From the Guidelines
No, a patient should not take Compazine (prochlorperazine), Zofran (ondansetron), and Reglan (metoclopramide) simultaneously. These medications are all antiemetics that work through different mechanisms, and taking them together increases the risk of side effects, particularly extrapyramidal symptoms (movement disorders) which are more common with Compazine and Reglan 1.
Key Considerations
- Both Compazine and Reglan are dopamine antagonists, and using them together creates redundancy and heightened risk without additional benefit.
- Zofran works differently by blocking serotonin receptors, but combining all three provides no therapeutic advantage over using just one appropriate agent.
- This combination could increase the risk of QT interval prolongation (a heart rhythm abnormality), especially with Zofran.
Alternative Approach
- Patients should use one antiemetic as prescribed by their healthcare provider, and if it's ineffective, discuss switching to an alternative rather than adding multiple agents simultaneously.
- The NCCN guidelines suggest adding one agent from a different drug class to the current regimen for breakthrough treatment of chemotherapy-induced nausea/vomiting, rather than combining multiple agents from the same class 1.
Relevant Medications and Dosages
- Olanzapine 5–10 mg PO daily (category 1) is recommended for breakthrough treatment, as an atypical antipsychotic 1.
- Other options include lorazepam, dronabinol, nabilone, haloperidol, metoclopramide, scopolamine, and phenothiazines like prochlorperazine and promethazine, as well as 5-HT3 RAs like dolasetron, granisetron, and ondansetron, and steroids like dexamethasone 1.
From the Research
Medication Interactions
- The question of whether a patient can take Conpazine (prochlorperazine), Zofran (ondansetron), and Reglan (metoclopramide) at the same time is complex and requires careful consideration of potential interactions and side effects.
- Studies have compared the efficacy of these medications in preventing nausea and vomiting, but none have specifically addressed the safety of taking all three simultaneously 2, 3, 4, 5, 6.
Efficacy of Individual Medications
- Ondansetron has been shown to be more effective than metoclopramide in preventing nausea and vomiting in patients receiving chemotherapy 2, 3.
- Prochlorperazine has been found to be effective in treating nausea and vomiting, and may be as effective as ondansetron in some cases 4, 6.
- Metoclopramide has been used in combination with other medications to prevent delayed chemotherapy-induced nausea and vomiting, and has been shown to be noninferior to dexamethasone in some studies 5.
Potential Interactions and Side Effects
- Taking multiple antiemetic medications at the same time may increase the risk of side effects, such as sedation, headache, and extrapyramidal symptoms 3, 6.
- The combination of prochlorperazine and metoclopramide may increase the risk of extrapyramidal symptoms, such as akathisia and dystonia 6.
- Ondansetron has been associated with headache and constipation, while metoclopramide has been associated with diarrhea and extrapyramidal symptoms 2, 3, 5.