It is a selective H2 receptor antagonist, which can effectively inhibit gastric acid secretion caused by histamine, pentagastrin and food stimulation, and reduce the activity of gastric acid and gastric enzymes, but it has no effect on the secretion of gastrin and sex hormones. The effect is 5-8 times stronger than cimetidine, with high efficacy on gastric and duodenal ulcers, rapid and long-lasting effect, little side effects and safety. The average Cmax is 165ng/ml 30-90 minutes after a single oral dose of 80mg, and the effect lasts for 12 hours.

The product is rapidly absorbed and is not affected by food or antacids. Oral bioavailability is about 50% and t1/2 is about 2 to 2.7 hours, slightly longer than cimetidine. It can reduce gastric acid secretion induced by pentagastrin by 30% within 12 hours after oral administration. When 1mg/kg is injected, the instantaneous blood concentration is 3000ng/ml, and it can be maintained above 100ng/ml for up to 4 hours; the blood concentration reaches the peak in 30～60 minutes after drip at the rate of 0.5ng/kg per hour, and there is a positive correlation between the peak concentration and the dosage. Most of the product is excreted from the kidneys in its original form, with a renal clearance of 7.2 ml/kg per minute.

Small amounts are metabolized to N-oxides or S-oxides and demethylated analogs and excreted in the urine.24-hour urinary recovery of the original form and metabolites is 45% of the total oral dose.

This product is not the same as cimetidine, which has a 10-fold lower affinity for cytochrome P450 than the latter and thus does not interfere with warfarin, Diazepam and theophylline in the liver inactivation and metabolism process. Clinically, it is mainly used for the treatment of duodenal ulcers, benign gastric ulcers, postoperative ulcers, reflux esophagitis and Zuo - Ai syndrome. Intravenous injection can be used for upper gastrointestinal bleeding.