The P-I-E-N-O Parkinsn's List Drug Database
nizatidine / AxidTM
GASTRO REFLUX:
Ulcer
Description: Nizatidine is an oral HA-receptor antagonist similar to cimetidine, famotidine, and ranitidine. Nizatidine currently is indicated for gastroesophageal reflux disease (GERD), shortterm and maintenance treatment of duodenal ulcer, and short-term treatment of active benign gastric ulcer. Nizatidine was approved by the FDA in April 1988 and became the fourth HAantagonist available for use in the United States. On September 28, 1995, a FDA advisory committee recommended that nizatidine be approved as a non-prescription product.
Mechanism of Action: Nizatidine competitively inhibits the binding of histamine to the HA-receptors on the gastric basolateral membrane of parietal cells, reducing basal and nocturnal gastric acid secretions. The drug also decreases the gastric acid response to stimuli such as food, caffeine, insulin, betazole, or pentagastrin. Nizatidine reduces the total volume of gastric juice, thus indirectly decreasing pepsin secretion. The drug does not appear to alter gastric motility, gastric emptying, esophageal pressures, biliary secretions, or pancreatic secretions. Nizatidine may aid in gastromucosal healing, and it may protect the mucosa from the irritant effects caused by aspirin and nonsteroidal antiinflammatory agents.
Pharmacokinetics: Nizatidine is administered orally. The bioavailability of nizatidine is about 95% in patients with normal renal function and about 75% in patients with renal failure. The presence of food in the GI tract appears to increase the absorption of nizatidine. The drug is roughly 35% protein-bound, but the distribution is unknown.
Approximately 7% of an oral dose is metabolized in the liver to N2monodesmethylnizatidine, which has HA-antagonist activity. Approximately 60% of unchanged drug and its metabolites are excreted in the urine and approximately 6% in the feces. Nizatidine is eliminated by both glomerular filtration and active tubular secretion. The elimination half-life is 1-2 hours and increases to 3.5-11 hours in functionally anephric patients.
CONTRAINDICATIONS/PRECAUTIONS: Nizatidine is classified as pregnancy category C. The effects of the drug on the fetus are unknown. Risk-benefit analysis should be considered during pregnancy and in women expecting to become pregnant.
Nizatidine is excreted into breast milk. Animal studies have documented transient growth depression in immature animals receiving nizatidine via breast milk. Nizatidine should not be used in women who are breast-feeding.
Nizatidine should be used with caution in patients with renal impairment because the drug is eliminated via glomerular filtration. Nizatidine can be prescribed to patients with renal impairment if appropriate dosage reductions are made.
DRUG INTERACTIONS: Ketoconazole requires an acidic environment for oral absorption, so therapy with nizatidine can reduce the bioavailability of ketoconazole. Because the effects on intragastric pH are sustained, separating the time of administration of these two drugs may not alleviate the problem. Fluconazole is not affected by gastric pH and may be an alternative for ketoconazole.
Didanosine, ddI is an acid-labile compound. Administration of nizatidine prior to didanosine was shown to increase didanosine serum concentrations, although the magnitude was slight.
Nizatidine may increase concentrations of salicylates and salicylate AUCs in patients receiving high-dose aspirin therapy. Nizatidine may cause an inhibition of salicylate renal excretion.
Antacids can slightly decrease nizatidine absorption. Administer at least an hour apart.
ADVERSE REACTIONS: The incidence of adverse reactions occuring during nizatadine therapy is often no higher than the incidence occuring during placebo administration. Fatigue (2.4%), diaphoresis (1%), and pruritus and urticaria (0.5%) are the most common adverse reactions.
GI adverse reactions have been reported in patients receiving nizatidine. These reactions include diarrhea or constipation, flatulence, nausea/vomiting and abdominal pain. Although rare, hepatitis, jaundice, and elevated hepatic enzymes have been reported with nizatidine.
Reversible mental status changes, including agitation, delirium, hallucinations, hostility, paranoia, depression, and disorientation, have been reported following nizatidine therapy. Other CNS adverse reactions that have been reported during nizatidine therapy include dizziness, headache, and somnolence. A review of central nervous system reactions to HA-blockers revealed that the incidence rate varies widely depending on the specific report, and that no single HA-antagonist is more likely to induce CNS reactions than another.I
A number of other adverse reactions have been reported with nizatidine. These reactions include asymptomatic ventricular tachycardia, hyperuricemia, eosinophilia, and fever.
PATIENT INFORMATION:
What do nizatidine capsules do?
Nizatidine (AxidTM ) is a type of antihistamine that blocks the release of stomach acid. Nizatidine is used to treat gastric and duodenal ulcers. It can relieve ulcer pain and discomfort, and the heartburn from gastroesophageal reflux disease. Generic nizatidine capsules are not yet available.
What should my doctor, dentist, or pharmacist know before I take nizatidine?
They need to know if you have any of these conditions:
How should I take this medicine?
Take nizatidine capsules by mouth. Follow the directions on the prescription label. Swallow the capsules with a drink of water. If you only take nizatidine once a day take it at bedtime. Take your doses at regular intervals. Do not take your medicine more often than directed.
Special precautions for use in children:
This medicine is not for children under 18 years old.
What if I miss a dose?
If you miss a dose, take it as soon as you can. If it is almost time for your next dose, take only that dose. Do not take double or extra doses.
What other medicines can interact with nizatidine?
Tell your doctor or pharmacist: about all other medicines you are taking, including non-prescription medicines; if you are a frequent user of drinks with caffeine or alcohol; if you smoke; or if you use illegal drugs. These may affect the way your medicine works. Check before stopping or starting any of your medicines.
What side effects may I notice from taking nizatidine?
Side effects with nizatidine are infrequent but include:
Let your doctor know if you get any of these side effects.
What do I need to watch for while I take nizatidine?
Tell your doctor if your ulcer pain does not improve or gets worse. You may need to take this medicine for several days as prescribed before your symptoms improve. Finish the full course of tablets prescribed by your doctor even if you feel better.
Do not self-medicate with aspirin, ibuprofen or other antiinflammatory medicines; these can aggravate your ulcer and may make it bleed.
Do not smoke cigarettes or drink alcohol; these increase irritation in your stomach and can lengthen the time it will take for your ulcers to heal.
If you need to take an antacid you should take it at least 1 hour before or 1 hour after nizatidine. Nizatidine will not be as effective if taken at the same time as an antacid.
If you get black, tarry stools or vomit up what looks like coffee grounds, call your doctor at once. You may have a bleeding ulcer.
Where can I keep my medicine?
Keep out of the reach of children in a container that small children cannot open.
Store at room temperature between 15 and 30C (59 and 86F). Throw away any unused medicine after the expiration date.
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