Famotidine is prescribed for the short-term treatment of active duodenal ulcer for 4 to 8 weeks and for active, benign gastric ulcer for 6 to 8 weeks. It is prescribed for maintenance therapy, at reduced dosage, after a duodenal ulcer has healed. It is also used for short-term treatment of GERD, a condition in which the acid contents of the stomach flow back into the food canal, and for resulting inflammation of the esophagus. And it is prescribed for certain diseases that cause the stomach to produce excessive quantities of acid, such as Zollinger-Ellison syndrome. Famotidine belongs to a class of drugs known as histamine H2 blockers.
An over-the-counter formulation, Famotidine AC, is used to relieve and prevent heartburn, acid indigestion, and sour stomach.
This drug contains the active ingredient famotidine, which is a type of drug called an H2-receptor antagonist. It works by blocking histamine receptors that are present on cells in the stomach lining.
Normally a substance called histamine binds to these receptors. Histamine is produced throughout the body and has many effects. When histamine binds to H2 receptors on cells in the stomach lining it causes them to produce acid.
Famotidine works by binding to the H2 receptors on the stomach cells, thereby replacing some of the histamine. As a result, the amount of stomach acid produced by these cells is decreased.
Stomach acid is present as a normal part of the digestive process. However, if large amounts of stomach acid are produced, the excess acid may flow back into the food pipe causing pain and a burning sensation known as heartburn or gastro-oesophageal reflux. If severe, it can cause ulceration or erosions in the oesophagus.
In addition, the linings of the stomach and duodenum have a protective layer that normally resists acid attack. If this layer is damaged, or large amounts of stomach acid are produced, a peptic ulcer can develop.
Famotidine decreases the amount of acid in the stomach and duodenum. As a result, it helps relieve gastro-oesophageal reflux, and aids the healing of ulcers. It is also used in various conditions where there is excess acid production in the stomach, eg Zollinger-Ellison syndrome.
Why is this drug prescribed?
- preventing relapse of gastro-oesophageal reflux disease;
- preventing relapse of duodenal ulcers;
- peptic ulcers;
- gastro-oesophageal reflux disease;
- excessive secretion of stomach acid due to a tumour or enlargement of the pancreas;
- skin reactions such as rash and itch;
- muscle cramps;
- loss of appetite;
- jaundice caused by blockage of bile flow;
- headache;
- fatigue;
- dry mouth;
- dizziness;
- disturbances of the gut such as diarrhoea constipation nausea vomiting or abdominal pain;
- depression;
- confusion;
- anxiety and agitation;
- an extreme allergic reaction;
- abnormal enlargement of breasts in men;
- headache;
ADULTS
Duodenal Ulcer
The usual starting dose is 40 mg or 5 ml once a day at bedtime. Results should be seen within 4 weeks, and Famotidine should not be used at full dosage longer than 6 to 8 weeks. Your doctor may have you take 20 mg or 2.5 ml twice a day. The normal maintenance dose after your ulcer has healed is 20 mg or 2.5 ml once a day at bedtime.
Benign Gastric Ulcer
The usual dose is 40 mg or 5 ml once a day at bedtime.
Gastroesophageal Reflux Disease
The usual dose is 20 mg or 2.5 ml twice a day for up to 6 weeks. For inflammation of the esophagus due to GERD, the dose is 20 or 40 mg or 2.5 to 5 ml twice a day for up to 12 weeks.
Excess Acid Conditions
The usual starting dose is 20 mg every 6 hours, although some people need a higher dose. Doses of up to 160 mg every 6 hours have been given in severe cases.
If your kidneys are not functioning properly, your doctor will adjust the dosage.
CHILDREN 1 TO 16 YEARS OLD
Peptic Ulcer
The usual daily dose is 0.5 mg per 2.2 pounds of body weight. The entire dose may be given at bedtime, or divided and given in 2 smaller doses. Do not give more than 40 mg per day.
If your child's kidneys are not functioning properly, your doctor will adjust the dosage.
Gastroesophageal Reflux Disease
The usual daily dose is 1 mg per 2.2 pounds of body weight, divided and given in 2 smaller doses. Do not exceed 40 mg daily.
If your child's kidneys are not functioning properly, your doctor will adjust the dosage.
INFANTS UNDER 12 MONTHS OLD
Gastroesophageal Reflux Disease
The usual starting dose of the oral suspension is 0.5 mg per 2.2 pounds of body weight once a day for infants under 3 months and twice a day for infants 3 to 11 months. The dosage can be given for up to 8 weeks. Your doctor may also recommend additional measures to relieve the symptoms, such as thickening the child's food.
If your child's kidneys are not functioning properly, your doctor will adjust the dosage.
Famotidine AC
Do not give Famotidine AC to children under 12 years old unless your doctor approves. Swallow tablets or gelcaps with a glass of water. Chew the chewable tablets completely; do not swallow them whole. Do not take more than 2 pills a day or take them for longer than 2 weeks unless your doctor approves.
For Prevention
Take 1 tablet, gelcap, or chewable tablet 15 minutes or more before eating a meal that could cause heartburn.
For Relief
Take 1 tablet, gelcap, or chewable tablet.
