Consumer medicine information

GenRx Famotidine

Famotidine

BRAND INFORMATION

Brand name

GenRx Famotidine Tablets

Active ingredient

Famotidine

Schedule

S4

 

Consumer medicine information (CMI) leaflet

Please read this leaflet carefully before you start using GenRx Famotidine.

What is in this leaflet

Read this leaflet carefully before taking your medicine.

This leaflet answers some common questions about famotidine. It does not contain all the available information. It does not take the place of talking to your doctor or pharmacist.

The information in this leaflet was last updated on the date listed on the last page. More recent information on this medicine may be available.

Ask your doctor or pharmacist:

  • if there is anything you do not understand in this leaflet,
  • if you are worried about taking your medicine, or
  • to obtain the most up-to-date information.

You can also download the most up to date leaflet from www.apotex.com.au.

All medicines have risks and benefits. Your doctor has weighed the risks of you using this medicine against the benefits they expect it will have for you.

Pharmaceutical companies cannot give you medical advice or an individual diagnosis.

Keep this leaflet with your medicine. You may want to read it again.

What this medicine is used for

The name of your medicine is GenRx Famotidine Tablets. It contains the active ingredient famotidine.

Famotidine belongs to a group of medicines called H2-antagonists. It is used to:

It is used to:

  • Treat peptic ulcers.
    Depending on the position of the ulcer it is called a gastric or duodenal ulcer. A gastric ulcer occurs in the stomach and a duodenal ulcer occurs in the duodenum, which is the tube leading from the stomach. These ulcers usually cause pain and indigestion which is felt between the navel and the breast bone. The pain may occur before or after meals, or in the middle of the night. Famotidine also helps to stop duodenal ulcers coming back.
  • Treat Zollinger Ellison Syndrome, a rare condition caused by too much acid production in the stomach.
  • Treat and relieve symptoms of Gastro-Oesophageal Reflux Disease.
    This is caused by the reflux, or washing back, of food and acid from the stomach, into the oesophagus (food pipe). It causes a painful burning feeling in the chest which rises to the throat (heartburn), and usually occurs after eating or at night. It also helps to stop these symptoms from coming back.

Ask your doctor if you have any questions about why this medicine has been prescribed for you. Your doctor may have prescribed this medicine for another reason.

This medicine is available only with a doctor's prescription.

How it works

Famotidine belongs to a group of medicines called H2-antagonists or H2-blockers. It works by reducing the amount of acid in the stomach thereby reducing the pain and allowing the ulcer to heal.

This medicine is available only with a doctor's prescription.

There is no evidence that this medicine is addictive.

Use in children

This medicine should not be used in children.

Before you take this medicine

When you must not take it

Do not take this medicine if:

  • You have or have had any of the following:
  • You are pregnant.
    Famotidine may affect your developing baby if you take it during pregnancy.
  • You are breastfeeding.
    Famotidine may pass into human breast milk.
  • You are hypersensitive to, or have had an allergic reaction to, famotidine, any other type of H2- antagonist/blocker medicines or any of the ingredients listed at the end of this leaflet.
    Symptoms of an allergic reaction may include: cough, shortness of breath, wheezing or difficulty breathing; swelling of the face, lips, tongue, throat or other parts of the body; rash, itching or hives on the skin; fainting; or hay fever-like symptoms.
    If you think you are having an allergic reaction, do not take any more of the medicine and contact your doctor immediately or go to the Accident and Emergency department at the nearest hospital.
  • The expiry date (EXP) printed on the pack has passed.
  • The packaging is torn, shows signs of tampering or it does not look quite right.

Before you start to take it

Before you start taking this medicine, tell your doctor if:

  1. You have allergies to:
  • any other medicines
  • any other substances, such as foods, preservatives or dyes.
  1. You have or have had any medical conditions, especially the following:
  • kidney disease
  • cancer of the stomach
  • chronic lung disease
  • diabetes
  • you are immunocompromised.
  1. You are currently pregnant or you plan to become pregnant. Do not take this medicine whilst pregnant until you and your doctor have discussed the risks and benefits involved.
  2. You are currently breastfeeding or you plan to breast-feed. Do not take this medicine whilst breastfeeding until you and your doctor have discussed the risks and benefits involved.
  3. You are planning to have surgery or an anaesthetic.
  4. You are currently receiving or are planning to receive dental treatment.
  5. You are taking or are planning to take any other medicines. This includes vitamins and supplements that are available from your pharmacy, supermarket or health food shop.

Some medicines may affect the way other medicines work.

How to take this medicine

Follow carefully all directions given to you by your doctor. Their instructions may be different to the information in this leaflet.

How much to take

Your doctor will tell you how much of this medicine you should take. This will depend on your condition and whether you are taking any other medicines.

  • Duodenal Ulcers:
    To heal duodenal ulcers the usual adult dose is one 40mg tablet taken at night. To help stop these ulcers coming back the usual dose is one 20mg tablet taken at night.
  • Gastric (Stomach) Ulcers:
    To heal gastric ulcers the usual dose is one 40mg tablet daily, taken at night.
  • Zollinger-Ellison Syndrome:
    Your doctor will determine the dose, depending on how much acid your stomach produces.
  • Gastro-Oesophageal Reflux Disease:
    To treat this, or to help stop it coming back, the usual dose is one 20 mg tablet taken twice daily.

People with kidney problems may need lower doses.

Do not stop taking your medicine or change your dosage without first checking with your doctor or pharmacist.

How to take it

Swallow your tablets whole with a glass of water.

When to take it

If you are taking one dose a day, take the tablet at night. If you are taking two doses a day, take one tablet in the morning and one at night.

Take it at about the same time each day.

Taking your medicine at the same time each day will have the best effect. It will also help you remember when to take it.

It does not matter if you take it before, with or after food.

How long to take it for

Continue taking your medicine for as long as your doctor tells you.

Make sure you have enough to last over weekends and holidays.

For peptic ulcers (ulcers in the stomach or duodenum), you will need to take famotidine tablets for 4 to 8 weeks. Do not stop taking the tablets too early unless your doctor tells you to, as your ulcer may reoccur. To stop duodenal ulcers coming back, you may need more than 8 weeks of treatment.

For the treatment of reflux disease and Zollinger-Ellison Syndrome, you may need to take famotidine tablets for a longer period.

Your doctor will advise you how long to take your tablets for.

If you forget to take it

If it is almost time to take your next dose, skip the missed dose and take your next dose at the usual time. Otherwise, take it as soon as you remember and then go back to taking your medicine as you would normally.

Do not take a double dose to make up for missed doses.

This may increase the chance of you experiencing side effects.

If you have trouble remembering to take your medicine, ask your pharmacist for some hints to help you remember.

If you take too much (overdose)

If you think that you or anyone else may have taken too much of this medicine, immediately telephone your doctor or the Poisons Information Centre (Tel: 13 11 26 in Australia) for advice. Alternatively, go to the Accident and Emergency department at your nearest hospital.

Do this even if there are no signs of discomfort or poisoning. You may need urgent medical attention.

While you are taking this medicine

Things you must do

Tell your doctor that you are taking this medicine if:

  • you are about to be started on any new medicine
  • you are pregnant or are planning to become pregnant
  • you are breastfeeding or are planning to breast-feed
  • you are about to have any blood tests
  • you are going to have surgery or an anaesthetic or are going into hospital

Go to your doctor regularly for a check-up.

Tell any other doctors, dentists and pharmacists who are treating you that you take this medicine.

Things you must not do

Do not:

  • Give this medicine to anyone else, even if their symptoms seem similar to yours.
  • Take your medicine to treat any other condition unless your doctor or pharmacist tells you to.
  • Stop taking your medicine, or change the dosage, without first checking with your doctor.

Things to be careful of

Be careful when driving or operating machinery until you know how this medicine affects you.

Famotidine tablets do not normally cause any problems with your ability to drive a car or operate machinery. However, as with many other medicines, famotidine may cause dizziness in some people. Make sure you know how you react to famotidine before you drive a car or operate machinery.

Things that may help your condition

Some self-help measures suggested below may help your condition. Talk to your doctor or pharmacist about these measures and for more information.

  • Alcohol - your pharmacist or doctor may advise you to limit your alcohol intake.
  • Aspirin and many other medicines used to treat arthritis/period pain/headaches - these medicines may irritate the stomach and may make your condition worse. Your pharmacist or doctor may suggest other medicines you can take.
  • Caffeine - your pharmacist or doctor may advise you to limit the number of drinks which contain caffeine, such as coffee, tea, cocoa and cola drinks, because these contain ingredients that may irritate your stomach.
  • Eating habits - eat smaller, more frequent meals. Eat slowly and chew your food carefully. Try not to rush at meal times.
  • Food - avoid foods that cause you pain or discomfort
  • Smoking - your pharmacist or doctor may advise you to stop smoking or at least cut down on smoking.
  • Weight - your pharmacist or doctor may suggest losing some weight to help your condition.

Possible side effects

Tell your doctor as soon as possible if you do not feel well while you are taking famotidine or if you have any questions or concerns.

Do not be alarmed by the following lists of side effects. You may not experience any of them. All medicines can have side effects. Sometimes they are serious but most of the time they are not.

Tell your doctor if you notice any of the following:

  • headache
  • dizziness
  • diarrhoea, constipation.

Tell your doctor as soon as possible if you notice any of the following.

These may be serious side effects and you may need medical attention:

  • nausea, vomiting, abdominal discomfort or swelling, anorexia, dry mouth
  • fever, fatigue
  • abnormal test results for blood cell levels
  • irregular or rapid heart beat, palpitations
  • muscle pain, cramps, painful joints
  • hallucinations, confusion, agitation, depression, anxiety, inability to sleep, sleepiness, tingling in the fingers or toes, decreased sexual drive, fits
  • breathing difficulties caused by narrowing of the airways, or pneumonia (infection of the lungs)
  • ringing in the ears, taste disorders
  • acne, dry skin, flushing, loss of hair.

If you experience any of the following, stop taking your medicine and contact your doctor immediately or go to the Accident and Emergency department at your nearest hospital.

These are very serious side effects and you may need urgent medical attention or hospitalisation:

  • swelling of the face, lips, mouth or throat which may cause difficulty in swallowing or breathing
  • fluid-filled blisters on the skin or on the lips or genitals or in the eyes, nose or mouth
  • swelling of the hands, feet or ankles
  • any severe skin reaction (skin rash, itchiness, redness, skin ulcers, a scalded appearance)
  • hives or nettle rash (pinkish, itchy swellings on the skin)
  • yellowing of the skin and/or eyes, also called jaundice
  • fits (convulsions), especially in people with kidney problems.

Other side effects not listed above may occur in some patients.

Allergic reactions

If you think you are having an allergic reaction to famotidine, do not take any more of this medicine and tell your doctor immediately or go to the Accident and Emergency department at your nearest hospital.

Symptoms of an allergic reaction may include some or all of the following:

  • cough, shortness of breath, wheezing or difficulty breathing
  • swelling of the face, lips, tongue, throat or other parts of the body
  • rash, itching or hives on the skin
  • fainting
  • hay fever-like symptoms.

Storage and disposal

Storage

Keep your medicine in its original packaging until it is time to take it.

If you take your medicine out of its original packaging it may not keep well.

Keep your medicine in a cool dry place where the temperature will stay below 30°C.

Do not store your medicine, or any other medicine, in the bathroom or near a sink. Do not leave it on a window sill or in the car. Heat and dampness can destroy some medicines.

Keep this medicine where children cannot reach it.

A locked cupboard at least one-and-a-half metres above the ground is a good place to store medicines.

Disposal

If your doctor tells you to stop taking this medicine or it has passed its expiry date, your pharmacist can dispose of the remaining medicine safely.

Product description

What GenRx Famotidine Tablets looks like

  • GenRx Famotidine 20 mg tablets:
    A beige, round, biconvex tablet embossed with 20 on one face and plain on the other.
    Packs of 60 tablets.
  • GenRx Famotidine 40 mg tablets:
    A brown, round, biconvex tablet embossed with 40 on one face and plain on the other.
    Packs of 30 tablets.

* Not all strengths, pack types and/or pack sizes may be available.

Ingredients

Each tablet contains 20 mg or 40 mg of famotidine as the active ingredient.

It also contains the following inactive ingredients:

  • pregelatinised maize starch
  • microcrystalline cellulose
  • magnesium stearate
  • purified talc
  • Opadry™ Buff OY-3690 (20 mg only)
  • Opadry™ Buff OY-3682 (40 mg only).

This medicine is gluten-free, lactose-free, sucrose-free, tartrazine-free and free of other azo dyes.

Australian Registration Numbers

  • GenRx Famotidine 20mg tablets (blister pack):
    AUST R 91513.
  • GenRx Famotidine 40mg tablets (blister pack):
    AUST R 91514.

Sponsor

Apotex Pty Ltd
16 Giffnock Avenue
Macquarie Park NSW 2113

GenRx is a registered trade mark of Apotex Pty Ltd.

This leaflet was last updated in:
May 2013.

BRAND INFORMATION

Brand name

GenRx Famotidine Tablets

Active ingredient

Famotidine

Schedule

S4

 

Name of the medicine

Famotidine.

Excipients.

Pregelatinised maize starch, microcrystalline cellulose, magnesium stearate, purified talc, Opadry Buff OY-3690 (20 mg only) and Opadry Buff OY-3682 (40 mg only).

Description

Chemical name: 3- [[[2-[(aminoiminomethyl) amino]-4-thiazolyl] methyl]thio]- N-(aminosulfonyl) propanimidamide. It is a guanylthiazole derivative. Molecular formula: C8H15N7O2S3. MW: 337.45. CAS: 76824-35-6. Famotidine is a white to pale yellow nonhygroscopic crystalline substance. It is very slightly soluble in water and practically insoluble in ethanol, acetone, ethyl acetate, ether and chloroform. It is freely soluble in glacial acetic acid.
Famotidine is a competitive inhibitor of histamine H2-receptors. The primary clinically important pharmacological activity of famotidine is inhibition of gastric juice secretion. Famotidine reduces the acid and pepsin content, as well as the volume of basal, nocturnal and stimulated gastric secretion.

Pharmacology

Pharmacodynamics.

Gastrointestinal effects.

Famotidine is a competitive inhibitor of histamine H2-receptors. The primary clinically important pharmacological activity of famotidine is inhibition of gastric secretion. Both the acid and pepsin concentration and volume of gastric secretion are suppressed by famotidine, while changes in pepsin secretion are proportional to volume output.
In normal volunteers and hypersecretors, famotidine inhibited basal and nocturnal gastric secretion, as well as secretion stimulated by food and pentagastrin. After oral administration, the onset of the antisecretory effect occurred within one hour; the maximum effect was dose dependent, occurring within one to three hours. Duration of inhibition of secretion by doses of 20 and 40 mg was 10 to 12 hours.
Single evening oral doses of 20 and 40 mg inhibited basal and nocturnal acid secretion in all subjects; mean nocturnal gastric acid secretion was inhibited 86 and 94%, respectively, for a period of at least ten hours. The same doses given in the morning suppressed food stimulated acid secretion in all subjects. The mean suppression was 76 and 84%, respectively, three to five hours after administration, and 25 and 30%, respectively, eight to ten hours after administration. In some subjects who received the 20 mg dose, however, the antisecretory effect was dissipated within six to eight hours. Clinical efficacy studies have not been carried out with a 20 mg dose in acute ulceration. There is no cumulative effect with repeated doses. The nocturnal intragastric pH was raised by evening doses of famotidine 20 and 40 mg to mean values of 5.0 and 6.4, respectively. When famotidine was given after breakfast, the basal daytime interdigestive pH at three and eight hours after famotidine 20 or 40 mg was raised to about 5.
The presence of gastroesophageal reflux disease appears to correlate best with the percentage of time over 24 hours during which the oesophagus is exposed to acid. In patients with gastroesophageal reflux disease, famotidine 20 and 40 mg twice daily reduced intraoesophageal acid exposure into the normal range as measured by 24 hour intraoesophageal pH monitoring. In a clinical study of patients with gastroesophageal reflux disease with endoscopically verified erosive or ulcerative oesophagitis, famotidine 20 and 40 mg twice daily were superior to placebo, and 40 mg twice daily was statistically significantly more effective than 20 mg twice daily in healing oesophageal lesions. In another study, however, the results for the 40 mg twice daily group were similar to the results for the 20 mg twice daily group.
In patients treated for six months with famotidine 20 mg twice daily, relapse of oesophageal erosions or ulceration was significantly less than in patients treated with placebo. Famotidine was also shown to be superior to placebo in preventing symptomatic deterioration.
Famotidine had little or no effect on fasting or postprandial serum gastrin levels. Gastric emptying and exocrine pancreatic function were not affected by famotidine.

Other effects.

Systemic effects of famotidine on the central nervous, cardiovascular, respiratory or endocrine systems have not been found to date. No antiandrogenic effects have been detected.

Pharmacokinetics.

Famotidine is incompletely absorbed. The bioavailability of oral doses is 40 to 45%. Bioavailability may be slightly increased by food, or slightly decreased by antacids; however, these effects are of no clinical consequence. Famotidine undergoes minimal first-pass metabolism. After oral doses, peak plasma levels occur in 1 to 3 hours. Plasma levels after multiple doses are similar to those after single doses. 15 to 20% of famotidine in plasma is protein bound. Famotidine has an elimination half-life of 2.5 to 3.5 hours. Famotidine is eliminated by renal (65 to 70%) and metabolic (30 to 35%) routes. Renal clearance is 250 to 450 mL/min, indicating some tubular excretion. 25 to 30% of an oral dose and 65 to 70% of an intravenous dose are recovered in the urine as unchanged compound. The only metabolite identified in humans is the S-oxide.
There is a close relationship between creatinine clearance values and the elimination half-life of famotidine. In patients with severe renal insufficiency, i.e. creatinine clearance less than 10 mL/min, famotidine elimination half-life may exceed 20 hours and adjustment of dose or dosing intervals in moderate and severe renal insufficiency may be necessary (see Precautions, Dosage and Administration).
Renal excretion increases in a dose dependent linear fashion, but the area under the curve (AUC) and Cmax are not dose proportional. Further studies may be required to define the kinetics of famotidine.
In elderly patients, there are no clinically significant age related changes in the pharmacokinetics of famotidine. However, in elderly patients with decreased renal function, the clearance of the drug may be decreased (see Precautions, Dosage and Administration).

Liver dysfunction.

Hepatic dysfunction does not appear to alter famotidine pharmacokinetics. In a study comparing eleven patients with alcohol related cirrhosis to five healthy control subjects, there were no significant between group differences in famotidine pharmacokinetics following single oral 20 mg doses, single intravenous 20 mg doses or multiple (once daily for seven days) oral 40 mg doses.

Indications

Treatment of duodenal ulcer; benign gastric ulcer; Zollinger-Ellison syndrome; prevention of relapses of duodenal ulceration.
Short-term (no more than 12 weeks) symptomatic relief of gastroesophageal reflux not responsive to conservative measures.
Healing of oesophageal erosion or ulceration associated with gastroesophageal reflux disease.
Prevention of relapses of symptoms and erosions or ulcerations associated with gastroesophageal reflux disease.

Contraindications

Hypersensitivity to any component of these products.
Cross sensitivity in this class of compounds has been observed. Therefore, famotidine should not be administered to patients with a history of hypersensitivity to other H2-receptor antagonists.

Precautions

Community acquired pneumonia.

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 H2-receptor antagonists versus those who had stopped treatment, with an observed adjusted relative risk of 1.63 (95% CI, 1.07-2.48).

Gastric neoplasm.

Gastric malignancy should be excluded prior to initiation of therapy of gastric ulcer with famotidine. Symptomatic response of gastric ulcer to therapy with famotidine does not preclude the presence of gastric malignancy.

Impaired renal function.

CNS adverse effects have been reported in patients with moderate (creatinine clearance < 50 mL/minute) and severe (creatinine clearance < 10 mL/minute) renal insufficiency. Consequently, the famotidine dosage should be reduced in patients with moderate or severe renal insufficiency (see Pharmacology, Dosage and Administration).

Impaired hepatic function.

See Pharmacology, Pharmacokinetics.

Effects on fertility.

In studies with rats given oral doses of up to 2,000 mg/kg/day or intravenous doses of up to 200 mg/kg/day, fertility and reproductive performance were not affected.

Use in pregnancy.

(Category B1)
Famotidine has been demonstrated to cross the placenta and enter the fetus when administered to pregnant rats.
Famotidine has not shown teratogenic effects when given to pregnant rats at doses up to 2,000 mg/kg orally or up to 200 mg/kg intravenously, or in rabbits at oral doses up to 500 mg/kg and 100 mg/kg intravenously.
Famotidine is not recommended for use in pregnancy and should be prescribed only if clearly needed. Before a decision is made to use famotidine during pregnancy, the doctor should weigh the potential benefits from the drug against the possible risks involved.

Use in lactation.

Famotidine is detectable in human milk. Breastfeeding mothers should either stop this drug or stop breastfeeding.

Paediatric use.

Safety and effectiveness of famotidine in children have not been established.

Use in the elderly.

When famotidine was administered to elderly patients in clinical trials, no increase in the incidence or change in the type of adverse effects was observed. No dosage adjustment is required based on age alone. As elderly patients are more likely to have decreased renal function, care should be taken in dose selection in this patient group, and it may be useful to monitor renal function (see Precautions, Impaired renal function and Dosage and Administration).

Carcinogenesis/ mutagenesis.

In a 106 week study in rats and a 92 week study in mice given oral doses of up to 2,000 mg/kg/day (approximately 2,500 times the recommended human dose for active duodenal ulcer), there was no evidence of carcinogenic potential for famotidine.
Famotidine was negative in the microbial mutagen test (Ames test) using Salmonella typhimurium and Escherichia coli with or without rat liver enzyme activation at concentrations up to 10,000 microgram/plate. In in vivo studies in mice with a micronucleus test and a chromosomal aberration test no evidence of a mutagenic effect was observed.

Driving and operating machinery.

Famotidine may cause certain adverse effects such as dizziness, confusion, or hallucinations and therefore, patients should know how they react to famotidine before they operate an automobile or machinery or engage in activities requiring mental alertness and coordination (see Adverse Effects).

Intensive care units.

Agents that elevate gastric pH may increase the already present risk of nosocomial pneumonia in intubated intensive care unit patients receiving mechanical ventilation.

Interactions

No drug interactions of clinical importance have been identified. Famotidine does not interact with the cytochrome P450 linked drug metabolising enzyme system. Compounds metabolised by this system which have been tested in humans in short-term studies include warfarin, propranolol, theophylline, phenytoin, diazepam, aminopyrine and antipyrine. Indocyanine green as an index of hepatic blood flow and/or hepatic drug extraction has been tested and no significant effects have been found.
A study of eleven patients stabilised on phenprocoumon therapy has shown no pharmacokinetic interaction with famotidine and no effect on the pharmacokinetic or anticoagulant activity of phenprocoumon.

Adverse Effects

Famotidine has been shown to be generally well tolerated.
Headache, dizziness, constipation and diarrhoea have been reported at a frequency greater than 1% of patients on therapy with famotidine in controlled clinical trials and may be causally related to famotidine. A similar incidence of the same effects was seen in the placebo or active comparison arms of these studies.
The following other adverse reactions have been reported infrequently in clinical trials or since the drug was marketed. The relationship to therapy with famotidine has been unclear in many cases. Within each category the adverse reactions are listed in order of decreasing severity.

Body as a whole.

Fever, asthenia.

Cardiovascular.

Arrhythmia, atrioventicular block, palpitations.

Hypersensitivity.

Orbital or facial oedema, conjunctival injection.

Musculoskeletal.

Musculoskeletal pain including muscle cramps.

Respiratory.

Bronchospasm.

Dermatological.

Acne, dry skin, flushing.

Special senses.

Tinnitus.
Rarely reported events included dry mouth, nausea and/or vomiting, rash, abdominal discomfort or distension, anorexia, fatigue, pruritus, urticaria, alopecia, liver enzyme abnormalities, hepatitis, cholestatic jaundice, anaphylaxis, angioedema, arthralgia, muscle cramps, taste disorder, reversible psychic disturbances including depression, anxiety disorders, agitation, confusion, hallucinations, thrombocytopenia, leukopenia, neutropenia, and agranulocytosis. Interstitial pneumonia and Stevens-Johnson syndrome/ toxic epidermal necrolysis have been reported very rarely with H2-receptor antagonists. In patients with impaired renal function, the following have been reported very rarely: convulsions, prolonged QT interval.
The following side effects have been reported, however, a causal relationship to therapy with famotidine has not been established: decreased libido, paraesthesia, somnolence, insomnia, grand mal seizure, pancytopenia. Rare cases of impotence and rare cases of gynaecomastia have been reported. However, in controlled clinical trials the incidences were not greater than that seen with placebo.

Dosage and Administration

Duodenal ulcer.

Initial therapy.

The recommended dose of famotidine is one 40 mg tablet daily, taken at night. Treatment should be given for four to eight weeks, but the duration of treatment may be shortened if endoscopy reveals that the ulcer has healed. In most cases, duodenal ulcer healing occurs within four weeks on this regimen. In those patients whose ulcers have not healed completely after four weeks, treatment should be continued for a further four week period.

Maintenance therapy.

For the prevention of recurrence of duodenal ulceration, it is recommended that therapy with famotidine be continued with a dose of one 20 mg tablet daily, taken at night. In ongoing clinical studies this regimen has been continued for 12 months.

Benign gastric ulcer.

The recommended dose of famotidine is one 40 mg tablet daily, taken at night. Treatment should be given for four to eight weeks, but the duration of treatment may be shortened if endoscopy reveals that the ulcer has healed.

Zollinger-Ellison syndrome.

Patients without prior antisecretory therapy should be started on a dose of 20 mg every six hours. Dosage should be adjusted to individual patient needs and should continue for as long as indicated clinically. Doses up to 800 mg daily have been used in a small number of patients for up to one year without the development of significant adverse effects or tachyphylaxis. Patients who have been receiving another H2-antagonist may be switched directly to famotidine at a starting dose higher than that recommended for new cases; this starting dose will depend on the severity of the condition and the last dose of the H2-antagonist previously used.

Gastroesophageal reflux disease.

The recommended dosage for the symptomatic relief of gastroesophageal reflux disease is famotidine 20 mg taken orally twice daily.
For the treatment of oesophageal erosion or ulceration associated with gastroesophageal reflux disease, the recommended dosage is famotidine 20 mg twice daily.

Maintenance therapy.

For the prevention of recurrence of symptoms and erosions or ulcerations associated with gastroesophageal reflux disease, the recommended dosage is famotidine 20 mg twice daily. Efficacy studies have not been conducted beyond six months.

Dosage adjustment for patients with moderate or severe renal insufficiency.

In patients with moderate (creatinine clearance < 50 mL/minute) or severe (creatinine clearance < 10 mL/minute) renal insufficiency, the elimination half-life of famotidine is increased. For patients with severe renal insufficiency it may exceed 20 hours, reaching approximately 24 hours in anuric patients. Since CNS adverse effects have been reported in patients with moderate and severe renal insufficiency, to avoid excess accumulation of the drug in patients with moderate or severe renal insufficiency, the dose of famotidine may be reduced to half the dose or the dosing interval may be prolonged to 36 to 48 hours as indicated by the patient's clinical response.

Overdosage

Symptoms.

The adverse reactions in overdose cases are similar to the adverse reactions encountered in normal clinical experience (see Adverse Effects).
Doses of up to 800 mg daily have been used in a small number of patients with Zollinger-Ellison syndrome for more than a year without development of significant adverse effects.

Treatment.

The usual measures to remove unabsorbed material from the gastrointestinal tract, clinical monitoring and supportive therapy should be employed.
Contact the Poisons Information Centre on 131 126 (Australia) for advice on the management of overdosage.

Presentation

Tablets (round, biconvex, film coated, plain on reverse), 20 mg (beige, marked 20 on one side, AUST R 91513): 60's (blister pack); 40 mg (brown, marked 40 on one side, AUST R 91514): 30's (blister pack).
GenRx Famotidine tablets are intended for oral administration.

Storage

Store below 30°C. Protect from light and moisture.

Poison Schedule

S4.