What medication can be used to treat hyperemesis (excessive vomiting) cannabis syndrome that is unresponsive to Reglan (metoclopramide)?

Treatment for Cannabinoid Hyperemesis Syndrome Unresponsive to Metoclopramide

Haloperidol (0.5-2 mg IV or PO every 4-6 hours) is the most effective first-line pharmacological treatment for cannabinoid hyperemesis syndrome (CHS) that has not responded to metoclopramide. 1

First-Line Treatment Options

When metoclopramide (Reglan) has failed to control symptoms in CHS, consider:

1. Dopamine receptor antagonists:

   • Haloperidol 0.5-2 mg IV or PO every 4-6 hours 1
   • Monitor for extrapyramidal side effects

2. Topical capsaicin cream (0.1%):

   • Apply to the abdomen for symptomatic relief 1
   • Works by activating TRPV1 receptors, which may help regulate the endocannabinoid system

3. Benzodiazepines:

   • Lorazepam 0.5-2 mg PO/SL/IV every 6 hours 1, 2
   • May be particularly effective due to its action on reducing CB1 receptor activation in the frontal cortex 2

Second-Line Treatment Options

If first-line treatments fail to provide relief:

• Olanzapine: 5-10 mg PO daily 1
• Corticosteroids: For short-term use in severe cases 1
• Antiepileptics: Zonisamide and levetiracetam have shown some efficacy 3

Supportive Measures

• IV fluid rehydration: Essential for correcting dehydration 1
• Hot showers/baths: Consistently reported as providing temporary relief 1, 3
• Quiet, supportive environment: Minimize stimulation during acute episodes 1

Treatment Algorithm

1. Start with haloperidol 0.5-2 mg IV/PO AND topical capsaicin
2. If inadequate response within 1-2 hours, add lorazepam 0.5-2 mg
3. Ensure adequate hydration with IV fluids
4. For persistent symptoms, consider olanzapine or corticosteroids
5. Emphasize the importance of cannabis cessation as the definitive treatment

Important Considerations

• Avoid opioids: They can worsen nausea and have high addiction potential in this population 1
• Limited efficacy of traditional antiemetics: Standard antiemetics like ondansetron may provide only minimal benefit 1, 3
• Definitive treatment: Complete cannabis cessation for at least 3-6 months is necessary for full resolution 1

Special Populations

For adolescents with CHS, a combination of haloperidol (5 mg IV) with either lorazepam (2 mg IV) or topical capsaicin (0.025%) has shown effectiveness 4.

Common Pitfalls

• Misdiagnosis: CHS is often misdiagnosed, leading to unnecessary testing and ineffective treatments. Look for the triad of chronic cannabis use, cyclic vomiting, and relief with hot showers 1
• Relying on conventional antiemetics: Traditional antiemetics often fail in CHS 5
• Failure to address cannabis use: Without addressing the underlying cause through cannabis cessation, symptoms will likely recur 1

Remember that while pharmacological interventions can provide symptomatic relief during acute episodes, complete resolution of CHS requires cannabis cessation, which should be emphasized as part of the treatment plan.