Tagamet is a histamine H2-receptor antagonist which rapidly inhibits both basal and stimulated gastric secretion of acid and reduces pepsin output.
Tagamet is indicated in the treatment of duodenal and benign gastric ulceration, including that associated with non-steroidal anti-inflammatory agents, recurrent and stomal ulceration, oesophageal reflux disease and other conditions where reduction of gastric acid by Tagamet has been shown to be beneficial: persistent dyspeptic symptoms with or without ulceration, particularly meal-related upper abdominal pain, including such symptoms associated with non-steroidal anti-inflammatory agents; the prophylaxis of gastrointestinal haemorrhage from stress ulceration in critically ill patients; before general anaesthesia in patients thought to be at risk of acid aspiration (Mendelson’s) syndrome, particularly obstetric patients during labour; to reduce malabsorption and fluid loss in the short bowel syndrome; and in pancreatic insufficiency to reduce degradation of enzyme supplements. Tagamet is also recommended in the management of the Zollinger-Ellison syndrome.
The total daily dose should not normally exceed 2.4g. Dosage should be reduced in patients with impaired renal function (see Section 4.4).
The usual dosage is 400mg twice a day with breakfast and at bedtime. Alternatively for patients with duodenal or benign gastric ulceration, a single daily dose of 800mg at bedtime can be used. Other effective regimens are 200mg three times a day with meals and 400mg at bedtime (1.0g/day) and, if inadequate, 400mg four times a day (1.6g/day) also with meals and at bedtime.
Treatment should be given initially for at least four weeks (six weeks in benign gastric ulcer eight weeks in ulcer associated with continued non-steroidal anti-inflammatory agents) even if symptomatic relief has been achieved sooner. Most ulcers will have healed by that stage, but those which have not will usually do so after a further course of treatment.
Treatment may be continued for longer periods in those patients who may benefit from reduction of gastric secretion and the dosage may be reduced in those who have responded to treatment, for example to 400mg at bedtime or 400mg in the morning and at bedtime.
In patients with benign peptic ulcer disease who have responded to the initial course, relapse may be prevented by continued treatment, usually with 400mg at bedtime; 400mg in the morning and at bedtime has also been used.
In oesophageal reflux disease, 400mg four times a day, with meals and at bedtime, for four to eight weeks is recommended to heal oesophagitis and relieve associated symptoms.
In patients with very high gastric acid secretion (e.g. Zollinger-Ellison syndrome) it may be necessary to increase the dose to 400mg four times a day, or in occasional cases further.
Antacids can be made available to all patients until symptoms disappear.
In the prophylaxis of haemorrhage from stress ulceration in seriously ill patients, doses of 200-400mg can be given every four to six hours.
In patients thought to be at risk of acid aspiration syndrome an oral dose of 400mg can be given 90-120 minutes before induction of general anaesthesia or, in obstetric practice, at the start of labour. While such a risk persists, a dose of up to 400mg may be repeated at four hourly intervals as required up to the usual daily maximum of 2.4g. The usual precautions to avoid acid aspiration should be taken.
In the short bowel syndrome, e.g. following substantial resection for Crohn’s disease, the usual dosage range (see above) can be used according to individual response.
To reduce degradation of pancreatic enzyme supplements, 800-1600mg a day may be given according to response in four divided doses, one to one and a half hours before meals.
The normal adult dosage may be used unless renal function is markedly impaired (see Section 4.4).
Experience in children is less than that in adults. In children more than one year old, Tagamet 25-30mg/kg body weight per day in divided doses may be administered.
The use of Tagamet in infants under one year old is not yet fully evaluated; 20mg/kg body weight per day in divided doses has been used.
Oral; the tablets should be swallowed with a drink of water.
Acute overdosage of up to 20g has been reported several times with no significant ill-effects. Induction of vomiting and/or gastric lavage may be employed together with symptomatic and supportive therapy.
1. Blister packs consisting of 250µm clear PVC and 20µm hard temper aluminium foil contained in a carton.
Pack sizes: 60 & 120 tablets.
2. Polypropylene tubes with low density polyethylene caps. High density polyethylene film may be used as packing material.
Pack sizes: 100, 112, 250, 500 & 1000 tablets.