signal transduction proteins, CB 1 receptor desensitization or downregulation, alterations in tissue concentrations of endocannabinoid agonists/inverse agonists, Δ 9-THC-induced mobilization of emetogenic metabolites of the arachidonic acid cascade, brainstem versus enteric actions of Δ 9-THC, and/or hypothermic versus hyperthermic actions of Δ 9-THC. Although some traditional hypotheses have already been proposed, the present review critically explores the basic science of these explanations in the clinical setting and provides more current mechanisms for the induced hyperemesis. The syndrome appears to be a paradox and the pathophysiological mechanism(s) underlying the induced vomiting remains unknown. Although considered rare, recent international publications of numerous case reports suggest the contrary. It is characterized by repeated cyclical vomiting and learned compulsive hot water bathing behavior. ![]() Cannabis-induced hyperemesis is a recently recognized syndrome associated with chronic cannabis use. ![]() Cannabinoids prevent vomiting by inhibition of release of emetic neurotransmitters via stimulation of presynaptic cannabinoid CB 1 receptors. Cannabinoids are used clinically on a subacute basis as prophylactic agonist antiemetics for the prevention of nausea and vomiting caused by chemotherapeutics. ![]()
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