Nizatidine has fewer drug interactions than cimetidine, but renal dosing and hypersensitivity remain key screening items.
Absolute contraindications include hypersensitivity to nizatidine or other H2 blockers. Relative precautions involve renal impairment, pregnancy/lactation counseling, and caution in patients needing PPI-level acid suppression.
Known hypersensitivity to nizatidine, other H2-receptor antagonists, or formulation components — prior immediate reactions (bronchospasm, anaphylaxis) require avoiding the class.
Creatinine clearance below 50 mL/min, because reduced renal excretion can lead to central nervous system effects; adjust the dose and extend intervals per labeling guidance.
History of acute porphyria; H2 blockers have precipitated attacks, so consult hematology before prescribing.
Chronic liver disease with elevated transaminases given reports of cholestatic hepatitis; obtain baseline liver tests and monitor if therapy extends beyond 2 weeks.
Suspected gastric malignancy; acid suppression can mask alarm symptoms, so evaluate weight loss, anemia, or persistent vomiting before empiric therapy.