How to manage a 15-year-old female with recurrent morning vomiting, abdominal colic, and nausea, with a history of anxiety and reflux?

Management of Recurrent Morning Vomiting in an Adolescent Female

This 15-year-old female with stereotypical morning vomiting episodes, abdominal colic that improves after vomiting, and a history of anxiety should be evaluated for cyclic vomiting syndrome (CVS), and initial management should include obtaining urinalysis, complete metabolic panel, and cannabis use screening, followed by initiation of prophylactic therapy if CVS is confirmed. 1, 2

Immediate Diagnostic Evaluation

Essential Laboratory Testing

• Obtain complete blood count, serum electrolytes, glucose, liver function tests, and urinalysis to exclude metabolic causes and assess hydration status 2
• Test for hypercalcemia, thyroid function, and consider cortisol levels if clinically indicated, as metabolic abnormalities can present with recurrent vomiting 2
• Cannabis use screening is critical in this age group—Cannabis Hyperemesis Syndrome (CHS) must be excluded given the high prevalence in adolescents and similar presentation to CVS 2

Pattern Recognition for CVS

• The stereotypical pattern of morning vomiting occurring 30 minutes post-breakfast, associated with abdominal pain that improves after vomiting, and nausea throughout the day strongly suggests CVS 1
• CVS is characterized by at least 3 discrete episodes in a year (with 2 in the prior 6 months), each lasting less than 7 days, separated by symptom-free periods 1
• The presence of anxiety disorder is a supportive feature, as psychological comorbidities are common in CVS patients 3
• Abdominal pain during episodes does not exclude CVS—it is present in most patients and should not redirect the diagnosis 1

Structural Evaluation

Imaging Considerations

• Perform one-time upper GI imaging or esophagogastroduodenoscopy (EGD) to exclude obstructive lesions, particularly given the recent discontinuation of reflux medications 2
• Avoid repeated endoscopy or imaging studies unless new symptoms develop 2
• Upper endoscopy with esophageal biopsy may be useful to exclude eosinophilic esophagitis and assess for esophageal inflammation from prior reflux 1

Critical Differential Diagnosis Considerations

Cannabis Hyperemesis Syndrome

• If heavy cannabis use is identified, CHS requires 6 months of cannabis cessation or at least 3 typical cycle lengths without vomiting for definitive diagnosis 2
• Do not stigmatize patients with cannabis use—offer abortive and prophylactic therapy even with ongoing use, as treatments can still be effective 2

Medication-Related Causes

• The recent discontinuation of reflux medications may be relevant—consider whether stopping these medications coincided with symptom onset 4, 5
• Review all current medications (anxiety medications) for potential adverse effects causing nausea and vomiting 4, 5

Pharmacologic Management Algorithm

Initial Antiemetic Therapy

• Initiate dopamine receptor antagonists titrated to maximum benefit and tolerance, such as metoclopramide (10 mg), prochlorperazine, or haloperidol 2, 6
• Monitor for extrapyramidal symptoms with dopamine antagonists, particularly in young patients 2, 6
• Metoclopramide carries a black box warning for tardive dyskinesia with prolonged use 6

Second-Line Therapy

• If symptoms persist after 4 weeks of dopamine antagonist therapy, add a 5-HT3 antagonist such as ondansetron 8 mg 2, 6
• Monitor for QTc prolongation when using ondansetron, especially in combination with other QT-prolonging agents 2
• Administer around-the-clock rather than PRN dosing for persistent symptoms 6

Route of Administration

• During active vomiting episodes, avoid oral route—use IV, IM, sublingual, or rectal routes 6
• Sublingual ondansetron may have superior absorption compared to oral tablets in vomiting patients 6

Prophylactic Management for CVS

Tricyclic Antidepressants

• High-dose tricyclic antidepressants show impressive and sustained response in CVS, with up to 85% of patients responding 3
• This is particularly appropriate given the patient's anxiety disorder, as psychological comorbidities predict poorer response to standard antiemetics 3

Abortive Therapy Education

• Patient education on recognizing the prodromal phase is imperative—earlier intervention during this phase is associated with higher probability of successfully aborting an episode 1
• "Rehearse" with the patient the actions to take at the first sign of prodromal symptoms 1

Supportive Care Measures

Hydration and Nutrition

• Ensure adequate fluid intake of at least 1.5 L/day 2
• Recommend small, frequent meals rather than large meals 2
• Provide thiamin supplementation to prevent Wernicke's encephalopathy in patients with persistent vomiting 2

Electrolyte Management

• Prolonged vomiting can cause hypokalemia, hypochloremia, and metabolic alkalosis—address electrolyte imbalances, particularly hypokalemia and hypomagnesemia 2

Critical Pitfalls to Avoid

• Never use antiemetics if mechanical bowel obstruction is suspected, as this can mask progressive ileus and gastric distension 2, 6
• Do not pursue repeated endoscopy or imaging unless new symptoms develop 2
• Avoid dismissing abdominal pain as inconsistent with CVS—it is present in most patients 1
• Do not overlook cannabis use screening in this age group 2
• If reflux was the original diagnosis, consider whether milk protein allergy could have been the underlying cause, as it can mimic GERD 1

Consideration of Reflux Recurrence

If GERD is Contributing

• If gastroparesis or gastritis is suspected after evaluation, consider restarting a proton pump inhibitor (omeprazole 20 mg once daily before meals) and continue metoclopramide as it promotes gastric emptying 2, 7
• Omeprazole is dosed at 20 mg once daily for adolescents weighing 20 kg or greater for treatment of symptomatic GERD, for up to 4 weeks 7
• Take omeprazole before meals; antacids may be used concomitantly 7