The purpose of this clinical multi-center study is to determine whether different doses of domperidone are effective in the treatment of feeding intolerance in premature infant

the premature infant have been divided into four group.The first group take the 0.2mg/kg/tds domperidone as treatment ,while the other group take the 0.4mg/kg/tds domperidone,0.6mg/kg/tds domperidone and the placebo respectively .

An objective index has been decided to evaluate the severity of feeding intolerance in the premature infant. 3kg/kg 5% glucose will be injected into the gastric tube .The residual glucose will be drawed out from the gastric tube. The residual percentage is the main result of the study.

The main result will be compared by the secondary result to help to explain the accuracy. The secondary result is the percentage of residual milk drawed out from the gastric tube from how many milk the infant take 3 hours ago.

Any adverse effect will be recorded and analysed to figure out whether is associate with the domperidone.

Inclusion Criteria:

• the residual milk and glucose over 55%
• abdominal distention or vomiting;
• Reduce,delay or disruption of enteral feeding

Exclusion Criteria:

• Four weeks before the start of this study had participated in other clinical trials
• pulmonary hypertension;
• Infants with necrotizing enterocolitis
• Gastrointestinal tract malformation, congenital heart disease
• Pre-existing QT extend/between long QT syndrome;
• ascites
• Have been used or will use drugs suppress CYP3A4
• Other risk factors for prolong the QT