|
Voker
Famotidine, the active ingredient
of Voker F. C. Tablet, is a histamine H2-receptor antagonist. Chemically,
famotidine is
3-[2(diaminomethyleneamino)thiazol-4-ylmethylthiol]-N-sulphamoyl-propionamidine.
Ingredient(s)
Voker F. C. Tablet 20mg
Each tablet contains: Famotidine ............. 20mg
Voker F. C. Tablet 40mg
Each tablet contains: Famotidine ..............40mg
Pharmacology (Summary of Pharmacodynamic and Pharmacokinetics)
1. Famotidine is a potent inhibitor of gastric acid secretion acting at the
H2-receptor site. It is a competitive antagonist with high selectivity and
binding affinity.
2. Basal acid output is diminished, as is maximal acid output stimulated by
pentagastrin or food. In addition to the reduction in acid output, the
volume of gastric secretion is decreased in basal, nocturnal and stimulated
states.
3. Famotidine is 40 times as potent as cimetidine with a duration of action
1 ~ 3 times as long. Famotidine has 7 ~10 times the potency of ranitidine.
40mg of famotidine is roughly equivalent to 300mg of ranitidine in reducing
basal and nocturnal acid secretion by at least 75% for up to 12 hours. The
duration of acid suppression with famotidine is longer than that with
ranitidine.
4. Famotidine has no anti-androgenic activity and has no effects on hepatic
cytochrome P450 activity.
5. In normal subjects, 20mg of famotidine suppressed pentagastrinstimulated
acid output by 90%, two hours after oral administration; at 12 hours, output
was still only 50% of control. A 10mg dose suppressed acid output by 70%,
and 5mg by 60% at 2 hours. Famotidine is considerably more potent than
cimetidine, the inhibitory effect of 5mg famotidine were comparable to 300mg
of cimetidine.
6. After oral administration, absorption is rapid and the onset of action is
by one hour, approximately 40% of an oral dose is absorbed. Peak plasma
concentrations occur about 2 hours after dosing.
7. Famotidine has minimal pre-systemic metabolism. 15 ~ 20% of the drug is
bound to plasma proteins. The plasma half-life of the drug is approximately
3 hours, but the duration of action is longer.
8. Famotidine is excreted in the urine largely unchanged, and this
represents that major mode of elimination of the drug.
Indication(s)
For the treatment of benign gastric and duodenal ulcers, reflux oesophagitis
and Zollinger-Ellison Syndrome.
Dosage and Administration
Duodenal and benign gastric ulcer: Initial daily dosage is 40mg at bedtime
for up to 4 ~ 8 weeks, maintenance: 20mg at night time.
Zollinger-Ellison Syndrome
initially 20mg every 6 hours; maximum of 800mg daily. Reflux oesophagitis:
20 to 40mg twice daily for 6 to 12 weeks.
Dosage adjustment is required for patients with moderate to severe renal
insufficiency.
Since CNS adverse effects have been reported in patients with moderate to
severe renal insufficiency, to avoid excess accumulation of the drug, the
dose of famotidine may be reduced to half the recommended dose or the dosing
interval may be prolonged to 36-48 hours as indicated by the patient's
clinical response.
Contraindication(s)
Hypersensitivity to any component of this product.
Precaution(s)/Warning(s)
1. Symptomatic response to therapy with Famotidine does not preclude the
presence of gastric malignancy.
2. For patients with severe renal
insufficiency ( creatinine clearance rates below 10ml/min ), the dose should
be reduced to 20mg nocte to compensate for the slower elimination of the
drug.
3. There are no adequate or well-controlled studies in pregnant women, this
drug should be used during pregnancy only if clearly needed.
4. Studies performed in lactating
rats have shown that Famotidine is secreted into breast milk. A decision
should be made whether to discontinue nursing or discontinue the drug,
taking into account the importance of the drug to the mother.
5. Pediatric Use: Safety and
effectiveness in children have not been established.
6. As elderly patients are more
likely to have decreased clearance of famotidine, care should be taken in
dose selection and it may be useful to monitor renal function.
Drug Interaction(s)
No drug interactions of clinical importance have been identified. Voker does
not interact with the cytochrome P450-linked drug metabolizing enzyme
system. Compounds metabolized by this system which have been tested in man
include warfarin, theophylline, phenytoin, diazepam, propranolol,
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.
Studies in patient stabilized on
phenprocoumon therapy have shown no pharmacokinetic interaction with
famotidine and no effect on the pharmacokinetic on anticoagulant activity of
phenprocoumon.
Side Effect(s) / Adverse
Reaction(s)
Gastrointestinal : Constipation, diarrhea, vomiting, abdominal discomfort,
anorexia, dry mouth, liver enzyme abnormalities.
Nervous System : headache, dizziness, psychic disturbances. Cardiovascular :
palpitations, arrhythmia, AV block
Respiratory : bronchospasm
Body as a whole : fever, asthenia, fatigue
Skin : pruritus, dry skin, flushing, acne
Special senses : tinnitus, taste disorders.
Symptoms and Treatment for Overdosage, and Antidote(s)
There is no experience to date
with deliberate overdosage. Signs of acute intoxication in I.V. treated dogs
were emesis, restlessness, tachycardia and collapse.
Doses of up to 640mg/day have been given to patients with pathological
hypersecretory condition with no serious adverse effects. In the event of
overdosage, treatment should be symptomatic and supportive. Unabsorbed
material should be removed from the gastrointestinal tract, the patients
should be monitored, and supportive therapy should be employed.
Shelf-Life
3 years from the date of manufacture.
Storage Condition(s)
Keep in a tight container. Store at temperature below 30°C. Protect from
light and moisture.
Product Description and Packing(s)
Voker F. C. Tablet 20mg:
An orange film coated square tablet.
Blister packing of 10's x 6, 10's x 10 and 10's x 50.
Plastic bottle of 1000's (for
export only).
Voker F. C. Tablet 40mg:
An orange film coated tablet, one side with a-score.
Blister packing of 10's x 6, 10's
x 10 and 10's x 50.
Plastic bottle of 1000's (for
export only).
|
