Initiating morphine: immediate release method

In this step we describe how to initiate morphine using the immediate release formulation method. It is taken from NECN guidance.

To safely start a patient on a strong opioid using immediate release (IR) morphine, we recommend that prescribers follow the process below.

1. First prescribe regular analgesia

Prescribe 5mg of IR morphine to be taken every 4 hours. Liquid and tablet formulations are available. Advise the patient not to take IR morphine during the night if they are sleeping. Smaller doses can be prescribed if the patient is at risk of becoming toxic or experiencing side effects.

2. Next prescribe analgesia for breakthrough pain (BTP)

This is pain which occurs despite regular analgesia and can have various causes. If the patient experiences BTP they should be advised to take the same dose of IR morphine as that regularly-prescribed. They should continue to take the regular IR morphine as prescribed.

3. Review after 24 hours

It is important to review the patient at this point in time to establish whether the benefits of treatment outweigh the risks. This can be delegated to another healthcare professional.

4. If pain is controlled, continue the regimen for a further 24 hours

If it is still controlled after this time, go to step 8.

5. If pain is not controlled, take a full pain history

Is the pain is responding to morphine (is it better/ worse/ same?). If morphine isn’t helping, could it be neuropathic? In this case other medications may need to be considered and the opioid should be stopped. Converting to a different opioid is unlikely to be beneficial if the pain has not responded at all. Take specialist advice if necessary. If the pain is responding in part to morphine and the patient is not opioid toxic, go to step 7.

6. If the patient is sedated or shows signs of toxicity, reduce the morphine dose or increase dosing interval

We will discuss how to manage opioid toxicity later in this course.

7. Calculate the total amount of morphine taken in the previous 24 hours

Divide this dose by 6 - this is the new 4 hourly dose. Round up or down to nearest practical dose. Do not exceed a 50% increase. If the total amount of morphine is more than 50% of the previous 24 hour amount, consider whether the pain is opioid sensitive (step 5).

8. Once pain is controlled you should convert to 12 hourly, modified-release (MR) morphine

Calculate the total amount of morphine taken in the previous 24 hours. Divide this by 12 - this is the new 12 hourly (bd) dose of the modified-release (MR) morphine. Round up or down to the nearest practical dose.

9. Prescribe immediate release morphine for breakthrough pain

To calculate the breakthrough dose of immediate release (IR) morphine, divide the new total daily dose of morphine by 6 - this is the new 4 hourly dose.

10. Review after a further 24 hours and agree an ongoing review schedule

If pain is still not controlled, seek further advice.

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Opioid Analgesics: Treating Pain in People with Cancer

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