Zantac 75

Quantities per tablet

Active Ingredient:

Ranitidine Hydrochloride 84mg

(equivalent to ranitidine 75mg)

Tablet

Symptomatic relief of heartburn, indigestion, acid indigestion and hyperacidity.

For prevention of acid indigestion, indigestion, hyperacidity and heartburn associated with consuming food and drink.

Route of Administration

Oral

Dosage

Adults (including the elderly) and children 16 years of age and older:

Swallow one Zantac 75 tablet whole, with a drink of water, as soon as you have symptoms. If symptoms persist for more than one hour or return, take another tablet. Do not take more than four tablets in 24 hours.

For prevention of acid indigestion, indigestion, hyperacidity and heartburn associated with consuming food and drink, swallow one tablet with water, half to one hour beforehand.

Patients will be advised not to take the tablets for more than 2 weeks continuously and to consult their doctor if symptoms get worse or persist after 2 weeks treatment.

Children under 16 years

Not recommended for children under 16 years of age.

Ranitidine is contraindicated for patients known to be hypersensitive to the drug or any of the ingredients of Zantac 75 tablets.

Treatment with a histamine H₂-antagonist may mask symptoms associated with carcinoma of the stomach and may therefore delay diagnosis of the condition.

Ranitidine is excreted via the kidney and so plasma levels of the drug are increased in patients with renal impairment (creatinine clearance less than 50 ml/min). Zantac 75 is not suitable for these patients without medical supervision.

Patients who are taking non-steroidal anti-inflammatory drugs especially in those with a history of peptic ulcer and the elderly should be referred to their doctor before taking Zantac 75. Current evidence shows that ranitidine protects against NSAID associated ulceration in the duodenum and not in the stomach.

Although clinical reports of acute intermittent porphyria associated with ranitidine administration have been rare and inconclusive, ranitidine should be avoided in patients with a history of this condition.

The Patient Information Leaflet and Label advises the patient not to take the maximum daily dose for more than 14 consecutive days unless advised by their doctor.

The product is not indicated in the following patients without seeking their doctor's or pharmacist's advice:

• Patients with renal impairment (creatinine clearance less than 50 ml/min) and/or hepatic impairment.

• Patients under regular medical supervision for other reasons.

• Patients suffering from any other illness or taking medications either physician prescribed or self prescribed.

• Patients of middle age or older with new or recently changed symptoms of indigestion.

• Patients with unintended weight loss in association with symptoms of indigestion.

In patients such as the elderly, persons with chronic lung disease, diabetes or the immunocompromised, there may be an increased risk of developing community acquired pneumonia.

A large epidemiological study showed an increased risk of developing community acquired pneumonia in current users of ranitidine alone versus those who had stopped treatment, with an observed adjusted relative risk increase of 1,82 (95% CI 1,26-2,64).

Ranitidine has the potential to affect the absorption, metabolism or renal excretion of other drugs. The altered pharmacokinetics may necessitate dosage adjustment of the affected drug or discontinuation of treatment.

Interactions occur by several mechanisms including:

1) Inhibition of cytochrome P450-linked mixed function oxygenase system:

Ranitidine at usual therapeutic doses does not potentiate the actions of drugs which are inactivated by this enzyme such as diazepam, lidocaine, phenytoin, propranolol and theophylline.

There have been reports of altered prothrombin time with coumarin anticoagulants (e.g. warfarin). Due to the narrow therapeutic index, close monitoring of increased or decreased prothrombin time is recommended during concurrent treatment with ranitidine.

2) Alteration of gastric pH:

The bioavailability of certain drugs may be affected. This can result in either an increase in absorption or a decrease in absorption.

Zantac crosses the placenta but therapeutic doses administered to obstetric patients in labour or undergoing caesarean section have been without any adverse effect on labour, delivery or subsequent neonatal progress. Like other over the counter drugs, Zantac 75 should not be taken during pregnancy without consulting a doctor. Ranitidine is also excreted in human breast milk and women who are breast feeding will be advised to speak to their doctor before taking Zantac 75 Tablets.

No known effect.

The following convention has been utilised for the classification of undesirable effects: very common (>1/10), common (>1/100, <1/10), uncommon (>1/1000, <1/100), rare (>1/10,000, <1/1000), very rare (1/10,000).

Adverse event frequencies have been estimated from spontaneous reports from post-marketing data.

Zantac is very specific in action and accordingly no particular problems are expected following overdosage with the drug. Symptomatic and supportive therapy should be given as appropriate. If need be, the drug may be removed from the plasma by haemodialysis.

Zantac is a specific rapidly acting histamine H₂-antagonist. It inhibits basal and stimulated secretion of gastric acid, reducing both the volume and the acid and pepsin content of the secretion. Zantac has a long duration of action and a single 75mg dose suppresses gastric acid secretion for up to twelve hours.

Clinical studies have shown that Zantac 75 mg can relieve the symptoms of excess acid production for up to twelve hours.

Absorption

Following oral administration of 150 mg ranitidine, maximum plasma concentrations (300 to 550 ng/mL) occurred after 1-3 hours. Two distinct peaks or a plateau in the absorption phase result from reabsorption of drug excreted into the intestine. The absolute bioavailability of ranitidine is 50-60%, and plasma concentrations increase proportionally with increasing dose up to 300 mg.

Absorption is not significantly impaired by food or antacids.

Distribution

Ranitidine is not extensively bound to plasma proteins (15%), but exhibits a large volume of distribution ranging from 96 to 142 L.

Metabolism

Ranitidine is not extensively metabolised. The fraction of the dose recovered as metabolites includes 6% of the dose in urine as the N-Oxide, 2% as the S-Oxide, 2% as desmethyl ranitidine and 1-2% as the furoic acid analogue.

Elimination

Plasma concentrations decline bi-exponentially, with a terminal half-life of 2-3 hours. The major route of elimination is renal. After IV administration of 150 mg ³H-ranitidine, 98% of the dose was recovered, including 5% in the faeces and 93% in the urine, of which 70% was unchanged parent drug. After oral administration of 150 mg ³H-ranitidine, 96% of the dose was recovered, 26% in the faeces and 70% in urine of which 35% was unchanged parent drug. Less than 3% of the dose is excreted in bile. Renal clearance is approximately 500mL/min, which exceeds glomerular filtration indicating net renal tubular secretion.

Special Patient Populations

• Patients over 50 years of age

In patients over 50 years of age, half-life is prolonged (3-4 h) and clearance is reduced, consistent with the age-related decline of renal function. However, systemic exposure and accumulation are 50% higher. This difference exceeds the effect of declining renal function, and indicates increased bioavailability in older patients.

Extensive studies have been carried out in animals. The pharmacology of ranitidine hydrochloride shows it to be a surmountable H₂ receptor antagonist which produces an inhibition of gastro acid secretion. Extensive toxicological investigators have been conducted which predicted a very safe profile for clinical use. This safety has since been confirmed by extensive use in patients for many years.

Tablet Core

Microcrystalline Cellulose NF

Magnesium Stearate

Filmcoat (Aqueous)

Methylhydroxypropylcellulose (E464)*

Titanium Dioxide (E171)*

Synthetic red iron oxide (E172)*

Triacetin*

Purified Water

(Not detected in final formulation)

* As Opadry Pink YS-1-1441-G

None known.

60 months.

None necessary.

Push through double foil blisters of 2, 5, 6, 10, 12, 14, 18, 20, 24, 30, 36 or 48 tablets.

No special instructions.

Beecham Group Plc

980 Great West Road

Brentford

Middlesex

TW8 9GS

Trading as

GlaxoSmithKline Consumer Healthcare, Brentford, TW8 9GS, U.K.

PL 00079/0619

27/09/1994 / 15/08/2007

18/07/2011