Dosing and uses of Axid (nizatidine)
Adult dosage forms and strengths
capsule
- 150mg
- 300mg
oral solution
- 15mg/mL
tablet
- 75mg
Active Duodenal Ulcer
300 mg PO qHS Or
150 mg PO q12hr
Most heal after 4 weeks
Duodenal Ulcer Maintenance
150 mg PO qHs
Benign Gastric Ulcer
300 mg PO qHS Or
150 mg PO q12hr
GERD
150 mg PO q12hr Or
300 mg PO qHs
Renal Impairment
Active duodenal ulcer, gastric ulcer, GERd
- CrCl 20-50 mL/min: 150 mg PO qDay
- CrCl <20 mL/min: 150 mg PO qOTHERday
Duodenal ulcer maintenance
- CrCl 20-50 mL/min: 150 mg PO qOTHERday
- CrCl < 20 mL/min: 150 mg PO q3Days
Other Indications & Uses
Heartburn (OTC product)
Pediatric dosage forms and strengths
capsule
- 150mg
- 300mg
oral solution
- 15mg/mL
tablet
- 75mg
GERD
<12 years: 5-10 mg/kg/day PO divided q12hr (limited data)
Geriatric dosage forms and strengths
Active duodenal ulcer
300 mg PO qHS Or
150 mg PO q12hr
Most heal after 4 weeks
Duodenal ulcer maintenance
150 mg PO qHs
Benign gastric ulcer
300 mg PO qHS OR150 mg PO q12hr
GERD
150 mg PO q12hr Or
300 mg PO qHs
Axid (nizatidine) adverse (side) effects
>10%
Headache (17%)
1-10%
Abdominal pain
Anxiety
Constipation
Diarrhea
Dizziness
Insomnia
Nausea/vomiting
Pruritus
<1%
Anemia
Increased LFT's
Warnings
Contraindications
Hypersensitivity to nizatidine or other H2 receptor antagonists
Cautions
Adjust dosage in renal impairment
May see false positive urobilinogen secondary to nizatidine
Pregnancy and lactation
Pregnancy category: C
Lactation: crosses into breast milk, either discontinue nursing or the drug
Pregnancy categories
A: Generally acceptable. Controlled studies in pregnant women show no evidence of fetal risk.
B: May be acceptable. Either animal studies show no risk but human studies not available or animal studies showed minor risks and human studies done and showed no risk.
C: Use with caution if benefits outweigh risks. Animal studies show risk and human studies not available or neither animal nor human studies done.
D: Use in LIFE-THREATENING emergencies when no safer drug available. Positive evidence of human fetal risk.
X: Do not use in pregnancy. Risks involved outweigh potential benefits. Safer alternatives exist.
NA: Information not available.
Pharmacology of Axid (nizatidine)
Mechanism of action
H2-receptor antagonist; blocks H2-receptors of gastric parietal cells, leading to inhibition of gastric secretions
Pharmacokinetics
Half-Life: 2.5-3hr (PO); 2-2.5hr (IV)
Peak Plasma Time: 2-3hr (PO); <15 min (IM)
Absorption: 50% (oral)
Bioavailability: 48-50% (PO); 90-100% (IM)
Protein Bound: 15%
Vd: 0.8-1.5 L/kg
Metabolism: Liver, unlike cimetidine, nizatidine does not inhibit microsomal enzymes
Metabolites: N-desmethylnizatidine (active), nizatidine N-oxide (inactive), nizatidine S-oxide (inactive)
Dialyzable: No
Clearance
- Total Body: 660-1000 mL/min
- Renal: 500 mL/min (Not dialyzable by HD)
Excretion
- Urine: 30% (PO); 70% (IV)
- Feces: <6%
