From the Guidelines
For severe vomiting, ondansetron (4-8 mg bid or tid) is a recommended alternative to diphenhydramine, as it has been shown to be effective in improving nausea and vomiting in patients with refractory gastroparesis symptoms 1, 2.
Alternatives to Diphenhydramine
Other options for managing severe vomiting include:
- Granisetron (1 mg bid) or granisetron patch (34.3 mg patch weekly) 1
- Prochlorperazine (5–10 mg qid) or chlorpromazine (10–25 mg tid or qid) 1
- Metoclopramide (5–20 mg tid–qid) to accelerate gastric emptying 1
- Aprepitant (80 mg/day) as a neurokinin (NK-1) receptor antagonist 2 ### Important Considerations When managing severe vomiting, it is essential to:
- Stay hydrated with small sips of clear fluids to prevent dehydration
- Monitor for signs of dehydration, such as excessive thirst, dark urine, or dizziness
- Seek medical attention immediately if vomiting is severe, persistent beyond 24 hours, accompanied by high fever, severe abdominal pain, or signs of dehydration ### Evidence-Based Recommendations The recommended alternatives to diphenhydramine are based on the most recent and highest quality studies, including the AGA clinical practice update on management of medically refractory gastroparesis: expert review 1, 2. These studies provide evidence for the efficacy of ondansetron, granisetron, and other medications in improving nausea and vomiting in patients with refractory gastroparesis symptoms.
From the FDA Drug Label
For the Prevention of Nausea and Vomiting Associated with Emetogenic Cancer Chemotherapy For the Prevention of Postoperative Nausea and Vomiting To Facilitate Small Bowel Intubation To Aid in Radiological Examinations Metoclopramide Injection, USP should be given intramuscularly near the end of surgery. The usual adult dose is 10 mg; however, doses of 20 mg may be used
Alternatives to diphenhydramine for severe vomiting:
- Metoclopramide: can be used for the prevention of nausea and vomiting associated with emetogenic cancer chemotherapy, postoperative nausea and vomiting, and to facilitate small bowel intubation 3.
- Prochlorperazine: can be used for the control of severe nausea and vomiting 4.
Key considerations:
- Metoclopramide and prochlorperazine have different dosing regimens and administration routes, which should be carefully considered when selecting an alternative to diphenhydramine.
- The choice of alternative medication should be based on the individual patient's needs and medical history.
From the Research
Alternatives to Diphenhydramine for Severe Vomiting
- 5-HT3 receptor antagonists, such as ondansetron, granisetron, dolasetron, and tropisetron, are considered effective alternatives for treating severe vomiting 5, 6, 7, 8.
- These agents work by inhibiting the action of serotonin at the 5-HT3 receptor, which is involved in the vomiting reflex 7.
- Ondansetron, in particular, has been shown to be effective in preventing nausea and vomiting associated with chemotherapy, radiation, and surgery 6, 8.
- The choice of 5-HT3 receptor antagonist may depend on individual patient factors, such as the presence of comorbid conditions or the potential for drug interactions 5.
- A multimodal approach using a combination of antiemetic drugs, such as a 5-HT3 receptor antagonist with dexamethasone, may be effective in reducing the incidence of postoperative nausea and vomiting (PONV) 9.