What Is Nizatidine? Uses, Dosage, and What You Need to Know in 2026

Nizatidine is a prescription medication that reduces the amount of acid your stomach produces. It belongs to a class of drugs called H2 blockers (histamine H2-receptor antagonists) and is used to treat conditions caused by excess stomach acid — including peptic ulcers, GERD, and heartburn. Originally marketed as Axid by Eli Lilly, the brand has been discontinued; generic nizatidine is the only form available today.

What Is Nizatidine Used For?

Nizatidine is FDA-approved for the following conditions:

Active duodenal ulcer: Short-term treatment of active ulcers in the upper small intestine (duodenum); most heal within 4 weeks

Maintenance of healed duodenal ulcer: Long-term therapy (up to 1 year) to prevent duodenal ulcers from coming back after healing

Active benign gastric ulcer: Short-term treatment of stomach ulcers (gastric ulcers), up to 12 weeks

Gastroesophageal reflux disease (GERD): Treatment of heartburn and symptoms of GERD, where stomach acid backs up into the esophagus

Erosive and ulcerative esophagitis: Treatment of acid-related damage to the esophagus, up to 12 weeks

Nizatidine Dosage: How Much Do You Take?

Nizatidine comes as 150 mg and 300 mg capsules. The dose depends on what you're being treated for:

Active duodenal ulcer (treatment): 300 mg once daily at bedtime, OR 150 mg twice daily — up to 8 weeks

Duodenal ulcer maintenance: 150 mg once daily at bedtime — up to 1 year

Active benign gastric ulcer: 300 mg once daily at bedtime OR 150 mg twice daily — up to 12 weeks

GERD / erosive esophagitis: 150 mg twice daily — up to 12 weeks

Always follow your doctor's specific dosing instructions, which may differ from these standard doses depending on your condition and kidney function.

How to Take Nizatidine

Nizatidine capsules can be taken with or without food. If you're taking it once daily, take it at bedtime — this is when the medication works best to reduce nighttime stomach acid secretion. If you're taking it twice daily, take one dose in the morning and one in the evening.

If the medication upsets your stomach, try taking it with a small amount of food. Take it with a full glass of water. Swallow capsules whole — do not crush or open them unless directed by your pharmacist.

How Long Does Nizatidine Take to Work?

Nizatidine starts reducing stomach acid quickly — typically within 30 minutes to 1 hour after taking it. Most patients notice symptom relief within the first few days of treatment. For ulcer healing, most duodenal ulcers heal within 4 weeks of treatment, though a full 8-week course may be needed in some cases.

Is Nizatidine the Same as Axid?

Yes — Axid and Axid AR were brand names for nizatidine, originally made by Eli Lilly. The brand was discontinued; only generic nizatidine capsules are available today. Generic nizatidine contains the same active ingredient and is therapeutically equivalent to Axid. Multiple manufacturers produce it, including Glenmark, Amneal, Apotex, and Teva.

Is Nizatidine a Controlled Substance?

No. Nizatidine is not a controlled substance. It is a Schedule-free prescription medication with no DEA scheduling. This means it can be prescribed and refilled like any other regular prescription drug, with no special DEA requirements or limits on refills beyond what your doctor specifies.

Want to understand exactly how nizatidine reduces acid? Read our plain-English explanation: How Does Nizatidine Work? Mechanism of Action Explained.

If you've got your prescription and need to find nizatidine at a pharmacy near you, medfinder can locate it for you.