ranitidine (Discontinued)

Brand and Other Names:Zantac, Zantac 150 Maximum Strength, more...Zantac 75
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Dosing & Uses


Dosage Forms & Strengths

injection solution

  • 25mg/mL


  • 15mg/mL


  • 75mg
  • 150mg
  • 300mg


  • 150mg
  • 300mg

FDA Safety Communication

On April 1, 2020, FDA requests removal of all ranitidine products (Zantac) from the market

For more information, see FDA Drug Safety Communication (link https://www.fda.gov/news-events/press-announcements/fda-requests-removal-all-ranitidine-products-zantac-market)

Health care professionals should stop prescribing and dispensing ranitidine to patients

Contact patients currently taking ranitidine, inform them of the reported contaminant N-Nitrosodimethylamine (NDMA) found in several ranitidine products, and request to discontinue medication

Discuss alternative medications approved for the same or similar uses as ranitidine that do not carry the same risks as NDMA

Gastroesophageal Reflux Disease

150 mg PO q12hr or 50 mg IM/IV q6-8hr

Gastric Ulcer, Benign

Treatment: 150 mg PO q12hr or 300 mg PO at bedtime

Maintenance of healing: 150 mg PO at bedtime

Erosive Esophagitis

Treatment: 150 mg PO q6hr or 50 mg IM/IV q6-8hr intermittent bolus or infusion; alternatively, 6.25 mg/hr IV by continuous infusion

Maintenance of healing: 150 mg PO q12hr

Hypersecretory Conditions

150 mg PO q12hr; up to 6 g/day used

Parenteral: 50 mg (2 mL) IM or intermittent IV bolus or infusion q6-8hr; not to exceed 400 mg/day; alternatively, 6.25 mg/hr continuous infusion

Dosing considerations

  • More frequent doses may be necessary; individualize dosage, and continue as long as indicated; dosages up to 6 g/day have been used for severe disease
  • Zollinger-Ellison syndrome: Start IV infusion at 1 mg/kg/hr, then adjust upward in 0.5 mg/kg/hr increments according to gastric acid output (not to exceed 2.5 mg/kg/hr or 220 mg/hr)  

Stress Ulcer Prophylaxis (Off-label)

150 mg PO or NG q12hr

50 mg (2 mL) IM or intermittent IV bolus or infusion q6-8hr; not to exceed 400 mg/day; alternatively, 6.25 mg/hr continuous infusion

Dosing Modifications

Renal impairment (CrCl <50 mL/min): 50 mg IV/IM q18-24hr or 150 mg PO once daily

Hepatic impairment: Dosage adjustment not necessary

Dosage Forms & Strengths

injection solution

  • 25mg/mL


  • 15mg/mL


  • 75mg
  • 150mg
  • 300mg


  • 150mg
  • 300mg

Active Duodenal/Gastric Ulcer

Treatment: 4-8 mg/kg PO q12hr; not to exceed 300 mg/day  

Maintenance: 2-4 mg/kg PO once daily; not to exceed 150 mg/day

Parenteral: 2-4 mg/kg/day IV divided q6-8hr; not to exceed 50 mg/dose or 200 mg/day

Gastroesophageal Reflux Disease

1 month - 16 years

5-10 mg/kg/day PO divided q12hr; not to exceed 300 mg/day  

Parenteral (Off-label): 2-4 mg/kg/day IV divided q6-8hr; not to exceed 50 mg/dose or 200 mg/day; alternatively, infusion at 1mg/kg/dose once followed by continuous infusion of 0.08-0.17 mg/kg/hr or 2-4 mg/kg/day

Erosive Esophagitis

1 month - 16 years

5-10 mg/kg/day PO divided q12hr; not to exceed 300 mg/day  

Parenteral (Off-label): 2-4 mg/kg/day IV divided q6-8hr; not to exceed 200 mg/day; alternatively, 1mg/kg/dose once followed by continuous infusion of 0.08-0.17 mg/kg/hr or 2-4 mg/kg/day

Neonates (Off-label)

Term Neonates (<29 days)

  • 2-4 mg/kg/day PO divided q8-12hr or 2 mg/kg/day IV divided q8hr  
  • Prophylaxis against dexamethasone associated ulceration: 0.031-1.25 mg/kg/hr during dexamethasone therapy to maintain gastric pH >4
  • Prophylaxis against stress ulceration: 2 mg/kg q12hr or 1.5 mg/kg IV q8hr; alternatively, 2 mg/kg over 10 min, followed by continuous infusion of 0.083 mg/kg/hr


Interaction Checker

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            Adverse Effects


            Headache (3%)


            Abdominal pain







            Hypersensitivity reaction



            Frequency Not Defined


            Necrotizing enterocolitis in fetus or newborn

            Pancreatitis (rare)

            Thrombocytopenia (rare)

            Pancytopenia (rare)

            Agranulocytosis (rare)

            Acquired immune hemolytic anemia (rare)

            Arthralgia (rare)

            Myalgia (rare)




            Hypersensitivity to ranitidine or components of the formulation


            If gastroesophageal reflux disease does not respond adequately in 6-8 weeks, do not increase dosage; prescribe proton pump inhibitor instead

            Prolonged treatment may lead to B12 malabsorption and subsequent vitamin B12 deficiency; degree of deficiency is dose-related and association stronger in females and younger in age (<30 years)

            Use caution in renal impairment; adjust dosage

            Use caution in hepatic impairment

            Elevation of ALT levels reported with higher doses (≥100 mg) or prolonged IV therapy (≥5 days); monitor for ALT levels for the remainder of treatment

            Avoid in patients with acute porphyria; may precipitate attack

            Symptom relieve does not rule out presence of gastric malignancy

            Reversible confusional state reported with use (linked to age >50 years and renal or hepatic impairment); clears within 3-4 days after discontinuation

            If patient taking a prescription drug, the patient should ask a doctor or a pharmacist whether acid reducers can be taken concomitantly with it

            Patients with kidney disease should ask doctor before use


            Pregnancy & Lactation

            Pregnancy category: B

            Lactation: Drug crosses into breast milk; discontinue drug, use caution

            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.



            Mechanism of Action

            H2-receptor antagonist; blocks H2 receptors of gastric parietal cells, leading to inhibition of gastric secretions


            Bioavailability: 50% (PO); 90-100% (IM)

            Onset: 1 hr (IV/PO)

            Duration: 4-5 hr (IV/IM); 4-6 hr (PO)

            Peak serum time: 15 min (IM); 2-3 hr (PO)


            Protein bound: 10-19%

            Vd: 1.4 L/kg (normal renal function)


            Metabolized in liver

            Metabolites: Ranitidine N-oxide, desmethylranitidine, ranitidine S-oxide (inactive)

            Enzymes inhibited: Unlike cimetidine, ranitidine does not inhibit microsomal enzymes


            Half-life: 2.5-3 hr (PO; increases to 4.8 hr with CrCl 25-35 mL/min); 2-2.5 hr (IV)

            Dialyzable: Yes (HD, PD)

            Renal clearance: 25 L/hr

            Total body clearance: 1.29-1.44 L/hr/kg

            Excretion: Urine (30% PO; 70% IV)



            IV Compatibilities

            Solution: Compatible with most common solvents

            Additive (partial list): Ampicillin(?), ciprofloxacin, dexamethasone, dobutamine, dopamine, epinephrine, erythromycin, floxacillin, fluconazole with ondansetron, furosemide, gentamicin, heparin, lidocaine, midazolam, norepinephrine (incompatible at 2 g), penicillin G potassium/sodium, potassium chloride, protamine sulfate, sodium nitroprusside, vancomycin

            Syringe (partial list): Atropine, dexamethasone, dimenhydrinate, diphenhydramine, dobutamine, dopamine, fentanyl, glycopyrrolate, heparin, hydromorphone, metoclopramide, morphine hydrochloride/sulfate, prochlorperazine, promethazine

            Y-site (partial list): Acyclovir, allopurinol, ceftazidime, ciprofloxacin, diltiazem, dobutamine, dopamine, epinephrine, esmolol, fentanyl, furosemide, heparin, linezolid, lorazepam, midazolam, morphine sulfate, nitroglycerin, norepinephrine, ondansetron, propofol, vecuronium, warfarin, zidovudine

            IV Incompatibilities

            Solution: D5W in LR(?)

            Additive: Amphotericin B, atracurium, cefamandole, cefazolin, cefoxitin, ceftazidime, cefuroxime, clindamycin(?), ethacrynate, insulin(?), phytonadione

            Syringe: Chlorpromazine(?), diazepam(?), hydroxyzine, lorazepam(?), methotrimeprazine, midazolam, papaveretum, pentobarbital, phenobarbital

            Y-site: Amphotericin B cholesteryl sulfate, hetastarch, insulin

            IV Administration

            Direct injection: 50 mg diluted to ≥20 mL with compatible IV infusion fluid and given over ≥5 minutes (4 mL/min)

            Intermittent infusion: 50 mg added to ≥100 mL of compatible IV solution and infused over 15-20 minutes

            Continuous infusion: 150 mg diluted in 250 mL of IV fluid and infused at 6.25 mg/hr for 24 hours

            IM Administration

            Administer undiluted


            Store at 4-30°C (39-86°F)

            Protect from light and excessive heat



            Medscape prescription drug monographs are based on FDA-approved labeling information, unless otherwise noted, combined with additional data derived from primary medical literature.