nizatidine

Therapeutic Classification: antiulcer agents

Pharmacologic Classification: histamine h2 antagonists

Indications ⬆ ⬇

REMS

Duodenal ulcers and benign gastric ulcers.
Maintenance therapy for duodenal ulcers after healing of active ulcer(s).
Gastroesophageal reflux disease (GERD).

Action ⬆ ⬇

Inhibits the action of histamine at the H₂-receptor site located primarily in gastric parietal cells, resulting in inhibition of gastric acid secretion.

Therapeutic effects:

Healing and prevention of ulcers.
Decreased symptoms of GERD.
Decreased secretion of gastric acid.

Pharmacokinetics ⬆ ⬇

Absorption: 70–95% absorbed after oral administration.

Distribution: Well distributed to tissues.

Metabolism/Excretion: Undergoes some hepatic metabolism; at least 1 metabolite has histamine blocking activity. 60% excreted unchanged by the kidneys.

Half-Life: 1.6 hr.

Time/Action Profile ⬆ ⬇

ROUTE	ONSET	PEAK	DURATION
PO	unknown	unknown	8–12 hr

Contraind./Precautions ⬆ ⬇

Contraindicated in:

Hypersensitivity;
Lactation: Lactation.

Use Cautiously in:

Renal impairment (more susceptible to adverse CNS reactions; ↑ dosage interval recommended if CCr ≤50 mL/min);
OB: Safety not established in pregnancy;
Geri: Older adults are more susceptible to adverse CNS reactions; dose ↓ recommended.

Adv. Reactions/Side Effects ⬆ ⬇

Endo: gynecomastia

GI: constipation, diarrhea, drug-induced hepatitis, nausea

GU: ↓sperm count, erectile dysfunction

Hemat: AGRANULOCYTOSIS, APLASTIC ANEMIA, anemia, neutropenia, thrombocytopenia

Neuro: confusion, dizziness, drowsiness, hallucinations, headache

Misc: hypersensitivity reactions

Interactions ⬆ ⬇

Drug-drug:

↓absorption of ketoconazole.
Antacids andsucralfate↓ absorption.

Route/Dosage ⬆ ⬇

PO (Adults ): Short-term treatment of active ulcers: 300 mg once daily at bedtime. Duodenal ulcer prophylaxis: 150 mg once daily at bedtime.GERD: 150 mg twice daily. OTC use: 75 mg 30–60 min before foods/beverages expected to cause symptoms.

Renal Impairment

PO (Adults ): Short-term treatment of active ulcers: CCr 20–50 mL/min: 150 mg once daily; CCr <20 mL/min: 150 mg every other day; Duodenal ulcer prophylaxis: CCr 20–50 mL/min: 150 mg every other day; CCr <20 mL/min: 150 mg every 3 days.

Availability ⬆ ⬇

(Generic available)

Capsules: 150 mg; 300 mg

Assessment ⬆ ⬇

Assess patient for epigastric or abdominal pain and frank or occult blood in the stool, emesis, or gastric aspirate.
Assess geriatric and debilitated patients routinely for confusion. Report promptly.

Lab Test Considerations:

Monitor CBC with differential periodically during therapy.
- Antagonizes effects of pentagastrin and histamine during gastric acid secretion testing. Avoid administration for 24 hr preceding the test.
- May cause false-negative results in skin tests using allergenic extracts. Histamine H antagonists should be discontinued 24 hr before the test.
- May cause an ↑ in serum transaminases and serum creatinine.
- May also cause ↓ parathyroid concentrations.
- May cause ↑ alkaline phosphatase concentrations or false-positive tests for urobilinogen.

Implementation ⬆ ⬇

Do not confuse nizatidine with tizanidine.
If antacids or sucralfate are used concurrently for relief of pain, avoid administration of antacids within 30 min–1 hr of nizatidine and take sucralfate 2 hr after nizatidine; may decrease the absorption of nizatidine.

Patient/Family Teaching ⬆ ⬇

Instruct patient to take medication as directed for the full course of therapy, even if feeling better. Take missed doses as soon as remembered but not if almost time for next dose. Do not double doses.
- Advise patients taking OTC preparations not to take the maximum dose continuously for more than 2 wk without consulting health care professional. Notify health care professional if difficulty swallowing occurs or abdominal pain persists.
- May cause drowsiness or dizziness. Caution patient to avoid driving or other activities requiring alertness until response to the drug is known.
- Advise patient to avoid alcohol, products containing aspirin or NSAIDs, and foods that may cause an increase in GI irritation.
- Inform patient that increased fluid and fiber intake and exercise may minimize constipation.
- Advise patient to report onset of black, tarry stools; fever; sore throat; diarrhea; dizziness; rash; confusion; or hallucinations to health care professional promptly.

Evaluation/Desired Outcomes ⬆ ⬇

Decrease in abdominal pain.
Prevention of gastric irritation and bleeding. Healing of duodenal ulcers can be seen by endoscopy. Therapy is continued for at least 6 wk in treatment of ulcers but not usually longer than 8 wk.
Decreased symptoms of GERD.

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Pronunciation ⬇

Classifications ⬆ ⬇