Nizatidine

Pronunciation: ny-ZA-ti-deen.

Generic name
nizatidine
Drug class
Histamine H2-receptor antagonist (H2 blocker)
Form
Capsule (150 mg, 300 mg) or oral solution (15 mg/mL)
Route
Oral
Legal status
Prescription-only (generic capsules/oral solution)

Availability and supply rules vary by country

Trade names by country: United States · United Kingdom · Canada · Australia · New Zealand

Australia: NIZATIDINE-RJIC (and other current ARTG-registered nizatidine brands) (7) · Full directory

What nizatidine is and how it works

Nizatidine is a prescription H2-receptor antagonist that reduces the amount of acid the stomach makes. It is used to treat and help prevent duodenal and gastric ulcers and to treat gastroesophageal reflux disease (GERD). (1) (4)

Take nizatidine exactly as your prescriber directs. Your dose depends on your condition and kidney function -- it is not the same fixed dose for everyone, and people with reduced kidney function usually need a lower dose.

Mechanism of action: how nizatidine works

Nizatidine is a competitive, reversible H2-receptor antagonist that reduces basal and stimulated gastric acid secretion and pepsin concentration, without significant inhibition of cytochrome P450 enzymes. (1) (4)

What nizatidine is used for

Duodenal and gastric ulcer

Used to treat active duodenal ulcers and active benign gastric ulcers, and as maintenance treatment to help prevent duodenal ulcers from coming back once healed. (1) (4)

Gastroesophageal reflux disease (GERD)

Used to treat GERD, including esophagitis (inflammation of the esophagus) with erosions or ulcers and associated heartburn. (1) (4)

NSAID-associated ulcers

In the UK label, also used for ulcers associated with non-steroidal anti-inflammatory drug (NSAID) use. (4)

Before taking nizatidine

Do not take / not appropriate for

  • Do not take nizatidine if you have had a serious allergic reaction to it or to any other H2-receptor antagonist medicine (such as famotidine, ranitidine, or cimetidine) -- cross-sensitivity within this class has been reported. (all countries) (1) (4)

Tell your clinician about

  • Any kidney problems -- your dose needs to be reduced if your kidney function is moderately or severely reduced.
  • Any liver problems.
  • Any new or worsening stomach symptoms, unexplained weight loss, or difficulty swallowing, since feeling better on nizatidine does not rule out a more serious stomach condition and should be checked by a clinician.
  • All other medicines you take.
  • Pregnancy, plans for pregnancy, or breastfeeding.
(1) (4)

How to take nizatidine

  • Take exactly as your prescriber directs, usually once daily at bedtime or twice daily depending on the condition being treated.
  • Swallow capsules whole; if using the oral solution, use the measuring device provided.
  • Continue for the full length of time your prescriber recommends, even if you feel better, since ulcer healing takes several weeks.
(1) (4)

Procedures and treatment changes

Tell the treating team before surgery, procedures, or any medicine change. Do not alter treatment without the responsible clinician. (1) (2) (3) (4) (5) (6) (7) (8)

Missed dose

If you miss a dose, contact your prescriber or pharmacist for guidance specific to your regimen rather than doubling a later dose.

Overdose

Seek urgent medical attention or contact a poison control/information service if you think too much nizatidine has been taken. (1)

Side effects

Side effects and their urgency vary; report severe, persistent, or concerning symptoms.

Headache -- the most commonly reported side effect.

What to notice: Headache -- the most commonly reported side effect.

What to do: Discuss persistent or troublesome symptoms with the treating clinician or pharmacist. (1)

Rhinitis (runny/stuffy nose), diarrhoea, abdominal pain, nausea, flatulence, dizziness, and vomiting.

What to notice: Rhinitis (runny/stuffy nose), diarrhoea, abdominal pain, nausea, flatulence, dizziness, and vomiting.

What to do: Discuss persistent or troublesome symptoms with the treating clinician or pharmacist. (1)

Sweating and skin urticaria (hives), reported more often than with placebo.

What to notice: Sweating and skin urticaria (hives), reported more often than with placebo.

What to do: Discuss persistent or troublesome symptoms with the treating clinician or pharmacist. (4)

Sleepiness (somnolence).

What to notice: Sleepiness (somnolence).

What to do: Discuss persistent or troublesome symptoms with the treating clinician or pharmacist. (4)

Serious warnings

Signs of a serious allergic reaction (anaphylaxis) — emergency

Symptoms: Swelling of the face, lips, tongue, or throat; difficulty breathing; widespread rash or hives.

Action: Seek emergency medical help immediately. (2)

Reversible confusion or mental changes (reported rarely, particularly in older adults or people with reduced kidney function) — high caution

Symptoms: New confusion, disorientation, agitation, or unusual drowsiness.

Action: Contact your prescriber promptly if this occurs -- your prescriber will assess whether the dose needs adjusting; this has been reported to be reversible when addressed under medical care. (2)

Signs of liver problems (rare) — high caution

Symptoms: Yellowing of the skin or eyes (jaundice), dark urine, unusual tiredness, or right-upper abdominal pain.

Action: Contact your prescriber promptly -- rare reversible liver enzyme elevation and hepatitis have been reported. (1) (2)

Persistent or worsening stomach symptoms, unexplained weight loss, or difficulty swallowing — high caution

Symptoms: Ongoing stomach pain, unintentional weight loss, difficulty or pain swallowing, or vomiting blood.

Action: Tell your prescriber -- feeling better on nizatidine does not rule out a more serious underlying stomach condition, which needs separate clinical evaluation. (1) (4)

Interactions

  • No clinically significant interaction has been found with theophylline, warfarin, benzodiazepines (e.g. diazepam), phenytoin, or metoprolol in the studies reviewed, and nizatidine does not inhibit the cytochrome P450 liver enzyme system. (1) (4)
  • Tell your prescriber about all other medicines you take, since individual interaction risk should always be checked case by case. (1)

Pregnancy, breastfeeding, kidney/liver function, age

Pregnancy

Animal studies did not show harm to the fetus, but there are no adequate, well-controlled studies in pregnant women. Discuss the benefits and risks with your prescriber. (1) (2) (3) (4) (5) (6) (7) (8)

Breastfeeding

A small amount (about 0.1% of the dose) passes into breast milk. Discuss whether to continue breastfeeding with your prescriber. (1) (2) (3) (4) (5) (6) (7) (8)

Children

Not established as a general use in the sources reviewed for this dossier; use in children should be directed by a paediatric prescriber. (1) (2) (3) (4) (5) (6) (7) (8)

Elderly

No separate dose adjustment based on age alone is described beyond the general renal-impairment adjustment, but older adults are more likely to have reduced kidney function and should be monitored accordingly; rare confusion has been reported particularly in this group. (1) (2) (3) (4) (5) (6) (7) (8)

Hepatic_impairment

Use with caution; rare hepatocellular injury and elevated liver enzymes have been reported, generally reversible. (1) (2) (3) (4) (5) (6) (7) (8)

Renal_impairment

Dose must be reduced for creatinine clearance below 50 mL/min, since nizatidine is principally excreted by the kidneys. (1) (2) (3) (4) (5) (6) (7) (8)

Monitoring

Before starting

  • Assessment for alarm symptoms that may indicate gastric malignancy rather than simple ulcer/GERD
  • Kidney function (creatinine clearance) to determine correct dose
  • Liver function where relevant

During treatment

  • Watching for resolution of ulcer/GERD symptoms and reporting any new or worsening symptoms.
  • Kidney and liver function monitoring where clinically indicated.
  • Endoscopic confirmation of healing where clinically appropriate, since symptom improvement alone does not exclude malignancy.
(1) (4)

Storage

Store at 20-25C (68-77F) in a tight, light-resistant container (US label); UK label specifies storage below 25C. Keep out of reach of children.

Study the drug class: H2-receptor antagonists

Professional information

Clinician-facing context only, sourced from the current US FDA prescribing information and UK SmPC; verify against the current full label before prescribing.

United States

Indication: Duodenal ulcer, GERD, benign gastric ulcer

Dose summary: 300 mg once daily at bedtime or 150 mg twice daily (duodenal ulcer, up to 8 weeks); 150 mg once daily at bedtime (maintenance); 150 mg twice daily (GERD, up to 12 weeks); 300 mg daily or 150 mg twice daily (benign gastric ulcer, up to 8 weeks). Renal adjustment: CrCl 20-50 mL/min -> 150 mg daily (or every other day for maintenance); CrCl <20 mL/min -> 150 mg every other day (or every 3 days for maintenance).

Renal context: Dose reduction required per the schedule above; nizatidine is principally excreted renally. (1)

United Kingdom

Indication: Duodenal ulcer, gastric ulcer, GERD, NSAID-associated ulcers

Dose summary: 300 mg evening for 4 weeks (duodenal ulcer, or 150 mg twice daily); 300 mg evening for 4-8 weeks (gastric ulcer); 150 mg evening (prophylaxis); 150-300 mg twice daily up to 12 weeks (GERD); 300 mg daily up to 8 weeks (NSAID-associated ulcers).

Renal context: CrCl <50 mL/min: reduce to 150 mg evening or alternate-day dosing depending on indication and severity. (4)

Mechanism of action

Hepatic guidance

Rare hepatocellular injury and transient liver enzyme elevation reported; generally reversible on discontinuation, which should be a clinician-directed decision.

Overdose note

Limited overdose data; general supportive management and monitoring, guided by a poison-information service or emergency clinician. (1) (4)

Frequently asked questions

Is nizatidine currently available in the US, UK, Europe, Canada, Australia, and New Zealand?

Generic nizatidine remains currently authorised and marketed in the United States, United Kingdom, Canada, and Australia. In the European Union, the French national brand Nizaxid was discontinued by its manufacturer in 2020, and nizatidine has not been currently marketed in New Zealand since at least 2000 per regulator committee records -- these two markets are shown as previously authorised, not currently available. (1) (4) (5) (6) (7) (8)

Did nizatidine have any contamination recalls?

Yes. In 2020, the FDA identified NDMA (a probable human carcinogen at high exposure) above acceptable limits in specific nizatidine lots/products from certain manufacturers, leading to voluntary recalls -- similar to the separate ranitidine (Zantac) NDMA issue the same year. These were product- and lot-specific recalls, not a removal of nizatidine as an active ingredient from the market; generic nizatidine remains available from other manufacturers today. (3)

Can I stop taking nizatidine on my own if I feel better?

Discuss any change in how long you take nizatidine with your prescriber. Feeling better does not always mean an ulcer has fully healed, and stopping early without checking with your prescriber could leave the underlying condition untreated. (1) (4)

What is the mechanism of action of nizatidine?

Nizatidine is a competitive, reversible H2-receptor antagonist that reduces basal and stimulated gastric acid secretion and pepsin concentration, without significant inhibition of cytochrome P450 enzymes. (1) (4)

What is the generic name of Nizatidine?

The generic name is nizatidine. (1) (4)

What class of drug is nizatidine?

Nizatidine is classed as: Histamine H2-receptor antagonist (H2 blocker). (1) (4)

References

  1. NIZATIDINE capsule -- full prescribing informationU.S. Food and Drug Administration / DailyMed (NIH), full prescribing information, Actavis Pharma, Inc. · United States · dated 2022-06-30 · accessed 2026-07-30 · source 1
  2. NIZATIDINE oral solution -- full prescribing informationU.S. Food and Drug Administration / DailyMed (NIH), full prescribing information, Amneal Pharmaceuticals LLC · United States · dated 2024-10-23 · accessed 2026-07-30 · source 2
  3. Amneal Pharmaceuticals, LLC. Issues Voluntary Nationwide Recall of Nizatidine Oral Solution, 15 mg/mL, Due to Potential Levels of NDMA Impurity Amounts Above the Levels Established by FDAU.S. Food and Drug Administration -- recalls/market withdrawals/safety alerts · United States · dated 2020 · accessed 2026-07-30 · source 3
  4. Nizatidine 150 mg Capsules, Hard -- Summary of Product Characteristicselectronic medicines compendium (emc), United Kingdom -- Viatris (formerly Mylan/Upjohn) · United Kingdom · accessed 2026-07-30 · source 4
  5. NIZAXID (nizatidine) -- Haute Autorite de Sante recordHaute Autorite de Sante (HAS), France -- national transparency-commission record for Nizaxid (nizatidine), Norgine Pharma · European Union (France, national authorisation -- nizatidine has no EMA centralised marketing authorisation) · dated 2019-06-12 · accessed 2026-07-30 · source 5
  6. pms-NIZATIDINE -- Health Canada Drug Product Database listing and product monographHealth Canada -- Drug and Health Products Portal (Drug Product Database) and product monograph, Pharmascience Inc. · Canada · dated 2021-09-16 · accessed 2026-07-30 · source 6
  7. NIZATIDINE-RJIC nizatidine 150mg capsule blister pack -- ARTG registrationTherapeutic Goods Administration (TGA), Australia · Australia · dated 2024-01-30 · accessed 2026-07-30 · source 7
  8. Medicines Classification Committee, 23rd Meeting Minutes (May 2000) -- H2-receptor antagonist reclassification discussionMedsafe (New Zealand regulator) -- Medicines Classification Committee minutes · New Zealand · dated 2000-05 · accessed 2026-07-30 · source 8

Brand names by country

Single-ingredient nizatidine names are shown separately by country. Product availability, strengths, and supply rules can change; combination products are not included here.

Priority countries

United States

  • Nizatidine (generic) (1) (2)FDA ANDA currently marketed · 150 mg, 300 mg capsules, 15 mg/mL oral solution · Actavis Pharma, Inc. / Amneal Pharmaceuticals LLC (generic manufacturers)

United Kingdom

  • Nizatidine (generic) (4)MHRA licensed emc smpc confirmed · 150 mg, 300 mg · Viatris

Canada

  • AXID

Australia

  • NIZATIDINE-RJIC (and other current ARTG-registered nizatidine brands) (7)TGA ARTG registered 2024-01-30 confirmed · 150 mg · Arrotex Pharmaceuticals Pty Ltd

New Zealand

  • Nizatidine (no current Medsafe data sheet or CMI) (8)no longer marketed per 2000 MCC minutes no current datasheet · not applicable -- not currently marketed · not applicable
View brands in additional countries.

European Union

Nizaxid (France, national authorisation -- no EMA centralised approval exists for nizatidine) (5)

This page provides general reference information about nizatidine and is not a substitute for advice from the prescriber managing your treatment. All dosing and treatment decisions should be made with your prescriber.

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