Alternatives to Metoclopramide If You Can't Fill Your Prescription

Metoclopramide (brand name Reglan) has been a go-to treatment for gastroparesis and nausea for decades. But what happens when your pharmacy runs out, or your doctor wants to explore other options? Several alternatives exist — each with its own mechanism, strengths, and limitations. This guide will help you understand your options so you can have an informed conversation with your prescriber.

Important: Never switch medications on your own. All of the alternatives listed below require a prescription and guidance from your healthcare provider.

Why Patients Look for Metoclopramide Alternatives

There are several reasons a patient or prescriber may seek an alternative to metoclopramide:

• The pharmacy is out of stock
• The patient has developed side effects (drowsiness, restlessness, dystonic reactions)
• Long-term use concerns — metoclopramide is approved for only up to 12 weeks due to the risk of tardive dyskinesia
• Drug interactions with other medications the patient takes
• Contraindications such as Parkinson's disease, epilepsy, or pheochromocytoma

Alternatives for Gastroparesis

Gastroparesis — delayed gastric emptying — is one of the main reasons metoclopramide is prescribed. Its prokinetic (stomach-motility-improving) effect is what's being replaced here.

1. Erythromycin (Low-Dose)

Erythromycin, an antibiotic, is also a potent motilin receptor agonist — meaning it stimulates stomach contractions and speeds gastric emptying. At low doses (e.g., 125–250 mg orally before meals), it is used off-label as a prokinetic for gastroparesis. It is generally used short-term because tachyphylaxis (reduced effectiveness) can develop. It is not a controlled substance and is widely available as a generic.

Key consideration: Can cause nausea itself at higher doses. Drug interactions with medications metabolized by CYP3A4 (statins, some antihistamines).

2. Domperidone (Limited US Availability)

Domperidone is a dopamine D2 antagonist with prokinetic and antiemetic properties similar to metoclopramide. It does not cross the blood-brain barrier as readily, which theoretically reduces the risk of central nervous system side effects like tardive dyskinesia. However, domperidone is not FDA-approved in the United States. It can be obtained through an expanded access (compassionate use) program approved by the FDA. Some compounding pharmacies can prepare it under this program with appropriate documentation.

Key consideration: Not easily accessible in the US; requires special authorization. Associated with QTc prolongation.

Alternatives for Nausea and Vomiting

For patients who primarily use metoclopramide as an antiemetic (for nausea from GERD, chemotherapy, or general causes), there are several well-established alternatives.

3. Ondansetron (Zofran)

Ondansetron is a 5-HT3 receptor antagonist and one of the most widely prescribed antiemetics in the United States. It is available as tablets, ODT (dissolving tablets), and IV. It works differently from metoclopramide — blocking serotonin receptors rather than dopamine — and does not have the same tardive dyskinesia risk. It is FDA-approved for chemotherapy-induced and post-operative nausea and vomiting, and is widely used off-label for other types of nausea.

Key consideration: Does not improve gastric motility, so it is not a replacement for gastroparesis specifically. Risk of QTc prolongation at higher doses.

4. Prochlorperazine (Compazine)

Prochlorperazine is a phenothiazine dopamine antagonist used for severe nausea/vomiting and migraines. It has a similar mechanism to metoclopramide. However, as of 2026, prochlorperazine is itself experiencing a national drug shortage in multiple formulations, making it harder to obtain in some areas.

Key consideration: Also carries a risk of extrapyramidal side effects. Injectable and oral tablet forms are both on shortage as of early 2026.

5. Promethazine (Phenergan)

Promethazine is a first-generation antihistamine and phenothiazine used for nausea, vomiting, and allergic reactions. It is more sedating than metoclopramide. It carries a boxed warning against IV administration due to severe tissue injury risk and should not be used in children under 2.

Key consideration: Significant sedation. Not appropriate for patients who need to drive or operate machinery. Like metoclopramide, it also carries extrapyramidal side effect risk.

Side-by-Side Comparison

Here's a quick overview of how metoclopramide compares to its alternatives:

• Metoclopramide: Prokinetic + antiemetic; 12-week limit; TD risk; not controlled
• Erythromycin (low-dose): Prokinetic only; antibiotic with motility benefit; tachyphylaxis risk
• Domperidone: Prokinetic + antiemetic; not FDA-approved; lower CNS side-effect profile
• Ondansetron: Antiemetic only (no prokinetic); low TD risk; widely available
• Prochlorperazine: Antiemetic; similar mechanism; currently on shortage
• Promethazine: Antiemetic; more sedating; IV boxed warning

Before You Switch: Keep Looking for Metoclopramide

If metoclopramide is working well for you, it's worth trying to find it before switching. Use medfinder to check which local pharmacies have it in stock, or read our full guide on how to find metoclopramide near you.