Ranitidine

Oral
Benign gastric ulcer
Adult: 150 mg bid or 300 mg at bedtime for at least 4 weeks. Maintenance: 150 mg daily at bedtime.
Child: 3-11 years 4-8 mg/kg daily in 2 divided doses for 4 weeks or up to 8 weeks if needed. Max: 300 mg daily; ≥12 years Same as adult dose.
Renal impairment:

CrCl (ml/min)	Dosage Recommendation
<50	150 mg at night for 4-8 weeks. For patients with inadequate response, may adjust dose to 150 mg bid and may reduce back to maintenance treatment of 150 mg at night if required.

Oral
Duodenal ulcer
Adult: 150 mg bid or 300 mg at bedtime for at least 4 weeks. Maintenance: 150 mg daily at bedtime.
Child: 3-11 years 4-8 mg/kg daily in 2 divided doses for 4 weeks or up to 8 weeks if needed. Max: 300 mg daily; ≥12 years Same as adult dose.
Renal impairment:

CrCl (ml/min)	Dosage Recommendation
<50	150 mg at night for 4-8 weeks. For patients with inadequate response, may adjust dose to 150 mg bid and may reduce back to maintenance treatment of 150 mg at night if required.

Oral
Postoperative peptic ulcer
Adult: 150 mg bid for at least 4 weeks.
Renal impairment:

CrCl (ml/min)	Dosage Recommendation
<50	150 mg at night for 4-8 weeks. For patients with inadequate response, may adjust dose to 150 mg bid and may reduce back to maintenance treatment of 150 mg at night if required.

Oral
NSAID-associated ulceration
Adult: 150 mg bid or 300 mg at bedtime for 8-12 weeks. For prophylaxis of NSAID-associated duodenal ulcers: 150 mg bid given concomitantly with NSAID treatment.
Renal impairment:

CrCl (ml/min)	Dosage Recommendation
<50	150 mg at night for 4-8 weeks. For patients with inadequate response, may adjust dose to 150 mg bid and may reduce back to maintenance treatment of 150 mg at night if required.

Oral
Duodenal ulcers associated with H. pylori infection
Adult: 300 mg at bedtime or 150 mg bid given with oral amoxicillin and metronidazole for 2 weeks. Continue therapy without antibiotics for another 2 weeks. Patients who have responded to short-term therapy, particularly those with history of recurrent ulcers: Reduce maintenance treatment at a dose of 150 mg at bedtime.
Renal impairment:

CrCl (ml/min)	Dosage Recommendation
<50	150 mg at night for 4-8 weeks. For patients with inadequate response, may adjust dose to 150 mg bid and may reduce back to maintenance treatment of 150 mg at night if required.

Oral
Gastro-oesophageal reflux disease
Adult: Symptomatic relief: 150 mg bid for 2 weeks; may be continued for a further 2 weeks in patients with inadequate response. Acute reflux oesophagitis: 150 mg bid or 300 mg at bedtime for up to 8 weeks or, if necessary, up to 12 weeks. Moderate to severe oesophagitis: 150 mg 4 times daily for up to 12 weeks. Long-term management of reflux oesophagitis: 150 mg bid.
Child: 3-11 years 5-10 mg/kg daily in 2 divided doses. Max: 600 mg daily; ≥12 years Same as adult dose.
Renal impairment:

CrCl (ml/min)	Dosage Recommendation
<50	150 mg at night for 4-8 weeks. For patients with inadequate response, may adjust dose to 150 mg bid and may reduce back to maintenance treatment of 150 mg at night if required.

Oral
Hypersecretory conditions
Adult: For the treatment of pathological conditions such as Zollinger-Ellison syndrome: 150 mg bid, may be administered more frequently in some cases. Doses up to 6,000 mg daily have been used. Dosages may be adjusted to individual patient needs and continued as long as clinically indicated.
Renal impairment:

CrCl (ml/min)	Dosage Recommendation
<50	150 mg at night for 4-8 weeks. For patients with inadequate response, may adjust dose to 150 mg bid and may reduce back to maintenance treatment of 150 mg at night if required.

Oral
Chronic episodic dyspepsia
Adult: 150 mg bid for up to 6 weeks.
Renal impairment:

CrCl (ml/min)	Dosage Recommendation
<50	150 mg at night for 4-8 weeks. For patients with inadequate response, may adjust dose to 150 mg bid and may reduce back to maintenance treatment of 150 mg at night if required.

Oral
Prophylaxis of gastrointestinal haemorrhage from stress ulceration
Adult: 150 mg bid as a substitute for IV inj once oral therapy is possible.
Renal impairment:

CrCl (ml/min)	Dosage Recommendation
<50	150 mg at night for 4-8 weeks. For patients with inadequate response, may adjust dose to 150 mg bid and may reduce back to maintenance treatment of 150 mg at night if required.

Oral
Prophylaxis of acid aspiration during general anaesthesia
Adult: 150 mg given 2 hours prior to induction of anaesthesia and also when possible, a 150 mg dose given on the previous evening. Obstetric patients in labour: 150 mg may be given at the start of labour and may be repeated 6 hourly, as necessary.
Renal impairment:

CrCl (ml/min)	Dosage Recommendation
<50	150 mg at night for 4-8 weeks. For patients with inadequate response, may adjust dose to 150 mg bid and may reduce back to maintenance treatment of 150 mg at night if required.

Parenteral
Duodenal ulcer
Adult: 50 mg via IM or slow IV inj over 2 minutes or via intermittent IV infusion at a rate of 25 mg/hour for 2 hours. Dose may be repeated 6-8 hourly.
Child: 6 months to 11 years Initially, 2 mg/kg or 2.5 mg/kg (Max: 50 mg) via slow IV inj over 10 minutes (either with a syringe pump followed by a 3 mL flush with NaCl 0.9% over 5 minutes or after dilution with NaCl 0.9% to 20 mL). Maintenance of pH >4: 1.5 mg/kg 6-8 hourly via intermittent IV infusion. Alternatively, 0.45 mg/kg via slow IV inj over 2 minutes as loading dose followed by 0.15 mg/kg/hour via continuous IV infusion; ≥12 years Same as adult dose.
Renal impairment:

CrCl (ml/min)	Dosage Recommendation
<50	May reduce dose to 25 mg.

Reconstitution: IV: Intermittent bolus inj: Dilute 50 mg in NaCl 0.9% inj or other compatible IV solution to a Max concentration of 2.5 mg/mL (20 mL). Intermittent infusion: Dilute 50 mg in dextrose 5% in water or other compatible IV solution to a Max concentration of 0.5 mg/mL (100 mL).

Parenteral
Benign gastric ulcer
Adult: 50 mg via IM or slow IV inj over 2 minutes or via intermittent IV infusion at a rate of 25 mg/hour for 2 hours. Dose may be repeated 6-8 hourly.
Child: 6 months to 11 years Initially, 2 mg/kg or 2.5 mg/kg (Max: 50 mg) via slow IV inj over 10 minutes (either with a syringe pump followed by a 3 mL flush with NaCl 0.9% over 5 minutes or after dilution with NaCl 0.9% to 20 mL). Maintenance of pH >4: 1.5 mg/kg 6-8 hourly via intermittent IV infusion. Alternatively, 0.45 mg/kg via slow IV inj over 2 minutes as loading dose followed by 0.15 mg/kg/hour via continuous IV infusion; ≥12 years Same as adult dose.
Renal impairment:

CrCl (ml/min)	Dosage Recommendation
<50	May reduce dose to 25 mg.

Reconstitution: IV: Intermittent bolus inj: Dilute 50 mg in NaCl 0.9% inj or other compatible IV solution to a Max concentration of 2.5 mg/mL (20 mL). Intermittent infusion: Dilute 50 mg in dextrose 5% in water or other compatible IV solution to a Max concentration of 0.5 mg/mL (100 mL).

Parenteral
Hypersecretory conditions
Adult: For the treatment of pathological conditions such as Zollinger-Ellison syndrome: 50 mg via IM or slow IV inj over 2 minutes or via intermittent IV infusion at a rate of 25 mg/hour for 2 hours. Dose may be repeated 6-8 hourly.
Renal impairment:

CrCl (ml/min)	Dosage Recommendation
<50	May reduce dose to 25 mg.

Reconstitution: IV: Intermittent bolus inj: Dilute 50 mg in NaCl 0.9% inj or other compatible IV solution to a Max concentration of 2.5 mg/mL (20 mL). Intermittent infusion: Dilute 50 mg in dextrose 5% in water or other compatible IV solution to a Max concentration of 0.5 mg/mL (100 mL).

Parenteral
Prophylaxis of acid aspiration during general anaesthesia
Adult: 50 mg via IM or slow IV inj 45-60 minutes prior to induction of anaesthesia.
Renal impairment:

CrCl (ml/min)	Dosage Recommendation
<50	May reduce dose to 25 mg.

Reconstitution: IV: Intermittent bolus inj: Dilute 50 mg in NaCl 0.9% inj or other compatible IV solution to a Max concentration of 2.5 mg/mL (20 mL). Intermittent infusion: Dilute 50 mg in dextrose 5% in water or other compatible IV solution to a Max concentration of 0.5 mg/mL (100 mL).

Intravenous
Prophylaxis of gastrointestinal haemorrhage from stress ulceration
Adult: 50 mg via slow IV inj as a priming dose, followed by 0.125-0.25 mg/kg/hour via continuous infusion. Continue treatment until oral feeding commences.
Renal impairment:

CrCl (ml/min)	Dosage Recommendation
<50	May reduce dose to 25 mg.

Reconstitution: IV: Intermittent bolus inj: Dilute 50 mg in NaCl 0.9% inj or other compatible IV solution to a Max concentration of 2.5 mg/mL (20 mL). Intermittent infusion: Dilute 50 mg in dextrose 5% in water or other compatible IV solution to a Max concentration of 0.5 mg/mL (100 mL).

May be taken with or without food.

Patient with chronic lung disease or diabetes. Immunocompromised or severely ill patient. Patients taking NSAIDs (especially in those with a history of peptic ulcer). Avoid use in patients with history of acute porphyria. Smokers. Renal and hepatic impairment. Children and elderly. Pregnancy and lactation. Monitoring Parameters Rule out malignancy prior to initiation of therapy in patients with gastric ulcers and patients of middle age and over with new or recently changed dyspeptic symptoms. Measure intragastric pH and try to maintain pH >4 when used to prevent stress-related gastrointestinal bleeding. Monitor AST, ALT, serum creatinine; occult blood with gastrointestinal bleeding; gastric acid secretion (when used for Zollinger-Ellison syndrome); signs or symptoms of CNS changes (confusion, depression, hallucinations) and gastrointestinal disturbance.

Significant: Elevated ALT levels (particularly with high doses or prolonged IV use), may reduce the absorption of vitamin B₁₂ (prolonged use), may increase the risk of developing community-acquired pneumonia. Rarely, reversible mental confusion, bradycardia associated with rapid administration of inj (particularly in patients with predisposing factors to cardiac rhythm disturbances), may precipitate acute porphyric attacks. Blood and lymphatic system disorders: Rarely, leucopenia, thrombocytopenia, granulocytopenia, agranulocytosis, pancytopenia (sometimes with marrow hypoplasia or aplasia), aplastic anaemia, acquired immune haemolytic anaemia. Cardiac disorders: Rarely, atrioventricular block, tachycardia, premature ventricular beats. Ear and labyrinth disorders: Rarely, vertigo. Eye disorders: Rarely, reversible blurred vision. Gastrointestinal disorders: Abdominal pain or discomfort, constipation, diarrhoea, nausea, vomiting. Rarely, acute pancreatitis. General disorders and administration site conditions: Transient pain (IM), local burning or itching (IV) at the site of inj. Rarely, malaise. Hepatobiliary disorders: Rarely, hepatitis (with or without jaundice), hepatic failure. Immune system disorders: Rarely, hypersensitivity reactions including urticaria, angioneurotic oedema, fever, bronchospasm, hypotension, and chest pain; very rarely, anaphylactic shock. Investigations: Rarely, transient and reversible LFT changes, elevated plasma creatinine. Musculoskeletal and connective tissue disorders: Rarely, arthralgia, myalgia. Nervous system disorders: Rarely, headache (sometimes severe), dizziness, reversible involuntary movement disorders. Psychiatric disorders: Rarely, agitation, depression, hallucinations, insomnia, somnolence. Renal and urinary disorders: Rarely, acute interstitial nephritis. Reproductive system and breast disorders: Rarely, reversible impotence, breast symptoms and breast conditions (e.g. gynaecomastia and galactorrhoea). Respiratory, thoracic and mediastinal disorders: Dyspnoea. Skin and subcutaneous tissue disorders: Rarely, rash, erythema multiforme, alopecia. Vascular disorders: Rarely, vasculitis.

Symptoms: Abnormalities of gait, hypotension; transient adverse effects similar to those encountered in normal clinical experience. Management: Symptomatic and supportive treatment.

Altered prothrombin time with coumarin anticoagulants (e.g. warfarin). High doses of ranitidine may reduce excretion and increase the plasma levels of procainamide and active N-acetylprocainamide metabolite. May increase the absorption of midazolam, triazolam, and glipizide. May reduce the absorption of atazanavir, delavirdine, ketoconazole, and gefitinib. Decreases the exposure of erlotinib. Reduced absorption with high-dose (2 g) sucralfate.

May lead to false-positive tests for urine protein with Multistix^®.

Ranitidine competitively and reversibly inhibits histamine at the histamine H₂-receptors of the gastric parietal cells, thereby inhibiting gastric acid secretion and gastric volume and reducing hydrogen ion concentration.
Duration: 12 hours (oral).
Absorption: Readily absorbed from the gastrointestinal tract (oral); rapidly absorbed (IM). Bioavailability: 50-60% (oral); 90-100% (IM). Time to peak plasma concentration: 1-3 hours (oral); within 15 minutes (IM).
Distribution: Crosses the placenta and enters breast milk. Volume of distribution: 96-142 L. Plasma protein binding: Approx 15%.
Metabolism: Metabolised in the liver to N-oxide (major metabolite), S-oxide, and desmethylranitidine.
Excretion: Mainly via urine (oral: 70%, approx 35% as unchanged drug; IV: 93%, 70% as unchanged drug); faeces (oral: 26%; IV: 5%). Elimination half-life: 2-3 hours (oral); 2-2.5 hours (IV).

Intravenous: Store between 20-25°C. Protect from light and moisture. Storage recommendations may vary among individual products. Refer to specific product guidelines. Oral: Store between 20-25°C. Protect from light and moisture. Storage recommendations may vary among individual products. Refer to specific product guidelines. Parenteral: Store between 20-25°C. Protect from light and moisture. Storage recommendations may vary among individual products. Refer to specific product guidelines.

Antacids, Antireflux Agents & Antiulcerants

A02BA02 - ranitidine ; Belongs to the class of H2-receptor antagonists. Used in the treatment of peptic ulcer and gastro-oesophageal reflux disease (GERD).