Nizatidine is an H2 blocker that lowers the amount of stomach acid. It's used to treat adults with conditions such as ulcers and heartburn due to gastroesophageal reflux disease (GERD). It comes as an oral capsule that's taken by mouth once or twice a day. The brand name Axid has been discontinued, but it's still available as a generic. It's currently not available over the counter, so you'll need a prescription from a healthcare professional to take this medication. Headache and diarrhea are some potential side effects.
Duodenal ulcer (open sore in the upper small intestine)
Gastric ulcer (open sore in the stomach)
Esophagitis (inflammation of the esophagus) and heartburn due to GERD
Nizatidine is a histamine H2 antagonist, or H2 blocker. It blocks your stomach from releasing acid, which prevents heartburn and helps heal ulcers.
Source:Â DailyMed
Along with its needed effects, a medicine may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.
Check with your doctor as soon as possible if any of the following side effects occur:
Rare
Abdominal pain
back, leg, or stomach pain
bleeding or crusting sores on lips
blistering, burning, redness, scaling, or tenderness of skin
blisters on palms of hands and soles of feet
changes in vision or blurred vision
confusion
coughing or difficulty in swallowing
dark-colored urine
dizziness
fainting
fast, pounding, or irregular heartbeat
fever and/or chills
flu-like symptoms
general feeling of discomfort or illness
inflammation of blood vessels
joint pain
light-colored stools
mood or mental changes, including anxiety, agitation, confusion, hallucinations (seeing, hearing, or feeling things that are not there), mental depression, nervousness, or severe mental illness
muscle cramps or aches
nausea, vomiting, or loss of appetite
peeling or sloughing of skin
red or irritated eyes
shortness of breath
skin rash or itching
slow heartbeat
sores, ulcers, or white spots on lips, in mouth, or on genitals
sudden difficult breathing
swelling of face, lips, mouth, tongue, or eyelids
swelling of hands or feet
swollen or painful glands
tightness in chest
troubled breathing
unusual bleeding or bruising
unusual tiredness or weakness
unusually slow or irregular breathing
yellow eyes or skin
Some side effects may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects. Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:
Less common or rare
decrease in sexual desire
decreased sexual ability (especially in patients with Zollinger-Ellison disease who have received high doses of cimetidine for at least 1 year)
difficult urination
dizziness
drowsiness
dryness of mouth or skin
headache
increased or decreased urination
increased sweating
loss of hair
ringing or buzzing in ears
swelling of breasts or breast soreness in females and males
trouble in sleeping
Not all of the side effects listed above have been reported for each of these medicines, but they have been reported for at least one of them. All of the H2-blockers are similar, so any of the above side effects may occur with any of these medicines.
Other side effects not listed may also occur in some patients. If you notice any other effects, check with your healthcare professional.
Call your doctor for medical advice about side effects. You may report side effects to the FDA at 1-800-FDA-1088.
Typically taken by mouth once or twice a day
Comes in two different strengths
Can treat many conditions related to too much stomach acid
Not as strong as other acid-lowering medications like proton pump inhibitors (PPIs)
Not approved for children
Common side effects include headache and diarrhea
If you're only taking nizatidine once a day, make sure you take it at bedtime. The medication can block nighttime stomach acid for up to 12 hours.
You can take nizatidine with or without food. If the medication upsets your stomach, try taking it with food to help.
Nizatidine is usually used short-term, for a few months to treat an ulcer. But you might need to take it longer to keep the ulcer from coming back. Take the medication as directed by your prescriber.
Headache is a common side effect of nizatidine. Let your prescriber know if headaches become bothersome. They might recommend tips on how to provide relief.
Nizatidine can cause some serious health issues. This risk may be even higher for certain groups. If this worries you, talk to your doctor or pharmacist about other options.
Sometimes heartburn, GERD, and other upset stomach symptoms can be signs of serious stomach problems or cancer. And medications like nizatidine can hide these symptoms. Talk to your prescriber if your stomach symptoms don't completely go away with nizatidine or if your symptoms come back really fast after stopping the medication. You might need to undergo testing to see if you have a more serious problem.
Risk factors: Older adults | History of kidney problems
Your body gets rid of nizatidine through your urine. If you have kidney problems, you might have a buildup of medication, which can lead to more side effects. This is especially true for people who're older adults with poor kidney function. Your prescriber might want to monitor your kidney labs to make sure you're taking the appropriate dose of this medication.
Duodenal (small intestine) ulcer: The typical dose is 300 mg by mouth once a day at bedtime OR 150 mg twice a day. After the ulcer has healed, the dose usually goes down to 150 mg once a day at bedtime.
Gastric (stomach) ulcer: The typical dose is 300 mg by mouth once a day at bedtime OR 150 mg twice a day.
Esophagitis and heartburn due to GERD: The typical dose is 150 mg by mouth twice a day.
Your dose might be different if you have kidney problems.
Although certain medicines should not be used together at all, in other cases two different medicines may be used together even if an interaction might occur. In these cases, your doctor may want to change the dose, or other precautions may be necessary. When you are taking any of these medicines, it is especially important that your healthcare professional know if you are taking any of the medicines listed below. The following interactions have been selected on the basis of their potential significance and are not necessarily all-inclusive.
Using medicines in this class with any of the following medicines is not recommended. Your doctor may decide not to treat you with a medication in this class or change some of the other medicines you take.
Using medicines in this class with any of the following medicines is usually not recommended, but may be required in some cases. If both medicines are prescribed together, your doctor may change the dose or how often you use one or both of the medicines.
Severe allergy to other H2 blockers
Duodenal ulcer (open sore in the upper small intestine)
Gastric ulcer (open sore in the stomach)
Esophagitis (inflammation of the esophagus) and heartburn due to GERD
Prevention and treatment of heartburn (gastroesophageal reflux disease or GERD)
Gastric ulcer (open sore in the stomach)
Duodenal ulcer (open sore in the first part of the small intestine)
Heartburn (GERD)
Erosive esophagitis due to GERD (inflammation of the esophagus)
Other conditions that cause too much stomach acid secretion (i.e., Zollinger-Ellison syndrome)
Heartburn related to indigestion and sour stomach - OTC only
Erosive gastroesophageal reflux disease (GERD) - prescription only
Gastric and duodenal ulcers - prescription only
Conditions that cause too much stomach acid (such as Zollinger-Ellison syndrome) - prescription only
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Iwagami, M., et al. (2021). Risk of cancer in association with ranitidine and nizatidine vs other H2 blockers: Analysis of the Japan Medical Data Center Claims Database 2005–2018. Drug Safety.
Katz, P. O., et al. (2022). ACG clinical guideline for the diagnosis and management of gastroesophageal reflux disease. The American Journal of Gastroenterology.
Kovacs, T. O., et al. (1987). The effect of an oral evening dose of nizatidine on nocturnal and peptone-stimulated gastric acid and gastrin secretion. Scandinavian Journal of Gastroenterology. Supplement.
Nugent, C. C., et al. (2024). H2 blockers. StatPearls.
U.S. Food and Drug Administration. (2020). FDA updates and press announcements on NDMA in Zantac (ranitidine).
U.S. Food and Drug Administration. (2024). Information about nitrosamine impurities in medications.
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