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Famotidine Description
Famotidine 20 mg and 40 mg Tablet : Square, light orange film-coated tablet,
bevel-edged with shallow convex faces.
Composition
Famotidine 20 mg/tablet
Famotidine 40 mg/tablet
Action & Pharmacology
Famotidine is a H2-receptor antagonist. It inhibits basal and
nocturnal gastric acid secretion by competitive inhibition of the action of
histamine at the histamine H, receptors of the parietal cells. It also
inhibits gastric acid secretion stimulated by food, betazole, pentagastrin,
caffeine, insulin and physiological vagal reflex. It is rapidly but
incompletely absorbed from the gastro-intestinal tract. Most is excreted
unchanged in urine.
Indications
Famotidine is indicated in the short term treatment of duodenal ulcer,
benign gastric ulcer and hypersecretory conditions such as Zollinger-Ellison
syndrome. It is also used in the prevention of relapses of duodenal
ulceration, symptomatic relief of gastrooesophageal reflux disease and
healing of oesophageal erosions or ulceration associated with gastro-oesophageal
reflux disease.
Contraindications
Risk-benefit should be considered when the following medical problems exist:
- Cirrhosis
- Hepatic and renal function impairment
- Sensitivity to any of the histamine H2-receptor antagonists
Precautions
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- Patients with moderate
or severe renal insufficiency features |
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Since CNS adverse effects
have been reported in patients with moderate and severe renal
insufficiency, longer intervals between doses or lower doses may
need to be used in patients with moderate (creatinine clearance <
50mL/min) or severe (creatinine clearance < 10mL/min) renal
insufficiency to adjust for the longer elimination half-life of
tamotidine |
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- Patients with Gastric
Ulcer: |
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Before giving tamotidine
to patients with gastric ulcers, the possibility of malignancy
should be excluded since famotidine may mask symptoms and delay
diagnosis. It should be given in reduced dosage to patients with
impaired renal function. |
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- Pregnancy and Lactation |
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It is not recommended for
use in pregnancy and should be prescribed only if clearly needed and
the physician should again weigh the potential benefits from the
drug against the possible risks. Famotidine is secreted in human
milk, therefore breast-feeding mothers should either stop
breast-feeding or stop taking the drug. |
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- Paediatric use |
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Safety and effectiveness
of famotidine in children have not been established. |
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- Geriatric use |
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As elderly patients are
more likely to have decreased clearance of tamotidine, care should
be taken in dose selection and it may be useful to monitor renal
function. |
Main Side/Adverse Effects
Headache, drowsiness, nausea and vomiting, loss of appetite, diarrhoea,
constipation, dryness of mouth and skin, skin rash, loss of hair, joint or
muscle pain and confusion. Famotidine is reported to have little or no
androgenic effects, although there are isolated reports of gynaecomastia and
impotence.
Overdosage
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Clinical features: |
Experience with overdose
in humans is limited. Toxic doses of tamotidine given intravenously
to dogs caused emesis, restlessness, pallor of mucous membranes or
redness of mouth and ears, skin rash. |
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Treatment: |
Since there is no
specific antidote for overdose, treatment is symptomatic and
supportive with possible utilization of the following :
- Induction of emesis and/or use of gastric lavage.
- For seizures, treatment with intravenous diazepam.
- For bradycardia, treatment with atropine.
- For ventricular arrhythmias, treatment with lidocaine.
- Possible laboratory monitoring for adverse reactions. |
Drug Interactions
- Clinical experience with famotidine is very limited.
- Simultaneous administration of antacids is not recommended since
absorption of famotidine may be decreased; patients should be advised not to
take any antacids within
½ to 1 hour of histamine H2-receptor antagonists.
- Concurrent use with bone marrow
depressants may increase the risk of neutropenia or other blood dyscrasias.
- Concurrent administration of ketoconazole may result in a marked reduction
in absorption of ketoconazole; patients should be advised to take tamotidine
at least 2 hours after ketoconazole.
Dosage & Administration
Usual adult and adolescent dose:
Duodenal ulcer:
Treatment: Oral, 40 mg once daily at bedtime or 20 mg 2 times daily.
Prophylaxis of recurrent duodenal
ulcer : Oral, 20 mg at bedtime.
Gastric ulcer:
Oral, 40 mg once daily at bedtime.
Gastric hypersecretory conditions leg. Zollinger-Ellison syndrome):
Oral, 20 mg every 6 hours, the dosage being adjusted as needed and therapy
continued for as long as clinically indicated. Doses up to 160 mg every 6
hours have been administered to some patients with severe Zollinger-Ellison
syndrome.
Gastro-oesophageal reflux:
Oral, 20 mg 2 times daily for up to 6 weeks.
The recommended oral dose for oesophagitis due to gastro-oesophageal reflux
disease is 20 to 40 mg 2 times daily for up to 12 weeks.
Dosage Adjustment for patients with moderate of severe renal insufficiency:
In adult patients with moderate (creatinine clearance < 50 mL/min) or severe
(creatinine clearance < 10mL/min) renal insufficiency, the dose of
Famotidine may be reduced to halt the dose or the dosing interval may be
prolonged to 36-48 hours as indicated by patient's clinical response.
Note : The information given here is limited. For further information,
please consult your doctor or pharmacist.
Storage
Store below 25°C. Protect from
light and moisture.
Shelf-life
3 years from date of manufacture.
Presentation/Packing
Film-coated tablet 20 mg x
1000's, Blisters of 10 x 10's
Film-coated tablet 40 mg x 1000's, Blisters of 10 x 10's |
