Opioid (pain reliever) infusion factsheet


When children have strong pain due to surgery, injury or illness, they need constant pain relief. Pain relieving medicine given in an infusion is a safe way of providing pain management. 

Morphine and some other strong pain relievers (opioids) can be given through an intravenous line (IV). This allows your child to receive pain relief constantly, without break or delay. 

If your child needs pain relief using an IV, the medical team involved in your child’s care will explain how pain relief works, the benefits and any potential side effects. 

 Preparing for the treatment

There are many safety features built into the IV infusion machine and policies into the way the medicine is ordered and administered for patients. 

The medical team will order the relevant infusion and check your child’s suitability for pain relieving IV before starting any treatment. Please tell someone in your medical team if you know your child has any medication allergies. 

 During the treatment

The dose of pain relieving medicine used is specific to your child’s weight and the amount needed to provide pain relief.  

The nurse will check your child often to assess their pain level, breathing rate, heart rate, oxygen levels, sleepiness, and if necessary, blood pressure. If you or your child have any questions or concerns between these checks, you can call the nurse to discuss further.  

As you know your child best, you play an important part in caring for your child and can help assess your child’s pain at and between these formal checks. 

While an opioid infusion is being used for your child, they will be reviewed by the medical team on a daily basis or as often as is deemed necessary. 

 After the treatment

The most common side effects of opioid pain relief are: 

  • nausea and vomiting 
  • constipation (difficulty and/or pain passing a bowel motion) 
  • itching 
  • opioids can make your child feel a little drowsy. If your child is able to sleep, it usually means your child’s pain is well controlled. Sleep is useful and helps with recovery from operations. If your child seems too sleepy or drowsy, please notify the medical team. 
  • opioids can slow down breathing. The effect of this depends on the amount of the opioids given. Some children with severe snoring or sleep apnoea (pauses in breathing) will be closely monitored and may need extra oxygen whilst on opioid treatment. 
  • a few children may have some mild behaviour changes or muddled thinking. These will disappear when the medicine has stopped but if you are worried, please notify the medical team. 

Your child’s doctor or nurse will be able to provide other medication to help with any of the above side effects whilst still provide the necessary pain relief for your child. 


Addiction to pain relief medication  

Children do not become addicted to the pain relieving medicine if it is being given to relieve pain from an operation or sickness. If the opioid infusion is used for more than a week, your child’s body may become used to the pain relieving medication, in which case it will be reduced slowly. 

After an operation, an opioid infusion is needed until the pain can be managed by oral pain medicine. Remember that every child is different, some operations can cause more pain and the infusion may be needed for longer. 

Your child may need pain-relieving medicines that can be given by mouth after this infusion is stopped. Your doctor will explain this process further for you. 

Last updated Tuesday 30th January 2024


This factsheet is provided for general information only. It does not constitute health advice and should not be used to diagnose or treat any health condition.

Please consult with your doctor or other health professional to make sure this information is right for you and/or your child.

The Sydney Children’s Hospitals Network does not accept responsibility for inaccuracies or omissions, the interpretation of the information, or for success or appropriateness of any treatment described in the factsheet.

© Sydney Children’s Hospitals Network 2024