| Indication |
For the treatment of peptic ulcer disease (PUD) and gastroesophageal reflux disease (GERD). |
| Pharmacodynamics |
Famotidine, a competitive histamine H2-receptor
antagonist, is used to treat gastrointestinal disorders such as gastric
or duodenal ulcer, gastroesophageal reflux disease, and pathological
hypersecretory conditions. Famotidine inhibits many of the isoenzymes of
the hepatic CYP450 enzyme system. Other actions of Famotidine include
an increase in gastric bacterial flora such as nitrate-reducing
organisms. |
| Mechanism of action |
Famotidine binds competitively to H2-receptors located
on the basolateral membrane of the parietal cell, blocking histamine
affects. This competitive inhibition results in reduced basal and
nocturnal gastric acid secretion and a reduction in gastric volume,
acidity, and amount of gastric acid released in response to stimuli
including food, caffeine, insulin, betazole, or pentagastrin. |
| Absorption |
The bioavailability of oral doses is 40-45%. |
| Volume of distribution |
Not Available |
| Protein binding |
15-20% |
| Metabolism |
Hepatic. |
| Route of elimination |
Renal clearance is 250-450 mL/min, indicating some tubular excretion. |
| Half life |
2.5-3.5 hours |
| Clearance |
|
| Toxicity |
Intravenous, mouse: LD50 = 244.4mg/kg; Oral, mouse: LD50
= 4686 mg/kg. Symptoms of overdose include emesis, restlessness, pallor
of mucous membranes or redness of mouth and ears, hypotension,
tachycardia and collapse. |
