Consumer medicine information

Ausfam

Famotidine

BRAND INFORMATION

Brand name

Ausfam

Active ingredient

Famotidine

Schedule

S4

 

Consumer medicine information (CMI) leaflet

Please read this leaflet carefully before you start using Ausfam.

What is in this leaflet

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

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

If you have any concerns about taking this medicine, talk to your doctor or pharmacist.

Keep this leaflet with your medicine.

You may need to read it again.

What AUSFAM is used for

AUSFAM is used to:

  • treat peptic ulcers (gastric and duodenal ulcers)
  • treat reflux oesophagitis (reflux disease)
  • treat a rare condition called Zollinger-Ellison syndrome
  • prevent duodenal ulcers and reflux disease from coming back.

Peptic ulcers:
AUSFAM is used to heal peptic ulcers. Depending on the position of the ulcer it is called a gastric or duodenal ulcer. A gastric ulcer occurs in the stomach. A duodenal ulcer occurs in the duodenum, which is the tube leading out of the stomach. These ulcers usually cause pain and discomfort (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.

AUSFAM is also used to help stop duodenal ulcers from coming back.

Reflux disease:
AUSFAM is used to treat reflux oesophagitis, also called reflux disease, and stop it from coming back. This condition is caused by the washing back, or reflux, of food and acid from the stomach into the food pipe, also called the oesophagus. This causes a painful burning sensation in the chest rising up to the throat (heartburn), and usually occurs after eating or at night.

Zollinger-Ellison syndrome:
AUSFAM is used to treat a rare condition called Zollinger-Ellison syndrome, where the stomach produces very large amounts of acid, much more than in ulcers and reflux disease.

AUSFAM belongs to a group of medicines called histamine H2-antagonists. These medicines work by reducing the amount of acid made by the stomach. This helps reduce the pain and also allows the ulcer and/or reflux disease to heal in most people.

Your doctor may have prescribed this medicine for another reason.

Ask your doctor if you have any questions about why it has been prescribed for you.

AUSFAM is not recommended for use in children, as the safety and effectiveness of this drug have not been established in children.

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

There is no evidence that it is addictive.

Before you take it

When you must not take it

Do not take AUSFAM if you are allergic to:

  • medicines containing famotidine
  • any other histamine H2-antagonist medicine
  • any of the ingredients listed at the end of this leaflet.

Some of the symptoms of an allergic reaction may include skin rash, itchiness or hives, swelling of the face, lips or tongue (which may cause difficulty in swallowing), shortness of breath, wheezing or difficulty breathing.

Do not take AUSFAM if you are breastfeeding. This medicine passes into breast milk and may affect your baby.

Do not take it if the expiry date (Exp.) printed on the pack has passed. If you take this medicine after the expiry date has passed, it may not work as well.

Do not take AUSFAM if the packaging shows signs of tampering or the tablets do not look quite right.

Before you start to take it

Tell your doctor if you are allergic to any other medicines, foods, dyes or preservatives.

Tell your doctor if you are pregnant or plan to become pregnant. Your doctor will discuss the risks and benefits of taking AUSFAM during pregnancy.

Tell your doctor if you have kidney problems or any other medical conditions.

If you have not told your doctor about any of the above, tell them before you start taking AUSFAM.

Taking other medicines

Tell your doctor if you are taking any other medicines, including any that you buy without a prescription from a pharmacy, supermarket or health food shop.

Some medicines may affect the way other medicines work. However, AUSFAM has not been shown to interfere with other medicines.

How to take it

How much to take

Your doctor will tell you how many tablets you need to take each day and when to take them. This depends on your condition.

To heal peptic ulcers, the usual dose is one 40 mg tablet taken at night.

To help stop duodenal ulcers from coming back, the usual dose is one 20 mg tablet taken at night.

For Zollinger-Ellison syndrome the dose depends on how much acid your stomach is producing. Your doctor will decide how much you need to take.

The usual dose for the treatment and maintenance of reflux disease is one 20 mg tablet taken twice a day.

If you have kidney disease, the doctor may prescribe a lower dose.

Follow all directions given to you by your doctor and pharmacist carefully.

If you forget to take it

If it is almost time for your next dose, skip the dose you missed and take your next dose when you are meant to.

Otherwise, take the missed dose as soon as you remember, and then go back to taking your tablets as you would normally.

Do not take two doses at a time to make up for the dose you missed.

If you are not sure what to do, ask your doctor or pharmacist.

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 dose in the morning and one at night.

AUSFAM can be taken with or without food.

Swallow it with a glass of water.

How long to take it for

For peptic ulcers, AUSFAM needs to be taken for 4 to 8 weeks.

Do not stop taking AUSFAM, even if you feel better unless advised by your doctor. Stopping your tablets too early may let the ulcer come back.

Sometimes you need more than 8 weeks of treatment with AUSFAM to stop the ulcer from coming back. Your doctor will decide if you need to continue treatment.

For the treatment of reflux disease and Zollinger-Ellison syndrome, you usually need to take AUSFAM for longer. Your doctor will let you know how long to keep taking the tablets.

Keep taking AUSFAM for as long as your doctor recommends.

If you take too much (overdose)

Immediately telephone your doctor, or the Poisons Information Centre (telephone 13 11 26), or go to Accident and Emergency at the nearest hospital, if you think you or anyone else may have taken too much AUSFAM. Do this even if there are no signs of discomfort or poisoning.

While you are taking it

Things you must do

Before starting any new medicine, tell your doctor or pharmacist that you are taking AUSFAM.

Tell all the doctors, dentists and pharmacists who are treating you that you are taking AUSFAM.

If you become pregnant while taking this medicine, tell your doctor.

If you develop sudden onset of fever, rigors and shortness of breath, and/or a dry cough that becomes productive with ‘rusty’ and green sputum, tell your doctor immediately.

Visit your doctor regularly so they can check on your progress.

Things you must not do

Do not use this medicine to treat any other conditions unless your doctor tells you to.

Do not give it to anyone else, even if they have the same condition as you.

Things to be careful of

Be careful driving or operating machinery until you know how AUSFAM affects you. It generally does not cause any problems with your ability to drive a car or operate machinery. However, as with many other medicines, AUSFAM may cause dizziness, headache, confusion or hallucination in some people. Patients should be informed that they should avoid driving vehicles or operating machinery or doing activities which require prompt vigilance if they experience these symptoms.

Suggestions that may help your condition

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

  • Alcohol – your doctor may advise you to limit your alcohol intake
  • Aspirin and many other medicines used to treat arthritis/period pain or headache – these medicines may irritate the stomach and make your condition worse. Your doctor or pharmacist may suggest other medicines you can take
  • Caffeine – your 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 doctor or pharmacist may advise you to stop smoking or at least cut down.

Side effects

Tell your doctor or pharmacist as soon as possible if you do not feel well while you are taking AUSFAM.

Like all other medicines, AUSFAM may have unwanted side effects in some people. Sometimes they are serious, most of the time they are not. You may need medical treatment if you get some of the side effects.

Ask your doctor or pharmacist to answer any questions you may have.

Tell your doctor if you notice any of the following and they worry you:

  • headache
  • dizziness
  • diarrhoea, constipation.

These are generally mild side effects.

If any of the following happen, stop taking AUSFAM and tell your doctor immediately, or go to Accident and Emergency at the nearest hospital:

  • swelling of the face, lips mouth or throat which may cause difficulty in swallowing or breathing
  • swelling of the hands, feet or ankles
  • any severe skin reaction
  • hives or nettlerash (pinkish, itchy swellings on the skin)
  • yellowing of the skin and/or eyes (jaundice).

These are serious but rare side effects.

Other side effects not listed above may also occur in some patients. Tell your doctor if you notice anything that is making you feel unwell.

After using it

Storage

Keep your 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.

Keep your tablets in the pack until it is time to take them. If you take the tablets out of the blister pack they may not keep well.

Keep your tablets in a cool dry place where the temperature stays below 30°C.

Do not store AUSFAM or any other medicine in the bathroom or near a sink.

Do not leave AUSFAM in the car or on window sills. Heat and dampness can destroy some medicines.

Disposal

If your doctor tells you to stop taking AUSFAM, or your tablets have passed their expiry date, ask your pharmacist what to do with any that are left over.

Product description

What it looks like

AUSFAM comes in 2 strengths of tablets:

  • AUSFAM 20 – square, tan tablet marked “FO over 20” on one side and plain on the other side. Each blister pack contains 60 tablets.
  • AUSFAM 40 – square, brown tablet marked “FO over 40” on one side and plain on the other side. Each blister pack contains 30 tablets.

Ingredients

The active ingredient in AUSFAM is famotidine.

  • each AUSFAM 20 tablet contains 20 mg of famotidine
  • each AUSFAM 40 tablet contains 40 mg of famotidine.

The tablets also contain:

  • microcrystalline cellulose
  • pregelatinised maize starch
  • purified talc
  • magnesium stearate
  • Opadry Brown 03B56615 (20 mg tablets)
  • Opadry Brown 03B56611 (40 mg tablets).

The tablets are gluten free.

Manufacturer

Arrotex Pharmaceuticals Pty Ltd
15 – 17 Chapel Street
Cremorne VIC 3121

Australian registration numbers:

AUSFAM 20 - Aust R 93788
AUSFAM 40 - Aust R 93789

This leaflet was revised in September 2023

Published by MIMS October 2023

BRAND INFORMATION

Brand name

Ausfam

Active ingredient

Famotidine

Schedule

S4

 

1 Name of Medicine

Famotidine.

2 Qualitative and Quantitative Composition

Ausfam tablets come in two strengths and contain either 20 mg or 40 mg of famotidine.
For the full list of excipients, see Section 6.1 List of Excipients.

3 Pharmaceutical Form

Ausfam 20.

20 mg tablet: tan, square, marked "FO over 20" on one side and plain on the other side.

Ausfam 40.

40 mg tablet: brown, square, marked "FO over 40" on one side and plain on the other side.

4 Clinical Particulars

4.1 Therapeutic Indications

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.

4.2 Dose and Method of 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 of 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 these patients, the dose of famotidine may be reduced to half the normal dose or the dosing interval may be prolonged to 36 to 48 hours as indicated by the patient's clinical response.

4.3 Contraindications

Hypersensitivity to famotidine or any other 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 histamine H2-receptor antagonists.
For administration to breastfeeding women (see Section 4.6 Fertility, Pregnancy and Lactation).

4.4 Special Warnings and Precautions for Use

Identified precautions.

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.
Do not administer famotidine tablets in cases of minor gastrointestinal complaints.
In patients with duodenal ulcers and benign gastric ulcers, the H. pylori status should be determined. Wherever possible, patients with H. pylori should undergo eradication therapy to eliminate the bacteria.

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.

General.

In case of long-term treatment with high dosage, monitoring of blood count and liver function is recommended.
In case of long-standing ulcer disease, abrupt withdrawal after symptom relief should be avoided.

Use in hepatic impairment.

Impaired hepatic function.

See Section 5.2 Pharmacokinetic Properties.

Use in renal impairment.

Impaired renal function.

Central nervous system 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 Section 5 Pharmacological Properties; Section 4.2 Dose and Method of Administration).

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 Section 4.4 Special Warnings and Precautions for Use, Use in renal impairment; Section 4.2 Dose and Method of Administration).

Paediatric use.

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

Effects on laboratory tests.

Laboratory parameters may be affected during treatment with famotidine, but the changes are usually not considered serious. Among the laboratory changes that were reported during clinical trials were increases in AST, ALT, BUN, and serum creatinine. These changes were rarely of clinical significance. Only three patients had to be discontinued from therapy because of laboratory adverse experiences, however laboratory abnormalities were present at baseline.

4.5 Interactions with Other Medicines and Other Forms of Interactions

During concomitant use of drugs where the absorption of the drug is affected by the amount of gastric juice, a possible effect on the absorption should be taken into consideration. The absorption of ketoconazole and itraconazole could be reduced. Ketoconazole should be given two hours before famotidine administration.
Probenecid inhibits renal tubular secretion of famotidine, and has been shown to cause an increase in plasma levels of famotidine. Therefore, concomitant use of probenecid and famotidine should be avoided.
Concomitant use of famotidine and antacids could reduce the famotidine uptake and cause lower plasma levels of famotidine. Therefore, famotidine should be administered 1-2 hours before antacids.
Concomitant use of sucralfate inhibits absorption of famotidine. Therefore, sucralfate should not be administered after famotidine.
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.
In addition, studies with famotidine have shown no augmentation of expected blood alcohol levels resulting from alcohol ingestion.
Alterations of gastric pH may affect the bioavailability of certain drugs resulting in a decrease in the absorption of atazanavir.
Risk of loss of efficacy of calcium carbonate when co-administered as phosphate binder with famotidine in hemodialysis patients.
Co-administration of posaconazole oral-suspension with famotidine should be avoided, if possible, since famotidine may reduce the absorption of posaconazole oral-suspension during concomitant use.
Co-administration of famotidine with the tyrosine kinase inhibitors (TKIs) dasatinib, erlotinib, gefitinib, pazopanib may decrease plasma concentrations of TKIs resulting in lower efficacy, therefore co-administration of famotidine with these TKIs is not recommended. For further specific recommendations please refer to the product information of individual TKI medicinal products.

4.6 Fertility, Pregnancy and Lactation

Effects on fertility.

Famotidine did not appear to affect the fertility of rats at oral doses up to 2,000 mg/kg or intravenous doses up to 200 mg/kg.
(Category B1)
Famotidine has been demonstrated to cross the placenta and enter the foetus 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.
 Famotidine is detectable in human milk. Breastfeeding women should either stop this drug or stop breastfeeding.

4.7 Effects on Ability to Drive and Use Machines

Some patients have experienced adverse reactions such as dizziness, headache, confusion or hallucinations while taking famotidine. Patients should be informed that they should avoid driving vehicles or operating machinery or doing activities which require prompt vigilance if they experience these symptoms.

4.8 Adverse Effects (Undesirable Effects)

Famotidine has been shown to be generally well tolerated. Headache, dizziness, constipation and diarrhoea have been reported at a frequency of greater than 1% 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.
[Very common (> 1/10); common (> 1/100, < 1/10); uncommon (> 1/1000, <1/100); rare (> 1/10,000, < 1/1,000); very rare (< 1/10,000) including isolated cases; not known (cannot be estimated from the available data)].

Blood and the lymphatic system disorders.

Very rare: thrombocytopenia, leukopenia, agranulocytosis, pancytopenia, neutropenia.

Psychiatric disorders.

Rare: reversible psychological disturbances including hallucinations, confusion, anxiety disorders, agitation, depression.
Very rare: disorientation, reduced libido, insomnia.

Nervous system disorders.

Common: headache, dizziness.
Uncommon: taste disorder.
Very rare: paraesthesia; somnolence; epileptic seizures, convulsions; grand mal seizures (particularly in patients with impaired renal function).

Gastrointestinal disorders.

Common: constipation, diarrhoea.
Uncommon: nausea, vomiting, abdominal discomfort or distension, flatulence, dry mouth.

Hepatobiliary disorders.

Rare: intrahepatic cholestasis (visible sign: jaundice), hepatitis, cholestatic jaundice, increase in liver enzyme abnormalities (transaminases, gamma GT, alkaline phosphatase, bilirubin), isolated cases of worsening of existing hepatic disease.

Metabolism and nutrition disorders.

Uncommon: loss of appetite (anorexia).

Skin and subcutaneous tissue disorders.

Uncommon: rash, pruritus, urticaria, acne, dry skin, flushing.
Very rare: alopecia, Stevens-Johnson syndrome/toxic epidermal necrolysis sometimes fatal.

Immune system disorders.

Rare: anaphylaxis.
Very rare: hypersensitivity reactions (angioneurotic oedema, bronchospasm).

Respiratory, thoracic and mediastinal disorders.

Very rare: interstitial pneumonia sometimes fatal.

Musculoskeletal, connective tissue and bone disorders.

Rare: muscle cramps, arthralgia.

Cardiac disorders.

Very rare: AV block with H2 receptor antagonists administered intravenously, palpitations, arrhythmias, QT prolongation (especially in patients with impaired renal function).

General disorders and administration site conditions.

Uncommon: fatigue.
Very rare: chest tightness, fever, tinnitus, orbital oedema.
Rare: angioedema.

Reproductive system and breast disorders.

Very rare: impotence.
Rare: gynaecomastia.
In patients with impaired renal function, the following have been reported very rarely: convulsions, prolonged QT interval. As with other H2-receptor antagonists, cases of bradycardia, A-V block and other arrhythmias have been reported rarely in patients treated with famotidine.

Reporting suspected adverse effects.

Reporting suspected adverse reactions after registration of the medicinal product is important. It allows continued monitoring of the benefit-risk balance of the medicinal product. Healthcare professionals are asked to report any suspected adverse reactions at www.tga.gov.au/reporting-problems.

4.9 Overdose

There is no experience to date with overdosage. 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. The usual measures to remove unabsorbed material from the gastrointestinal tract, clinical monitoring and supportive therapy should be employed.
For information on the management of overdose, contact the Poisons Information Centre on 13 11 26 (Australia).

5 Pharmacological Properties

5.1 Pharmacodynamic Properties

Mechanism of action.

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 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 by 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 was 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 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.

Other effects.

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

Clinical trials.

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.

5.2 Pharmacokinetic Properties

Absorption.

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.

Distribution.

15 to 20% of famotidine in plasma is protein bound.

Metabolism.

Famotidine undergoes minimal first pass metabolism. After oral doses, peak plasma levels occur in one to six hours. Plasma levels after multiple doses are similar to those after single doses.

Excretion.

Famotidine has an elimination half-life of 2.5 to 5 hours. Famotidine is eliminated by renal (65 to 70%) and metabolic (30 to 35%) routes. Renal clearance is 250 to 450 mL/minute, indicating some tubular excretion. 25 to 30% of an oral dose is 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/minute, 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 Section 4.4 Special Warnings and Precautions for Use; Section 4.2 Dose and Method of 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.

Elderly.

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 Section 4.4 Special Warnings and Precautions for Use; Section 4.2 Dose and Method of 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 or multiple (once daily for seven days) oral 40 mg doses.

5.3 Preclinical Safety Data

Genotoxicity.

No data available.

Carcinogenicity.

No data available.

6 Pharmaceutical Particulars

6.1 List of Excipients

Ausfam tablets also contain the following excipients: microcrystalline cellulose, pregelatinised maize starch, purified talc, magnesium stearate, Opadry brown 03B56615 (20 mg only) and Opadry brown O3B56611 (40 mg only). The tablets are gluten free.

6.2 Incompatibilities

Incompatibilities were either not assessed or not identified as part of the registration of this medicine.

6.3 Shelf Life

In Australia, information on the shelf life can be found on the public summary of the Australian Register of Therapeutic Goods (ARTG). The expiry date can be found on the packaging.

6.4 Special Precautions for Storage

Store the tablets in a dry place below 30°C.

6.5 Nature and Contents of Container

Ausfam 20 mg tablet available in blister packs (PVC/PVDC/Al) of 60 tablets.
Ausfam 40 mg tablet available in blister packs (PVC/PVDC/Al) of 30 tablets.

6.6 Special Precautions for Disposal

In Australia, any unused medicine or waste material should be disposed of by taking to your local pharmacy.

6.7 Physicochemical Properties

Famotidine is a white or yellowish-white, crystalline powder or crystals which is very slightly soluble in water, freely soluble in dimethylformamide and in glacial acetic acid, slightly soluble in methanol, very slightly soluble in ethanol, practically insoluble in ether and in ethyl acetate. It dissolves in dilute mineral acids.
The chemical name for famotidine is N2-(aminosulphonyl)-3-[[[2-[(diamino methylene) amino]thiazol-4yl]methyl] thio] propanamidine. Its structural formula is:

Chemical structure.


C8H15N7O2S3.
Molecular weight: 337.4.

CAS number.

76824-35-6.

7 Medicine Schedule (Poisons Standard)

S4 - Prescription only medicine.

Summary Table of Changes