ranitidine : Complexes, Storage & Clinical Research on Healthline.com

Affinity for CYP isoenzyme system is about 10% that of cimetidine; inhibition of CYP isoenzyme system is 2.4 times less than cimetidine.

May minimally inhibit hepatic metabolism of some drugs, or affect bioavailability by another mechanism (e.g., pH-dependent absorption, altered volume of distribution).

Specific Drugs, Foods, and Laboratory Tests

Drug, Food, or Test	Interaction	Comments
Acetaminophen	Dose-dependent inhibition of acetaminophen metabolism in vitro
Alcohol	Moderate alcohol consumption by individuals receiving concurrent ranitidine unlikely to result in clinically important alterations of blood alcohol concentration and/or alcohol metabolism	Controversy about psychomotor impairment potential; observe usual precautions about alcohol intake and hazardous tasks requiring mental alertness or physical coordination
Antacids	Low doses (10–15 mEq HCl neutalizing capacity/10 mL) do not appear to decrease absorption or plasma concentrations of ranitidine Higher doses (e.g., 150 mEq HCl neutralizing capacity/30 mL) decrease absorption by 33%, decrease plasma concentrations, and AUC
Atenolol	Atenolol pharmacokinetics apparently not affected
Benzodiazepines (e.g., diazepam, lorazepam, midazolam, triazolam)	Diazepam AUC, mean half-life not substantially affected Lorazepam elimination half-life, volume of distribution, clearance unaffected Midazolam oral bioavailability may be increased by ranitidine Triazolam oral bioavailability may be increased by elevated gastric pH clinical importance unknown	Observe carefully for signs of midazolam-induced respiratory and CNS depression; decrease midazolam dosage if required
Food	Does not appear to decrease absorption or plasma concentrations of ranitidine
Metoprolol	Increased metoprolol AUC, peak serum concentration, elimination half-life
Multistix®, test for urine protein	False positive	Use sulfosalicylic acid reagent for urinary protein determinations while using ranitidine
Nifedipine	Nifedipine AUC increased by 30%
Phenytoin	Phenytoin serum concentrations unaffected
Propantheline	Appears to delay absorption and increases peak serum concentrations of ranitidine; biovailability increased about 23% with concomitant administration
Propranolol	Propranolol mean serum concentrations not substantially affected
Smoking	Adversely affects duodenal ulcer healing and decreases ranitidine efficacy; number of cigarettes/day apparently does not influence healing rate
Theophylline	Ranitidine appparently does not alter theophylline clearance
Vitamin B₁₂	Vitamin B₁₂ malabsorption and deficiency may occur with long-term ranitidine therapy
Warfarin	Increased or decreased PT reported	Pharmacokinetic studies: up to 400 mg daily had no effect on warfarin clearance or PT

Ranitidine Hydrochloride
GG 705 150 mg	N 544 / 150 150 mg	N 547 / 300 300 mg	N 544 / 150 150 mg
GG 706 300 mg	WATSON 760 150 mg	GG 615 / GG 615 300 mg	WATSON 761 300 mg
APO 025 150 mg	par 545 300 mg
Zantac 150
Glaxo / ZANTAC 150 150 mg
Zantac 300
ZANTAC 300 / Glaxo 300 mg
Zantac 75
Z / 75 75 mg

Drug Notebook

Generic Name: ranitidine

Drug Interactions

Specific Drugs, Foods, and Laboratory Tests